Elagolix (Orilissa) - Comprehensive Research Paper

1. Summary

Elagolix sodium (brand name Orilissa) is a groundbreaking oral gonadotropin-releasing hormone (GnRH) receptor antagonist that represents a paradigm shift in the management of hormone-dependent gynecological conditions. Approved by the FDA in July 2018 for moderate to severe endometriosis-associated pain and later incorporated into Oriahnn (a combination product) in May 2020 for uterine fibroid-associated heavy menstrual bleeding, elagolix is the first oral medication in its class and the first new endometriosis treatment approved in over a decade.

FDA-Approved Indications:

• Orilissa (elagolix alone): Management of moderate to severe pain associated with endometriosis (July 2018)
• Oriahnn (elagolix + estradiol + norethindrone acetate): Management of heavy menstrual bleeding associated with uterine fibroids in premenopausal women (May 2020)

Mechanism of Action:

Elagolix is a highly potent, nonpeptide GnRH receptor antagonist (dissociation constant KD = 54 pM) that competitively inhibits endogenous GnRH signaling by binding to GnRH receptors in the anterior pituitary gland. This competitive antagonism rapidly and reversibly suppresses the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), leading to dose-dependent reduction in ovarian sex hormone production, particularly estradiol.

Key Distinction from GnRH Agonists:

Unlike GnRH agonists (leuprolide, goserelin) which cause an initial 1-2 week "flare-up" of hormone stimulation before receptor downregulation and full suppression, GnRH antagonists like elagolix provide:

• Immediate suppression (no flare-up period)
• Rapid and reversible onset and offset
• Dose-dependent modulation (partial to full suppression based on dose)
• Oral administration (vs injectable depot formulations)

Dose-Dependent Estrogen Suppression:

Elagolix offers flexible, titratable therapy:

• 150 mg once daily: Partial estrogen suppression; balances efficacy with tolerability
• 200 mg twice daily: Nearly full estrogen suppression; maximal efficacy but more hypoestrogenic side effects

This dose-dependent suppression allows individualized tailoring based on symptom severity and patient tolerance.

Clinical Efficacy - Endometriosis Pain (Elaris EM-I and EM-II Trials):

The pivotal phase 3 trials (Elaris EM-I and EM-II) enrolled women with surgically diagnosed endometriosis and moderate to severe endometriosis-associated pain.

Dysmenorrhea (Menstrual Pain) Response at 3 Months:

• Elagolix 150 mg once daily: 46.4% (EM-I), 43.4% (EM-II)
• Elagolix 200 mg twice daily: 75.8% (EM-I), 72.4% (EM-II)
• Placebo: 19.6% (EM-I), 22.7% (EM-II)
• P<0.001 for all comparisons vs placebo

Non-Menstrual Pelvic Pain Response at 3 Months:

• Elagolix 150 mg once daily: 50.4% (EM-I), 49.8% (EM-II)
• Elagolix 200 mg twice daily: 54.5% (EM-I), 57.8% (EM-II)
• Placebo: 36.5% (both trials)
• P<0.001 for all comparisons vs placebo

Long-Term Efficacy:

• Sustained pain reductions maintained through 12 months of treatment
• Dysmenorrhea response rates: 52.1-55.8% (150 mg), 75.9-78.2% (200 mg)
• Non-menstrual pelvic pain response: 66.4-67.5% (150 mg), 67.2-69.1% (200 mg)

Dosing:

• 150 mg once daily: For up to 24 months
• 200 mg twice daily: For up to 6 months (higher hypoestrogenic effects limit duration)
• Taken with or without food
• May be initiated at any time during menstrual cycle

Side Effects:

Most Common (Hypoestrogenic Effects):

• Hot flashes: 24% (150 mg once daily), 48% (200 mg twice daily)
• Night sweats
• Headache
• Nausea
• Amenorrhea (cessation of menstruation; expected therapeutic effect)

Serious Concerns:

Bone Mineral Density (BMD) Loss:

• Dose- and duration-dependent bone loss
• After 6 months: -0.3% to -1.3% (150 mg once daily); -2.5% to -3.1% (200 mg twice daily)
• After 12 months: further progressive loss
• May not be fully reversible upon discontinuation (only partial recovery observed 12 months post-treatment)

Contraindications:

• Known osteoporosis (BMD T-score ≤ -2.5)
• Pregnancy (may increase risk of miscarriage in early pregnancy)
• Severe hepatic impairment (7-fold increase in drug exposure)
• Concomitant use with strong OATP1B1 inhibitors (cyclosporine, gemfibrozil)

Cost and Access:

Brand-Name Only (No Generic):

• Elagolix is not available as a generic
• Patent exclusivity expected until approximately 2030
• This represents a significant access barrier compared to older therapies

Pricing:

• Without insurance: $1,122 to $1,600+ per month
• With commercial insurance: May pay as little as $5/month with manufacturer savings card
  • Maximum savings: $5,000 per calendar year
  • Not valid for Medicare/Medicaid patients
• Patient Assistance Program: Up to 12 months free medication for eligible uninsured patients

Insurance Coverage:

• Many commercial plans cover Orilissa but may require prior authorization
• Medicare generally does not cover Orilissa (may be included in rare Part D formularies)
• Coverage highly variable between plans

Add-Back Therapy (Oriahnn - For Uterine Fibroids):

To mitigate hypoestrogenic side effects (bone loss, hot flashes) while maintaining efficacy, AbbVie developed Oriahnn, a combination product containing:

• Elagolix 300 mg
• Estradiol 1.0 mg
• Norethindrone acetate 0.5 mg

Add-Back Rationale:

• Estradiol and norethindrone replace suppressed endogenous hormones
• Significantly reduces hot flashes and night sweats
• Markedly attenuates bone mineral density loss
• Maintains efficacy for uterine fibroid-associated heavy menstrual bleeding

Oriahnn Results:

• BMD remained relatively stable up to 48 months with add-back therapy (<2% decrease across sites)
• Compared to elagolix monotherapy, add-back therapy significantly reduced bone loss
• Duration limited to 24 months despite add-back due to residual bone loss concerns

Clinical Use:

Ideal Candidates for Elagolix (Orilissa):

• Premenopausal women with moderate to severe endometriosis-associated pain
• Failed or inadequate response to hormonal contraceptives or NSAIDs
• Desire to avoid or delay surgery (laparoscopy/excision)
• Not seeking pregnancy during treatment period
• No contraindications (normal bone density, no osteoporosis, normal liver function)

Not Recommended:

• Women with osteoporosis or osteopenia (relative contraindication)
• Pregnancy or planning pregnancy
• Severe hepatic impairment
• Unable to afford medication (no generic; high cost without insurance or savings programs)
• Women requiring long-term treatment beyond 24 months (bone loss concerns)

Comparison to GnRH Agonists (Leuprolide - Lupron):

• Elagolix advantages: Oral (vs injectable), immediate effect (no flare-up), dose-titratable, longer approved duration (150 mg for 24 months vs leuprolide typically 6-12 months)
• Leuprolide disadvantage: Injectable (monthly or every 3 months), initial flare-up requiring add-back therapy, full suppression only (no partial suppression option)
• Similar: Both cause hypoestrogenic side effects (bone loss, hot flashes); both reduce endometriosis pain significantly
• Cost-effectiveness: Elagolix found to be cost-effective vs leuprolide in modeling studies
• Patient preference: Patients prefer elagolix profile (oral, titratable) over leuprolide in surveys

2. Goal Archetype Integration

Primary Classification: GnRH Antagonist - Endometriosis/Uterine Fibroids (Oral)

Goal Archetype Mapping

Clinical Goal Scenarios

Scenario 1: Moderate to Severe Dysmenorrhea from Endometriosis

• Goal: Significant reduction in menstrual pain without surgical intervention
• Elagolix Advantage: Oral administration, immediate effect (no flare), dose-titratable
• Outcome: 46-76% dysmenorrhea response depending on dose; sustained relief

Scenario 2: Non-Menstrual Pelvic Pain from Endometriosis

• Goal: Reduce chronic pelvic pain affecting daily function
• Elagolix Advantage: Partial estrogen suppression option (150 mg) balances efficacy with tolerability
• Outcome: 50-58% response rate for non-menstrual pelvic pain

Scenario 3: Heavy Menstrual Bleeding from Uterine Fibroids

• Goal: Reduce menstrual blood loss; avoid or delay surgery
• Elagolix Advantage: Oriahnn (with add-back) provides efficacy with attenuated bone loss
• Outcome: Significant reduction in menstrual blood loss; fibroid shrinkage

Scenario 4: Failed Hormonal Contraceptive Therapy

• Goal: Alternative approach after inadequate response to CHCs or progestins
• Elagolix Advantage: More profound hormonal suppression than contraceptives
• Outcome: Second/third-line option with higher efficacy for refractory cases

Scenario 5: Desiring Future Pregnancy

• Goal: Manage endometriosis pain while preserving fertility
• Elagolix Advantage: Rapid reversibility; ovulation returns within 1-2 months
• Outcome: Bridge therapy until pregnancy desired; no permanent fertility impact

GnRH Antagonist vs. Agonist Goal Alignment

When This Compound Makes Sense

• Premenopausal women with moderate to severe endometriosis-associated pain
• Failed response to first-line therapy (hormonal contraceptives, progestins)
• Desire to avoid or delay surgical intervention
• Need for titratable therapy (partial vs. full suppression)
• Preference for oral medication over injections
• Rapid symptom relief needed (no flare acceptable)
• Heavy menstrual bleeding from fibroids (Oriahnn formulation)

When to Choose Something Else

• Known osteoporosis (T-score less than -2.5): Contraindicated; use progestins or surgery
• Need for treatment beyond 24 months: Cumulative bone loss limits duration; consider surgery
• Severe hepatic impairment: Contraindicated; 7-fold exposure increase
• Cost prohibitive without insurance/assistance: GnRH agonist generics or progestins more affordable
• Medicare/Medicaid coverage needed: Generally not covered; leuprolide may have better coverage
• Concomitant cyclosporine or gemfibrozil: Contraindicated interaction
• Postmenopausal women: No indication; low baseline estrogen negates mechanism

DosingIQ Goal Integration

Elagolix should be flagged as preferred when:

• Patient has moderate to severe endometriosis pain refractory to first-line therapy
• Oral medication strongly preferred over injectable GnRH agonists
• Rapid onset of action needed (no tolerance for 2-week flare)
• Duration of 6-24 months anticipated
• Baseline bone density is normal (T-score greater than -1.0)
• Access to manufacturer savings programs or adequate insurance coverage
• Patient not taking OATP1B1 inhibitors (cyclosporine, gemfibrozil)

3. FDA Approval History and Regulatory Timeline

First FDA Approval - Orilissa for Endometriosis (July 23, 2018)

Elagolix (brand name Orilissa) was approved by the U.S. FDA on July 23, 2018 for the management of moderate to severe pain associated with endometriosis. This milestone represented the first oral treatment for moderate to severe endometriosis-associated pain to receive FDA approval in over a decade, and the first oral GnRH antagonist approved for any indication in the United States.

Initial Indication (2018):

• Management of moderate to severe pain associated with endometriosis
• Two approved dosing regimens:
  • 150 mg once daily (for up to 24 months)
  • 200 mg twice daily (for up to 6 months)

Manufacturer:

• Developed by AbbVie in collaboration with Neurocrine Biosciences
• Marketed under brand name Orilissa

Supporting Clinical Trials:

• Elaris Endometriosis I (EM-I)
• Elaris Endometriosis II (EM-II)
• Extension studies: Elaris EM-III and EM-IV (long-term safety and efficacy)

Regulatory Significance: This approval was groundbreaking for several reasons:

1. First oral GnRH antagonist for gynecological use in U.S.
2. First new endometriosis medication approved in over 10 years
3. Dose-titratable therapy allowing individualized treatment
4. Longer approved duration than traditional GnRH agonists (24 months for lower dose vs typical 6-12 months for agonists)

Second FDA Approval - Oriahnn for Uterine Fibroids (May 29, 2020)

On May 29, 2020, the FDA expanded the regulatory scope for elagolix-based therapy with the approval of Oriahnn, a combination product containing:

• Elagolix 300 mg
• Estradiol 1.0 mg
• Norethindrone acetate 0.5 mg

Indication (2020):

• Management of heavy menstrual bleeding associated with uterine fibroids in premenopausal women
• Administered as once-daily capsules
• Approved duration: Up to 24 months

Add-Back Therapy Rationale: The combination of elagolix with estradiol and norethindrone acetate (hormonal "add-back therapy") addresses a critical limitation of GnRH antagonist/agonist monotherapy: severe hypoestrogenic side effects, particularly bone mineral density loss and vasomotor symptoms (hot flashes, night sweats). The add-back hormones replace the suppressed endogenous hormones at levels sufficient to mitigate side effects while maintaining therapeutic efficacy for fibroid-associated bleeding.

Supporting Clinical Trials:

• Phase 3 trials in women with uterine fibroid-associated heavy menstrual bleeding
• Extension studies demonstrating up to 48 months of data (though FDA approval limited to 24 months due to bone loss concerns)

Regulatory Distinction:

• Orilissa (elagolix alone): FDA-approved for endometriosis pain only
• Oriahnn (elagolix + add-back): FDA-approved for uterine fibroid bleeding only
• These are distinct products with distinct indications; they are not interchangeable

Current FDA-Approved Indications (2025)

As of 2025, elagolix-based therapies have the following FDA approvals:

Orilissa (Elagolix Sodium Tablets):

1. Management of moderate to severe pain associated with endometriosis
   • 150 mg once daily for up to 24 months, OR
   • 200 mg twice daily for up to 6 months

Oriahnn (Elagolix/Estradiol/Norethindrone Acetate Capsules):

1. Management of heavy menstrual bleeding associated with uterine fibroids in premenopausal women
   • One capsule once daily for up to 24 months

Limitations of Use:

Orilissa:

• Should not be used for longer than 24 months (150 mg) or 6 months (200 mg twice daily) due to bone loss
• Contraindicated in women with known osteoporosis
• Not indicated for treatment of uterine fibroids

Oriahnn:

• Duration limited to 24 months due to bone loss despite add-back therapy
• Not indicated for treatment of endometriosis

Important Regulatory Notes:

Boxed Warning (Oriahnn): Oriahnn contains a boxed warning for:

• Thromboembolic disorders and vascular events: Combination hormonal therapy (estradiol + norethindrone) increases risk of deep vein thrombosis, pulmonary embolism, stroke, and myocardial infarction
• Contraindicated in women with history of thromboembolism or stroke

Pregnancy Warning (Both Products):

• Elagolix may increase risk of early pregnancy loss
• Women should use effective non-hormonal contraception during treatment
• Discontinue immediately if pregnancy occurs

Manufacturer Information

Developed and Marketed By:

• AbbVie Inc. (primary manufacturer and marketer)
• Neurocrine Biosciences (collaboration partner in development)

Brand Names:

• Orilissa: Elagolix tablets (150 mg, 200 mg)
• Oriahnn: Elagolix/estradiol/norethindrone acetate capsules

Generic Availability:

• NO generic currently available
• Patent exclusivity expected to last until approximately 2030
• This represents a significant barrier to access due to high cost

Goal Relevance:

• Manage severe menstrual pain associated with endometriosis
• Reduce heavy menstrual bleeding due to uterine fibroids
• Alleviate non-menstrual pelvic pain linked to endometriosis
• Find an oral alternative to injectable treatments for endometriosis
• Minimize hot flashes and night sweats while treating gynecological conditions
• Address bone density concerns while managing uterine fibroid symptoms

4. Mechanism of Action

Gonadotropin-Releasing Hormone (GnRH) Physiology

To understand how elagolix works, it is essential to first understand the hypothalamic-pituitary-gonadal (HPG) axis:

Normal HPG Axis Function:

1. Hypothalamus releases gonadotropin-releasing hormone (GnRH) in a pulsatile manner
2. GnRH binds to GnRH receptors on gonadotroph cells in the anterior pituitary gland
3. GnRH receptor activation stimulates the pituitary to release gonadotropins:
   • Luteinizing hormone (LH)
   • Follicle-stimulating hormone (FSH)
4. LH and FSH act on the ovaries to stimulate:
   • Follicle development
   • Ovulation
   • Production of sex hormones (primarily estradiol and progesterone)
5. Estradiol and progesterone exert negative feedback on the hypothalamus and pituitary, modulating GnRH and gonadotropin release

Role of Estradiol in Endometriosis:

Endometriosis is an estrogen-dependent chronic inflammatory disease characterized by the presence of endometrial-like tissue outside the uterus, typically on pelvic organs, peritoneum, and ovaries. Estrogen plays a critical role in endometriosis pathophysiology:

• Promotes implantation of endometrial tissue in ectopic locations
• Proliferative effects on endometriotic lesions (stimulates cell division)
• Anti-apoptotic effects (prevents cell death, allowing lesions to persist)
• Stimulates local and systemic inflammation (prostaglandins, cytokines)
• Nerve fiber proliferation and sensitization (contributing to pain)

Suppression of estradiol production is therefore a central therapeutic strategy for endometriosis.

Elagolix: GnRH Receptor Antagonist

Elagolix is a highly potent, nonpeptide, orally bioavailable GnRH receptor antagonist.

Molecular Characteristics:

• Dissociation constant (KD): 54 pM (picomolar)
• This extremely low KD indicates very high binding affinity for the GnRH receptor
• Nonpeptide structure (small molecule) enables oral bioavailability

Mechanism of Action:

Elagolix competitively binds to GnRH receptors on gonadotroph cells in the anterior pituitary gland, blocking the binding of endogenous GnRH. This competitive antagonism:

1. Rapidly suppresses gonadotropin (LH and FSH) release

   • Inhibition occurs within hours of first dose
   • No initial "flare-up" of hormone stimulation (unlike GnRH agonists)

2. Reduces ovarian sex hormone production

   • Decreased LH and FSH lead to reduced ovarian stimulation
   • Dose-dependent reduction in serum estradiol and progesterone levels

3. Provides dose-dependent, reversible suppression

   • Lower doses (150 mg once daily): Partial estrogen suppression
   • Higher doses (200 mg twice daily): Nearly full estrogen suppression
   • Flexible modulation of the HPG axis

4. Rapid offset upon discontinuation

   • Competitive antagonism is reversible
   • HPG axis function returns rapidly after stopping medication
   • Menstruation typically resumes within 1-2 months

Dose-Dependent Estrogen Suppression

A key advantage of elagolix is the ability to titrate the degree of estrogen suppression based on dose:

150 mg Once Daily:

• Partial estrogen suppression
• Serum estradiol reduced but not to post-menopausal levels
• Maintains some estrogenic effects on bone and other tissues
• Balances efficacy (pain reduction) with tolerability (fewer hypoestrogenic side effects)
• Lower bone loss: -0.3% to -1.3% at 6 months
• Fewer hot flashes: 24%
• Approved for up to 24 months

200 mg Twice Daily:

• Nearly full estrogen suppression
• Serum estradiol reduced to levels approaching surgical menopause
• Maximal efficacy for pain reduction
• Higher hypoestrogenic side effects
• Greater bone loss: -2.5% to -3.1% at 6 months
• More hot flashes: 48%
• Approved for up to 6 months only (bone loss concerns limit duration)

This dose-dependent modulation allows individualized tailoring of therapy: lower doses for milder symptoms or women at higher risk for bone loss; higher doses for severe symptoms requiring maximal suppression.

Comparison: GnRH Antagonists vs GnRH Agonists

Understanding the difference between GnRH antagonists (elagolix) and GnRH agonists (leuprolide, goserelin, nafarelin) is critical:

Clinical Implications:

GnRH Agonist "Flare" Problem: GnRH agonists initially stimulate GnRH receptors, causing a surge in LH, FSH, and subsequently estradiol before receptors become desensitized and downregulated. This 1-2 week flare can:

• Temporarily worsen endometriosis pain
• Increase bleeding
• Require concurrent add-back therapy or GnRH antagonist pretreatment

GnRH Antagonist Advantage: Elagolix provides immediate suppression without flare, offering faster symptom relief and eliminating the need for flare management.

Dose Titration Advantage: Elagolix's dose-dependent suppression allows finding the "sweet spot" that balances efficacy with side effects, whereas GnRH agonists provide only full suppression (medical menopause with severe hypoestrogenic effects).

Effects on Endometriosis Pathophysiology

By reducing estradiol levels, elagolix addresses multiple pathophysiological mechanisms of endometriosis:

1. Lesion Regression:

• Reduced estrogen deprives endometriotic lesions of proliferative stimulus
• Lesions may shrink or become inactive
• Inflammatory activity decreases

2. Anti-Inflammatory Effects:

• Reduced estrogen decreases local production of prostaglandins (pain mediators)
• Decreased cytokine production (IL-1, IL-6, TNF-α)
• Reduced inflammatory cell infiltration

3. Pain Reduction:

• Direct effect: reduced prostaglandin production
• Indirect effect: reduced nerve fiber proliferation and sensitization
• Decreased pelvic inflammation

4. Ovulation Suppression:

• Reduced LH surge prevents ovulation
• Absence of ovulation eliminates cyclic hormonal fluctuations that can exacerbate endometriosis pain
• Many women experience amenorrhea (absence of menstruation), eliminating menstrual pain

Effects on Uterine Fibroids (Oriahnn - Combination Product)

When combined with add-back therapy (Oriahnn), elagolix reduces heavy menstrual bleeding associated with uterine fibroids:

Mechanisms:

1. Fibroid Shrinkage:

• Reduced estrogen deprives fibroids of growth stimulus
• Fibroids are estrogen-dependent; suppression causes shrinkage
• Smaller fibroids produce less pressure and bleeding

2. Endometrial Thinning:

• Reduced estrogen causes endometrial atrophy
• Thinner endometrium bleeds less during menstruation
• Combined effect with fibroid shrinkage reduces menstrual blood loss

3. Ovulation Suppression:

• Absence of ovulation eliminates cyclic hormonal stimulation
• Reduces endometrial proliferation and subsequent shedding

5. Dosing Guidelines

Standard Dosing for Endometriosis (Orilissa)

Elagolix is available in two oral dosing regimens for endometriosis-associated pain, chosen based on severity of symptoms and patient tolerability:

Lower-Dose Regimen:

• 150 mg once daily
• Taken at approximately the same time each day
• Can be taken with or without food
• Duration: Up to 24 months maximum

Higher-Dose Regimen:

• 200 mg twice daily (total 400 mg/day)
• One dose in morning, one dose in evening (approximately 12 hours apart)
• Can be taken with or without food
• Duration: Up to 6 months maximum (bone loss concerns limit longer use)

Initiation:

• May be started at any time during the menstrual cycle
• No need to wait for menstruation to begin
• No specific "loading dose" required

Effect of Food: A high-fat meal decreases elagolix plasma exposure by 24% (AUC) and 36% (Cmax). However, these reductions are not considered clinically significant, and elagolix can be taken with or without food. Consistency (always with food or always without) is not required.

Dosing for Uterine Fibroids (Oriahnn - Combination Product)

Oriahnn Dosing:

• One capsule once daily
• Each capsule contains:
  • Elagolix 300 mg
  • Estradiol 1.0 mg
  • Norethindrone acetate 0.5 mg
• Taken at approximately the same time each day
• With or without food
• Duration: Up to 24 months maximum

Important: Oriahnn is a different product from Orilissa and is FDA-approved only for uterine fibroid-associated heavy menstrual bleeding, not for endometriosis. The doses and formulations are not interchangeable.

Selection of Dose Regimen (Endometriosis)

Choose 150 mg Once Daily If:

• Moderate endometriosis pain (not severe)
• Desire for longer treatment duration (up to 24 months)
• Concern about bone density (lower dose causes less bone loss)
• Intolerance to severe hot flashes or other hypoestrogenic symptoms
• Lower-risk patient profile

Choose 200 mg Twice Daily If:

• Severe endometriosis pain requiring maximal suppression
• Failed response to 150 mg once daily (can escalate dose)
• Short-term treatment planned (≤6 months)
• Acceptable bone density and willing to accept higher hypoestrogenic effects for greater pain relief

Dose Escalation: If a patient starts on 150 mg once daily and has inadequate pain relief, the dose may be increased to 200 mg twice daily. However, this higher dose should not be used for more than 6 months total.

Dose De-escalation: If a patient on 200 mg twice daily achieves adequate pain control but experiences intolerable side effects, the dose may be reduced to 150 mg once daily.

Duration Limitations

Critical Safety Consideration:

Due to progressive, potentially irreversible bone mineral density (BMD) loss, the duration of elagolix treatment is strictly limited:

150 mg Once Daily:

• Maximum 24 months continuous use
• Bone loss at this dose: -0.3% to -1.3% at 6 months; progressive with longer treatment
• After 24 months, discontinuation required; not studied or recommended beyond this duration

200 mg Twice Daily:

• Maximum 6 months continuous use
• Bone loss at this dose: -2.5% to -3.1% at 6 months; more severe than lower dose
• After 6 months, must discontinue or reduce to 150 mg once daily (if total duration <24 months)

Re-Treatment After Discontinuation:

The safety and efficacy of re-treating with elagolix after completing a full course (24 months for 150 mg or 6 months for 200 mg) has not been established. Re-treatment is generally not recommended due to:

• Bone loss may not fully reverse (only partial recovery observed 12 months post-treatment)
• Cumulative bone loss with re-treatment unknown
• Risk of osteoporosis with repeated courses

If endometriosis pain recurs after discontinuing elagolix, alternative therapies should be considered (hormonal contraceptives, progestins, NSAIDs, surgery).

Dosing with Concomitant CYP3A or OATP1B1 Inhibitors

Elagolix is a substrate of CYP3A and OATP1B1 transporters. Concomitant use with inhibitors can significantly increase elagolix exposure, increasing risk of adverse effects (particularly bone loss).

With Strong CYP3A Inhibitors (Ketoconazole, Itraconazole, Clarithromycin, Ritonavir):

• If using 150 mg once daily: Limit treatment duration to 6 months (instead of 24 months)
• 200 mg twice daily: Limit to 1 month or avoid (instead of 6 months)
• Rationale: Ketoconazole increases elagolix exposure 2.2-fold; increased exposure increases bone loss risk

With Strong OATP1B1 Inhibitors (Cyclosporine, Gemfibrozil):

• Contraindicated - do not use elagolix with these medications
• These inhibitors significantly increase elagolix exposure
• Increased risk of bone loss and other adverse effects

With Moderate Inhibitors:

• Use caution; consider shorter treatment duration
• Monitor for increased side effects

Dosing in Special Populations

Hepatic Impairment:

• Mild hepatic impairment: No dose adjustment required
• Moderate hepatic impairment (Child-Pugh B):
  • Elagolix exposure increased approximately 3-fold
  • 200 mg twice daily: Do not use
  • 150 mg once daily: Limit to 6 months maximum
• Severe hepatic impairment (Child-Pugh C):
  • Elagolix exposure increased approximately 7-fold
  • Contraindicated - do not use

Renal Impairment:

• Elagolix exposure not affected by renal impairment (primarily hepatic metabolism and fecal excretion)
• No dose adjustment needed for any degree of renal impairment

Geriatric Patients:

• Elagolix is indicated for premenopausal women only
• Not studied or indicated in postmenopausal women or elderly
• Do not use

Pediatric Patients:

• Safety and efficacy not established in pediatric patients
• Not studied in women <18 years old
• Use not recommended

Missed Doses

If a Dose is Missed:

• Take as soon as remembered if on the same day
• Skip the missed dose if it is almost time for the next dose
• Do not double up to make up for a missed dose
• Resume regular dosing schedule

For 200 mg Twice Daily:

• If morning dose missed, take when remembered (even if close to evening dose time)
• If evening dose missed, skip and resume with morning dose next day

Administration Instructions

Tablet/Capsule Swallowing:

• Swallow whole with water
• Do not crush, chew, or break tablets (Orilissa) or capsules (Oriahnn)

Timing Consistency:

• While not strictly required, taking at the same time each day may improve adherence and maintain more consistent drug levels

Contraception Requirement:

• Women must use effective non-hormonal contraception during elagolix treatment
• Elagolix may reduce efficacy of hormonal contraceptives (CYP3A induction)
• Recommended methods: barrier (condoms, diaphragm), copper IUD, progestin-only methods (though interaction possible)

6. Contraindications and Warnings

Absolute Contraindications

Elagolix is contraindicated in the following situations:

1. Known Osteoporosis:

• Women with BMD T-score ≤ -2.5 (WHO definition of osteoporosis)
• History of osteoporotic fractures
• Rationale: Elagolix causes dose- and duration-dependent bone loss that may not be fully reversible; use in women with pre-existing osteoporosis significantly increases fracture risk

2. Severe Hepatic Impairment (Child-Pugh C):

• Elagolix exposure increased approximately 7-fold in severe hepatic impairment
• Risk of toxicity significantly elevated
• No safe dose in this population

3. Pregnancy:

• Elagolix may increase risk of early pregnancy loss (miscarriage)
• Limited human data, but animal studies show adverse reproductive effects
• Women must use effective non-hormonal contraception
• Discontinue immediately if pregnancy occurs

4. Concomitant Use with Strong OATP1B1 Inhibitors:

• Cyclosporine
• Gemfibrozil
• These medications significantly increase elagolix plasma concentrations
• Increased risk of adverse effects, particularly bone loss

Additional Contraindications for Oriahnn (Combination Product):

Due to the estradiol/norethindrone acetate component, Oriahnn has additional contraindications:

• Undiagnosed abnormal uterine bleeding
• Breast cancer or other estrogen- or progestin-sensitive cancers (current or history)
• Liver tumors (benign or malignant) or active liver disease
• Thromboembolic disorders: Active or history of DVT, PE, stroke, MI
• Thrombophilic disorders (Factor V Leiden, prothrombin mutation, etc.)
• Cerebrovascular or coronary artery disease
• Valvular heart disease with thrombogenic complications
• Uncontrolled hypertension
• Diabetes with vascular disease
• Headaches with focal neurological symptoms or migraine with aura (increased stroke risk)
• Pregnancy
• Known hypersensitivity to elagolix, estradiol, norethindrone acetate, or any component

Boxed Warning (Oriahnn Only)

The FDA-approved prescribing information for Oriahnn includes a BOXED WARNING highlighting serious risks associated with the combination hormonal therapy:

Estrogen-progestin combination therapy has been associated with an increased risk of:

• Deep vein thrombosis (DVT)
• Pulmonary embolism (PE)
• Stroke
• Myocardial infarction (MI)

Contraindications:

• Oriahnn is contraindicated in women with a history of these events or conditions that predispose to thromboembolic events
• Discontinue Oriahnn if thrombotic or thromboembolic event occurs

Risk Factors:

• Smoking (particularly age ≥35 years)
• Obesity
• Family history of VTE
• Prolonged immobilization
• Surgery

Note: This boxed warning applies to Oriahnn only (due to estradiol/norethindrone component), not to Orilissa (elagolix alone).

Major Warnings and Precautions

1. Bone Mineral Density (BMD) Loss:

Critical Safety Issue:

Elagolix causes dose- and duration-dependent bone loss that may not be completely reversible after discontinuation.

Magnitude of Bone Loss:

After 6 Months:

• 150 mg once daily: -0.3% to -1.3% (lumbar spine BMD)
• 200 mg twice daily: -2.5% to -3.1% (lumbar spine BMD)

After 12 Months:

• Progressive bone loss continues with longer treatment
• Dose-dependent: higher dose causes greater loss

Reversibility:

• After discontinuation, only partial recovery observed at 12 months
• Bone loss may not return to baseline
• Long-term consequences unknown

Screening and Monitoring:

• Baseline BMD: Consider DEXA scan before initiating therapy, especially in women with risk factors for osteoporosis
• Risk Factors: Low body weight, smoking, family history of osteoporosis, long-term corticosteroid use, eating disorders, excessive alcohol
• Contraindication: Do not use in women with known osteoporosis (T-score ≤ -2.5)
• Follow-Up BMD: Consider repeat DEXA after completing treatment to assess recovery

Duration Limitations:

• 150 mg once daily: Maximum 24 months
• 200 mg twice daily: Maximum 6 months
• Strictly enforce these limits to minimize bone loss

Counseling:

• Inform patients about bone loss risk
• Encourage calcium (1000-1200 mg/day) and vitamin D (600-800 IU/day) supplementation
• Weight-bearing exercise
• Smoking cessation
• Limit alcohol intake

2. Suicidal Ideation, Suicidal Behavior, and Mood Disorders:

Elagolix and other hormonal therapies for endometriosis have been associated with mood changes, including:

• Depression
• Mood swings
• Suicidal ideation and behavior

Monitoring:

• Assess for history of depression, anxiety, or other mood disorders before starting
• Monitor for new or worsening depression, anxiety, mood changes during treatment
• Educate patients to report mood changes immediately

Management:

• If significant mood changes occur, consider discontinuing elagolix
• Refer to mental health professional if indicated
• Alternative endometriosis treatments may be needed

3. Hepatic Transaminase Elevations:

Elagolix has been associated with dose-related elevations in serum transaminases (ALT, AST).

Monitoring:

• Consider baseline liver function tests (LFTs)
• Measure LFTs if symptoms of hepatotoxicity develop (jaundice, dark urine, fatigue, nausea, abdominal pain)
• Discontinue if ALT or AST >3x upper limit of normal (ULN) and bilirubin >2x ULN

4. Reduced Efficacy of Hormonal Contraceptives:

Elagolix is a weak to moderate inducer of CYP3A. This induction can reduce plasma concentrations of hormonal contraceptives that are CYP3A substrates, potentially reducing contraceptive efficacy.

Contraception Recommendations:

• Use non-hormonal contraception during elagolix treatment:
  • Copper IUD (most effective non-hormonal option)
  • Barrier methods (condoms, diaphragm with spermicide)
  • Consider progestin-only contraceptives (though elagolix may reduce efficacy)
• Avoid combined hormonal contraceptives (estrogen + progestin pills, patches, rings)

Note: Elagolix suppresses ovulation in many women (causing amenorrhea), but ovulation may still occur sporadically. Effective contraception is mandatory.

5. Pregnancy:

Pregnancy Risk:

• Elagolix may increase risk of early pregnancy loss
• Discontinue immediately if pregnancy occurs or is suspected
• Women should not use elagolix if planning pregnancy

Pregnancy Testing:

• Consider pregnancy test before initiating elagolix if pregnancy cannot be excluded

Return of Fertility:

• Ovulation and menstruation typically resume within 1-2 months of discontinuing elagolix
• Fertility may return rapidly; use contraception during treatment and for at least 28 days after discontinuation if not desiring pregnancy immediately

6. Moderate Hepatic Impairment:

Moderate hepatic impairment (Child-Pugh B) increases elagolix exposure approximately 3-fold.

Dose Modifications:

• 200 mg twice daily: Do not use
• 150 mg once daily: Limit to 6 months maximum (instead of 24 months)

7. Hypersensitivity Reactions:

Rare hypersensitivity reactions (angioedema, rash, urticaria) have been reported.

Management:

• Discontinue elagolix if hypersensitivity reaction occurs
• Do not rechallenge

7. Side Effects and Adverse Reactions

Common Side Effects (Incidence ≥10% in Clinical Trials)

Most side effects of elagolix are due to hypoestrogenic effects resulting from suppression of ovarian estradiol production. The incidence and severity are dose-dependent.

1. Hot Flashes (Vasomotor Symptoms):

Incidence:

• 150 mg once daily: 24%
• 200 mg twice daily: 48%
• Dose-dependent: higher dose nearly doubles incidence

Characteristics:

• Sudden sensation of intense heat, typically affecting face, neck, chest
• Flushing (skin redness)
• Sweating
• Duration: typically 2-5 minutes per episode
• Frequency varies (few per week to multiple per day)
• May be worse at night (night sweats)

Management:

• Non-pharmacologic: Layered clothing, fans, cool environment, avoid triggers (spicy food, alcohol, caffeine, stress), regular exercise
• Pharmacologic (if severe):
  • Venlafaxine 37.5-75 mg daily (effective for hot flashes; not a CYP2D6 inhibitor concern with elagolix)
  • Gabapentin 300-900 mg daily
  • Avoid estrogen (counterproductive; negates elagolix effect)
• Consider dose reduction: If on 200 mg twice daily, reduce to 150 mg once daily (fewer hot flashes but less pain relief)
• Add-back therapy: For uterine fibroids, Oriahnn (combination with estradiol/norethindrone) significantly reduces hot flashes compared to elagolix alone

2. Night Sweats:

• Common, often accompanying hot flashes
• Can disrupt sleep quality
• Management similar to hot flashes

3. Headache:

Incidence:

• Common (≥10%)
• Usually mild to moderate

Management:

• Acetaminophen or NSAIDs (ibuprofen, naproxen)
• Adequate hydration
• If severe or persistent, evaluate for other causes

4. Nausea:

Incidence:

• Common (≥10%)
• Usually mild
• Often transient (improves after first few weeks)

Management:

• Take with food (though not required, may reduce nausea)
• Ginger, peppermint
• If persistent, consider antiemetics (ondansetron, metoclopramide)

5. Amenorrhea (Absence of Menstruation):

Incidence:

• Very common, particularly at higher dose
• Expected therapeutic effect

Characteristics:

• Suppression of ovulation leads to absence of menstrual periods
• Light spotting or irregular bleeding may occur initially
• Amenorrhea more consistent with higher dose (200 mg twice daily)

Clinical Significance:

• Not harmful; this is the intended mechanism for reducing endometriosis pain
• Menstruation typically resumes within 1-2 months after discontinuing elagolix
• Patients should be counseled that amenorrhea is expected and does not indicate infertility or permanent damage

6. Fatigue:

• Common
• May be related to hot flashes disrupting sleep
• May improve over time

Management:

• Adequate sleep hygiene
• Regular exercise (paradoxically improves energy)
• Rule out other causes (anemia, thyroid dysfunction, depression)

7. Mood Changes:

Incidence:

• Mood swings, irritability, anxiety
• Depression (see Warnings section)

Management:

• Monitor for mood changes
• Mental health support if needed
• Consider discontinuation if severe

Serious Adverse Reactions

1. Bone Mineral Density (BMD) Loss:

Incidence:

• Occurs in virtually all patients; dose- and duration-dependent

Magnitude:

• See Warnings section (Section 5) for detailed BMD loss data

Clinical Significance:

• Progressive bone loss increases fracture risk
• May not be fully reversible
• Contraindicated in women with osteoporosis
• Strictly limit treatment duration

2. Suicidal Ideation and Behavior:

Incidence:

• Rare but serious
• Reported in postmarketing surveillance and clinical trials

Management:

• Screen for depression/mood disorders before starting
• Monitor during treatment
• Discontinue if suicidal ideation or behavior occurs
• Urgent psychiatric evaluation

3. Hepatic Transaminase Elevations:

Incidence:

• Dose-related
• ALT/AST elevations >3x ULN: uncommon but reported

Management:

• Check LFTs if symptoms of hepatotoxicity
• Discontinue if significant elevations or hepatotoxicity

4. Hypersensitivity Reactions:

Incidence:

• Rare

Types:

• Angioedema
• Rash
• Urticaria

Management:

• Discontinue elagolix
• Supportive care (antihistamines, corticosteroids if needed)

Less Common Side Effects (1-10% Incidence)

• Arthralgia (joint pain)
• Constipation
• Decreased libido
• Depression
• Diarrhea
• Insomnia
• Weight gain
• Anxiety
• Abdominal pain
• Dizziness

Comparison: Elagolix 150 mg vs 200 mg vs Placebo (Clinical Trials)

Understanding the dose-dependent side effect profile helps guide therapy selection:

Clinical Implication:

• If patient experiences intolerable hot flashes or excessive bone loss on 200 mg twice daily, consider dose reduction to 150 mg once daily
• If pain relief inadequate on 150 mg once daily, consider dose escalation to 200 mg twice daily (accepting higher side effect burden)

Comparison: Elagolix vs Elagolix + Add-Back (Oriahnn)

Add-back therapy (Oriahnn) significantly mitigates hypoestrogenic side effects:

Clinical Implication:

• Add-back therapy makes long-term treatment more tolerable
• Bone loss still occurs but is significantly less
• However, add-back therapy is FDA-approved only for uterine fibroids (Oriahnn), not endometriosis (Orilissa)

Managing Side Effects: General Principles

1. Patient Education:

• Counsel about expected side effects before starting
• Normalize common symptoms (hot flashes, amenorrhea)
• Provide written materials about warning signs requiring immediate attention (severe mood changes, suicidal thoughts)

2. Symptom Management:

• Hot flashes: Non-pharmacologic first, then venlafaxine or gabapentin if severe
• Nausea: Take with food, ginger, antiemetics if needed
• Headache: Acetaminophen, NSAIDs

3. Regular Monitoring:

• Assess side effects at follow-up visits (1-3 months, then every 3-6 months)
• Monitor for mood changes, depression
• Consider BMD monitoring (DEXA) before and after treatment

4. Dose Adjustment:

• If intolerable side effects on 200 mg twice daily, reduce to 150 mg once daily
• If inadequate efficacy on 150 mg once daily, increase to 200 mg twice daily (if total duration <6 months)

5. Discontinuation Criteria:

• Severe intolerable side effects not responding to management
• Suicidal ideation or significant depression
• Significant hepatic transaminase elevations
• Development of osteoporosis
• Patient preference

8. Clinical Efficacy and Research Evidence

Landmark Clinical Trials: Elaris EM-I and EM-II (Endometriosis)

The FDA approval of elagolix for endometriosis was based on two identical phase 3, randomized, double-blind, placebo-controlled trials: Elaris Endometriosis I (EM-I) and Elaris Endometriosis II (EM-II), published in the New England Journal of Medicine in 2017.

Study Design:

Enrollment:

• EM-I: 872 women
• EM-II: 817 women
• Total: 1,689 women with surgically diagnosed endometriosis

Eligibility:

• Age 18-49 years
• Surgically confirmed endometriosis (via laparoscopy or laparotomy) within 10 years
• Moderate to severe endometriosis-associated pain at baseline
• Regular menstrual cycles (21-38 days)

Intervention:

• Elagolix 150 mg once daily (lower-dose group)
• Elagolix 200 mg twice daily (higher-dose group)
• Placebo
• Duration: 6 months of treatment

Primary Efficacy Endpoints:

Two co-primary endpoints were specified:

1. Proportion of women with clinical response for dysmenorrhea at month 3
2. Proportion of women with clinical response for non-menstrual pelvic pain at month 3

Clinical Response Definition:

• Clinically meaningful reduction in pain score on daily diary
• Stable or reduced use of rescue analgesics (compared to baseline)

Results:

Dysmenorrhea (Menstrual Pain) Response at 3 Months:

Key Findings:

• Both doses significantly superior to placebo for dysmenorrhea
• Higher dose (200 mg twice daily) achieved response in approximately 3 out of 4 women
• Lower dose (150 mg once daily) achieved response in approximately half of women
• Consistent results across both independent trials

Non-Menstrual Pelvic Pain Response at 3 Months:

Key Findings:

• Both doses significantly superior to placebo for non-menstrual pelvic pain
• Magnitude of benefit smaller for non-menstrual pain than dysmenorrhea
• Dose-dependent trend (higher dose slightly better than lower dose)

Secondary Endpoints:

Dyspareunia (Pain with Intercourse):

• Significant improvements with both doses vs placebo
• Higher dose numerically better than lower dose

Quality of Life (EHP-30 Score):

• Significant improvements in endometriosis-specific quality of life with both doses
• Improvements in pain, social function, psychological well-being, self-image

Adverse Events:

• Hot flashes: 24% (150 mg), 48% (200 mg), 10% (placebo)
• BMD loss at 6 months: -0.3% to -1.3% (150 mg), -2.5% to -3.1% (200 mg), +0.5% to +1% (placebo)
• Dose-dependent hypoestrogenic effects

Clinical Significance:

The Elaris EM-I and EM-II trials demonstrated:

1. Clear efficacy for endometriosis-associated pain
2. Dose-dependent response: Higher dose more effective but more side effects
3. Consistent results across two large independent trials
4. Clinically meaningful improvements sustained through 6 months

Extension Studies: Elaris EM-III and EM-IV (Long-Term Efficacy and Safety)

Women who completed the 6-month Elaris EM-I or EM-II trials were eligible to enroll in extension studies (EM-III and EM-IV) to evaluate long-term efficacy and safety up to 12 months.

Results at 12 Months:

Dysmenorrhea Response:

• 150 mg once daily: 52.1% (EM-III), 55.8% (EM-IV)
• 200 mg twice daily: 78.2% (EM-III), 75.9% (EM-IV)

Non-Menstrual Pelvic Pain Response:

• 150 mg once daily: 67.5% (EM-III), 66.4% (EM-IV)
• 200 mg twice daily: 69.1% (EM-III), 67.2% (EM-IV)

Key Findings:

• Sustained efficacy through 12 months
• Response rates stable or improved from 6 to 12 months (no loss of effect)
• Long-term treatment with 150 mg once daily appears safe and effective for up to 24 months based on extension data

Bone Mineral Density at 12 Months:

• Progressive BMD loss continued with longer treatment
• Partial recovery observed 12 months after discontinuation, but not complete return to baseline

Uterine Fibroid Trials (Supporting Oriahnn Approval)

Phase 3 trials evaluated elagolix (300 mg twice daily) alone and in combination with add-back therapy (estradiol 1 mg + norethindrone acetate 0.5 mg) in women with uterine fibroid-associated heavy menstrual bleeding.

Key Findings:

Efficacy (Reduction in Menstrual Blood Loss):

• Elagolix + add-back significantly reduced heavy menstrual bleeding
• High response rates for achieving normal menstrual blood loss (<80 mL per cycle)

Bone Mineral Density:

• Elagolix monotherapy: Significant BMD loss (-3% to -5% over 6-12 months)
• Elagolix + add-back: Significantly attenuated BMD loss (<2% over 12 months; remained relatively stable up to 48 months)

Hot Flashes:

• Elagolix monotherapy: 40-50%
• Elagolix + add-back: 25-30% (significantly fewer and less severe)

Duration:

• Studies demonstrated safety and efficacy up to 48 months with add-back therapy
• FDA approved duration: 24 months (conservative limit due to residual bone loss despite add-back)

Clinical Significance: Add-back therapy makes long-term GnRH antagonist treatment tolerable by mitigating hypoestrogenic effects while maintaining efficacy.

8. Pharmacokinetics and Metabolism

Absorption

Oral Bioavailability:

• Elagolix is a small molecule, nonpeptide GnRH antagonist designed for oral bioavailability
• Absolute oral bioavailability in humans not fully characterized in FDA label
• Animal studies: Low oral bioavailability (5.8% in rats, 11% in monkeys) suggests significant first-pass metabolism in humans as well

Time to Peak Concentration (Tmax):

• 0.5 to 1.5 hours after oral administration
• Rapid absorption

Effect of Food:

• A high-fat meal decreases elagolix plasma exposure:
  • AUC (total exposure) reduced by 24%
  • Cmax (peak concentration) reduced by 36%
• These reductions are not considered clinically significant
• Elagolix can be taken with or without food

Distribution

Protein Binding:

• Data not extensively reported in FDA label
• Expected to be highly protein-bound (typical for small molecule drugs)

Volume of Distribution:

• Not extensively reported in FDA label

Metabolism

Primary Metabolic Pathway: CYP3A4

Elagolix is metabolized by multiple cytochrome P450 enzymes in vitro, with predominant contribution from CYP3A4 (approximately 50%).

Contributing Enzymes:

• CYP3A4: ~50% (predominant)
• CYP2D6: Minor contribution
• CYP2C8: Minor contribution
• UGT enzymes: Minor contribution (glucuronidation)

Clinical Implication:

• CYP3A4 inhibitors and inducers can significantly affect elagolix levels
• However, elagolix is not a sensitive CYP3A4 substrate (ketoconazole, a strong inhibitor, only increased elagolix AUC by 2.2-fold, whereas sensitive substrates typically increase >5-fold)

Elagolix as CYP3A Inducer:

Elagolix itself is a weak to moderate inducer of CYP3A in a dose-dependent manner:

• 150 mg once daily: Weak CYP3A induction (reduced midazolam AUC by 35%)
• 300 mg twice daily: Moderate CYP3A induction (reduced midazolam AUC by 54%)

Clinical Implication:

• Elagolix can reduce plasma concentrations of CYP3A substrates, including:
  • Hormonal contraceptives (ethinyl estradiol, progestins)
  • Many other medications
• This is a critical drug interaction (see Section 11)

Transporters

Elagolix is a substrate of:

• OATP1B1 (organic anion transporting polypeptide 1B1)
• P-glycoprotein (P-gp)

Clinical Implication:

• OATP1B1 inhibitors (cyclosporine, gemfibrozil) significantly increase elagolix levels → Contraindicated
• P-gp inhibitors (ketoconazole, ritonavir) may contribute to increased elagolix exposure

Elimination

Half-Life:

Elagolix has an apparent terminal elimination half-life of approximately 4-6 hours.

Implications:

• Rapid clearance: Drug is eliminated relatively quickly
• Twice-daily dosing (for 200 mg regimen) maintains more consistent drug levels
• Once-daily dosing (for 150 mg regimen) acceptable due to dose-dependent suppression and long duration of pharmacodynamic effect on HPG axis
• Rapid reversibility: Upon discontinuation, elagolix levels drop quickly; HPG axis recovers within days to weeks

Accumulation:

• The drug accumulation ratio indicates elagolix is not accumulated in the body with continuous administration
• Steady-state achieved within a few days

Routes of Excretion:

• Not extensively detailed in FDA label
• Typical for small molecules: combination of hepatic metabolism (fecal excretion of metabolites) and renal excretion
• Given extensive CYP metabolism, fecal excretion likely predominates

Pharmacokinetics in Special Populations

Renal Impairment:

• Elagolix exposure not affected by renal impairment
• No dose adjustment required for any degree of renal impairment
• Rationale: Predominantly hepatic metabolism; minimal renal clearance

Hepatic Impairment:

Hepatic impairment significantly affects elagolix pharmacokinetics:

Clinical Implication: Hepatic metabolism is critical for elagolix clearance. Severe impairment leads to dangerously high drug levels.

Age:

• Elagolix is indicated for premenopausal women (age 18-49 typically)
• No specific age-related pharmacokinetic changes expected within this population

Race/Ethnicity:

• No clinically significant differences in pharmacokinetics between racial/ethnic groups

9. Storage and Handling

Storage Conditions for Orilissa and Oriahnn

Temperature:

Elagolix products should be stored at room temperature with a relatively wide acceptable range:

• Recommended: 20°C to 25°C (68°F to 77°F)
• Acceptable range: 2°C to 30°C (36°F to 86°F)

Some sources specify storage at room temperature below 25°C for optimal stability.

Moisture and Light:

• Store in a closed container
• Protect from excess heat and moisture
• Do NOT store in bathroom (high humidity can degrade medication)
• Keep away from direct light

Original Container:

• Keep tablets/capsules in original bottle or blister pack
• Do not remove desiccant packet from bottle (if present)

Stability and Shelf Life

Finished Pharmaceutical Product:

• Stable for the duration of shelf life indicated on packaging when stored under recommended conditions
• Check expiration date on bottle; do not use after expiration

Research-Grade Compound (Elagolix Sodium Powder):

For research settings, more stringent storage is required for the raw chemical compound:

• Shipped: Ambient temperature (stable during shipping)
• Short-term storage (days to weeks): 0-4°C (refrigerator)
• Long-term storage (months to years): -20°C (freezer)
• In solvent: -80°C for 6 months; -20°C for 1 month

Clinical Implication: The finished pharmaceutical product (Orilissa, Oriahnn) is stable at room temperature and does not require refrigeration, making it convenient for patients. Research-grade compound requires cold storage.

Handling Precautions

For Patients:

• Wash hands after handling medication
• No special precautions needed for intact tablets/capsules
• If tablet/capsule breaks, wash hands thoroughly

For Healthcare Workers:

• Intact tablets/capsules: Standard precautions sufficient
• If compounding or handling powder: Use personal protective equipment (gloves, mask)

Pregnancy Precautions:

• Pregnant women or women trying to conceive should avoid handling crushed or broken elagolix tablets/capsules (Pregnancy Category: risk of miscarriage)
• If handling necessary, use gloves and wash hands

Disposal

Household Disposal:

Preferred Method - Drug Take-Back Programs:

• Return unused elagolix to authorized drug take-back sites
• Community pharmacy take-back programs
• DEA National Prescription Drug Take-Back Day events

If Take-Back Not Available - Household Trash:

Elagolix is NOT on the FDA Flush List (medications that can be flushed). Proper household trash disposal:

1. Remove tablets/capsules from original container
2. Mix with undesirable substance (coffee grounds, dirt, cat litter)
3. Place mixture in sealed plastic bag or container
4. Dispose in household trash
5. Remove personal information from prescription label before discarding bottle

Healthcare Facility Disposal:

• Follow institutional pharmaceutical waste disposal protocols
• Comply with state and federal regulations (EPA, DEA)

Packaging

Orilissa (Elagolix Tablets):

• Available as 150 mg tablets and 200 mg tablets
• Packaged in bottles (typical: 28-count or 56-count for monthly supply)
• Child-resistant caps

Oriahnn (Elagolix/Estradiol/Norethindrone Acetate Capsules):

• Combination capsules containing all three active ingredients
• Packaged in bottles or blister cards
• Child-resistant packaging

Travel Considerations

Traveling with Elagolix:

Carry-On vs Checked Luggage:

• Pack in carry-on to avoid loss and temperature extremes in cargo hold
• Bring enough medication for entire trip plus extra for delays

Documentation:

• Keep medication in original labeled bottle
• Bring prescription or physician's letter documenting need for medication
• Facilitates security screening and customs

International Travel:

• Check destination country regulations regarding medication importation
• Elagolix is not a controlled substance; rarely problematic
• Carry documentation from physician

Temperature Control:

• Elagolix is stable at room temperature (even up to 30°C/86°F)
• Generally no special temperature control needed
• Avoid leaving in very hot car (>40°C/104°F) for extended periods

Time Zones:

• Take at approximately same time each day relative to personal schedule
• When crossing time zones, gradually adjust dosing time over 1-2 days

Patient Education on Storage

Key Counseling Points:

1. Store at room temperature (not in bathroom)
2. Keep in original bottle with cap tightly closed
3. Protect from moisture and heat
4. Keep out of reach of children
5. Check expiration date; do not use expired medication
6. Do not share medication with others
7. Return unused medication to pharmacy take-back program

10. Cost and Generic Availability

Generic Availability

Current Status (2025):

• Elagolix is NOT available as a generic medication
• Only available as brand-name products:
  • Orilissa (elagolix tablets)
  • Oriahnn (elagolix/estradiol/norethindrone acetate capsules)

Patent Exclusivity:

• Patent exclusivity is expected to last until approximately 2030
• This delays generic competition for several more years
• No authorized generics currently available

Clinical Implication: The lack of generic availability represents a significant access barrier due to high cost. Patients without adequate insurance coverage or manufacturer assistance may find elagolix unaffordable.

Pricing and Cost

Retail Price (Without Insurance or Discounts):

Elagolix is expensive:

• Starting price: $1,122.13 per month (GoodRx, December 2025)
• Typical range: $1,191 to $1,600+ per month
• Annual cost: ~$14,000 to $19,000 per year without insurance

Cost Comparison by Dose:

• 150 mg tablets: $1,191.43 for 28 tablets (approximately 1-month supply for once-daily dosing)
• 200 mg tablets: Similar or higher cost; requires 56 tablets per month for twice-daily dosing

Why So Expensive?

• Brand-name only (no generic competition)
• Novel mechanism (first oral GnRH antagonist)
• Relatively small patient population (orphan-like pricing)
• Development costs amortized over smaller market

Insurance Coverage

Commercial/Private Insurance:

Coverage Status:

• Many commercial insurance plans cover Orilissa, but coverage varies widely
• Prior authorization often required
• Some plans may require:
  • Documentation of moderate to severe endometriosis-associated pain
  • Failed trial of other treatments (NSAIDs, hormonal contraceptives)
  • Surgical confirmation of endometriosis

Copays with Insurance:

• Tier 3 (Preferred Brand) or Tier 4 (Non-Preferred Brand/Specialty): Typical placement
• Copays: $50-$200+ per month depending on plan
• Deductibles: May apply before copays; patient may pay full cost until deductible met

Step Therapy:

• Some plans require trial of less expensive therapies first:
  • Combined hormonal contraceptives
  • Progestin-only therapy (medroxyprogesterone acetate)
  • NSAIDs
• Elagolix approved only after these fail or are contraindicated

Medicare:

Coverage Status:

• Medicare generally does NOT cover Orilissa
• May be included in some Medicare Part D formularies in uncommon situations
• Most Medicare beneficiaries are postmenopausal (outside indicated population), contributing to lack of coverage

Medicaid:

• Coverage varies by state
• Some states cover with prior authorization; others do not cover
• Check specific state Medicaid formulary

Manufacturer Savings Programs

AbbVie Savings Card (For Commercially Insured Patients):

Eligibility:

• Must have commercial/private insurance (not Medicare, Medicaid, or other government insurance)
• Prescription for Orilissa or Oriahnn
• Age 18 or older

Savings:

• Eligible patients may pay as little as $5 per monthly prescription
• Maximum savings: $5,000 per calendar year
• After reaching maximum, patient pays regular copay

How It Works:

• Apply online at Orilissa.com or Oriahnn.com
• Receive savings card (physical or digital)
• Present card at pharmacy with prescription
• Copay reduced to $5 (or as low as allowed by insurance)

Limitations:

• Not valid for Medicare or Medicaid patients (federal law prohibits manufacturer copay assistance for government programs)
• Not valid for uninsured patients (requires active commercial insurance)
• Subject to change; check current terms

Clinical Implication: For patients with commercial insurance, the savings card makes elagolix very affordable ($5/month is less than many generic medications). However, this excludes Medicare/Medicaid patients and uninsured individuals.

Patient Assistance Programs (PAPs)

AbbVie Patient Assistance Program:

Eligibility:

• Uninsured patients or patients whose insurance does not cover Orilissa/Oriahnn
• Income requirements (typically <400% of federal poverty level, though varies)
• U.S. residency required

Benefits:

• Up to 12 months of free medication for eligible patients
• Can reapply annually if still eligible

Application:

• Apply through AbbVie Patient Assistance website
• Healthcare provider completes portion of application
• Income verification required

Clinical Implication: Provides critical access for uninsured patients who cannot afford elagolix. However, application process can be burdensome, and income limits may exclude some patients.

Prescription Hope:

An independent patient assistance facilitator:

• Helps patients apply for manufacturer PAPs
• Flat monthly fee (~$70) covers multiple medications
• Facilitates application and renewal process

Discount Coupons (Limited Utility)

GoodRx, SingleCare, Blink Health:

These discount services provide minimal savings for elagolix:

• GoodRx: Still ~$1,122+/month (savings minimal)
• SingleCare: Similar pricing
• Reason: Brand-name medication with no generic competition; discounts limited

Clinical Implication: Unlike generic medications (where discount coupons can save 80-90%), elagolix coupons provide minimal benefit. Manufacturer savings card or PAP are far more effective.

Cost-Effectiveness

Despite high upfront cost, elagolix may be cost-effective compared to alternatives when considering total healthcare costs:

Cost-Effectiveness vs Leuprolide (GnRH Agonist):

• Modeling studies show elagolix is cost-effective vs leuprolide over 1- and 2-year horizons
• Factors:
  • Reduced need for add-back therapy (elagolix dose-titratable)
  • Oral (vs injectable; reduced administration costs)
  • Fewer office visits
  • Improved quality of life

Cost-Effectiveness vs Surgery:

• Surgical treatment of endometriosis (laparoscopic excision) costs $10,000-$30,000+
• Elagolix for 6-24 months may delay or avoid surgery
• However, surgery addresses anatomic disease; elagolix is symptom management only

Cost-Effectiveness vs Continuous Hormonal Contraceptives:

• Generic hormonal contraceptives: $10-$50/month (much cheaper)
• Elagolix more effective for endometriosis pain but vastly more expensive
• Typically elagolix reserved for patients who failed hormonal contraceptives

Value Proposition:

• Elagolix offers significant quality of life improvement for women with debilitating endometriosis pain
• For patients who respond, avoiding surgery and enabling return to work/normal function justifies cost
• However, access barriers due to cost remain significant

International Pricing

Developed Countries:

• Pricing and availability vary by country
• Many countries have not approved or have limited access to elagolix due to cost
• Not as widely available internationally as in U.S.

Developing Countries:

• Generally not available
• Cost prohibitive even if approved

Summary: Access and Affordability

Patients with Commercial Insurance + Savings Card:

• Highly affordable: $5/month
• Best-case scenario

Patients with Commercial Insurance (No Savings Card):

• Moderate to high cost: $50-$200+/month (copay)
• Still accessible for many

Uninsured Patients (Eligible for PAP):

• Free for 12 months if approved
• Must reapply annually

Medicare/Medicaid Patients:

• Generally NOT covered
• No savings card allowed (federal law)
• Access severely limited

Uninsured Patients (Not Eligible for PAP):

• Unaffordable: $1,000+/month
• Access essentially unavailable

Clinical Implication: Access to elagolix is highly dependent on insurance status and manufacturer assistance program eligibility. Medicare/Medicaid patients and uninsured individuals ineligible for PAP face significant barriers.

11. Drug Interactions

Elagolix has several clinically important drug interactions, primarily related to its metabolism by CYP3A4 and its role as a CYP3A inducer and substrate of OATP1B1 and P-gp transporters.

Elagolix as Victim Drug (Medications Affecting Elagolix Levels)

Strong CYP3A Inhibitors (Increase Elagolix Exposure)

Examples:

• Ketoconazole
• Itraconazole
• Clarithromycin
• Ritonavir
• Nelfinavir
• Indinavir
• Saquinavir
• Telithromycin
• Cobicistat

Effect: Ketoconazole 400 mg increased elagolix exposure:

• AUC increased 2.2-fold
• Cmax increased 1.8-fold

The similar increase in both Cmax and AUC suggests inhibition of intestinal P-gp may also contribute (in addition to CYP3A inhibition).

Clinical Significance:

• Increased elagolix exposure increases risk of adverse effects, particularly bone loss
• Higher drug levels may enhance efficacy but at cost of safety

Dose Adjustments:

When using Strong CYP3A Inhibitors with elagolix:

• 150 mg once daily: Limit treatment duration to 6 months maximum (instead of 24 months)
• 200 mg twice daily: Limit to 1 month or avoid use (instead of 6 months)

Rationale: Increased exposure accelerates bone loss; shorter duration limits cumulative bone loss.

Strong OATP1B1 Inhibitors (Significantly Increase Elagolix Exposure)

Examples:

• Cyclosporine
• Gemfibrozil

Effect: These medications inhibit OATP1B1 transporter, significantly increasing elagolix plasma concentrations.

Clinical Significance:

• Contraindicated - do not use elagolix concomitantly with cyclosporine or gemfibrozil
• Risk of severe adverse effects (bone loss, hepatotoxicity)

Strong CYP3A Inducers (Decrease Elagolix Exposure)

Examples:

• Rifampin
• Carbamazepine
• Phenytoin
• Phenobarbital
• St. John's Wort

Effect: Drug-drug interaction studies with rifampin (strong CYP3A and P-gp inducer) demonstrated significant reduction in elagolix levels.

Clinical Significance:

• Reduced elagolix exposure may decrease efficacy (inadequate pain relief)
• May result in treatment failure

Recommendation:

• Avoid concomitant use of strong CYP3A inducers with elagolix
• If unavoidable, monitor for reduced efficacy
• Consider alternative elagolix-free endometriosis therapy

Elagolix as Perpetrator Drug (Elagolix Affecting Other Medications)

CYP3A Induction by Elagolix (Reduces Levels of CYP3A Substrates)

Elagolix is a weak to moderate CYP3A inducer in a dose-dependent manner:

• 150 mg once daily: Weak inducer (reduced midazolam AUC by 35%)
• 300 mg twice daily: Moderate inducer (reduced midazolam AUC by 54%)

Clinical Significance:

Elagolix can reduce plasma concentrations of medications that are CYP3A substrates, potentially reducing their efficacy.

Most Important Interaction: Hormonal Contraceptives

Affected Hormonal Contraceptives:

• Combined oral contraceptives (ethinyl estradiol + progestin)
• Progestin-only pills
• Contraceptive patch
• Vaginal ring
• Potentially implants and injectables (to lesser extent)

Mechanism:

• Ethinyl estradiol and many progestins are CYP3A substrates
• Elagolix-induced CYP3A activity reduces their plasma levels
• Reduced hormone levels may decrease contraceptive efficacy

Clinical Recommendation:

Use Non-Hormonal Contraception During Elagolix Treatment:

• Copper IUD (most effective non-hormonal option)
• Barrier methods: Condoms, diaphragm with spermicide
• Consider progestin-only methods with caution (interaction possible but less well-characterized)

Do NOT rely on combined hormonal contraceptives while taking elagolix.

Other CYP3A Substrates Potentially Affected:

Elagolix may reduce levels of:

• Statins (atorvastatin, simvastatin, lovastatin)
• Calcium channel blockers (amlodipine, nifedipine, felodipine)
• Immunosuppressants (tacrolimus, cyclosporine, sirolimus)
• Benzodiazepines (midazolam, alprazolam, triazolam)
• Many others

Clinical Approach:

• Review patient's medication list for CYP3A substrates
• For critical medications (immunosuppressants, anticoagulants), monitor levels and clinical effect
• Dose adjustments may be needed

Other Drug Interactions

Warfarin:

• No specific interaction studies conducted
• CYP3A induction by elagolix could theoretically reduce warfarin levels (warfarin is partially metabolized by CYP3A)
• Monitor INR when starting or stopping elagolix in patients on warfarin
• Warfarin dose adjustments may be needed

Proton Pump Inhibitors (PPIs), H2 Blockers, Antacids:

• No significant interactions expected
• Elagolix absorption not pH-dependent

Alcohol:

• No specific interactions
• However, alcohol may exacerbate bone loss (independent elagolix effect)
• Recommend limiting alcohol intake

Summary Table: Key Drug Interactions

Patient Counseling on Drug Interactions

Key Points:

1. Inform all healthcare providers (physicians, dentists, pharmacists) that you are taking elagolix
2. Do not start new medications (including over-the-counter and herbal supplements) without discussing with prescriber
3. Use non-hormonal contraception during elagolix treatment (elagolix reduces efficacy of hormonal contraceptives)
4. Avoid St. John's Wort (reduces elagolix efficacy)
5. If prescribed cyclosporine or gemfibrozil, inform prescriber you are on elagolix (contraindicated combination)

12. Comparison to Other Medications

Elagolix vs GnRH Agonists (Leuprolide - Lupron Depot)

GnRH agonists (leuprolide, goserelin, nafarelin) have been the standard GnRH-targeting therapy for endometriosis for decades. Elagolix represents a new approach with important advantages and differences.

Mechanism Comparison:

Efficacy Comparison:

Both elagolix and leuprolide effectively reduce endometriosis-associated pain:

• Dysmenorrhea: Both highly effective (response rates 50-75% depending on dose/formulation)
• Non-menstrual pelvic pain: Both effective
• Pelvic tenderness: Both reduce on exam

Head-to-head trials limited, but indirect comparisons suggest similar efficacy for pain reduction.

Safety Comparison:

Bone Mineral Density Loss:

• Leuprolide: Severe bone loss (-3.2% at 6 months, -6.3% at 12 months); typically limited to 6-12 months due to bone concerns
• Elagolix 150 mg: Less bone loss (-0.3% to -1.3% at 6 months); can be used up to 24 months
• Elagolix 200 mg: Moderate bone loss (-2.5% to -3.1% at 6 months); limited to 6 months

Hot Flashes:

• Leuprolide: Very common (>60%); severe due to full estrogen suppression
• Elagolix 150 mg: Common (24%); less severe
• Elagolix 200 mg: Common (48%); comparable to leuprolide

Add-Back Therapy:

• Leuprolide: Often requires add-back therapy (progestin or estrogen-progestin) from initiation or after 6 months
• Elagolix 150 mg: Lower dose may not require add-back for many patients
• Elagolix 200 mg: Add-back may be beneficial but not FDA-approved for endometriosis (approved only for uterine fibroids - Oriahnn)

Advantages of Elagolix:

1. Oral administration (vs painful injections)
2. No flare-up (immediate symptom control)
3. Dose-titratable (150 mg for milder symptoms with fewer side effects; 200 mg for severe symptoms)
4. Longer approved duration (150 mg for 24 months vs leuprolide typically 6-12 months)
5. Rapid reversibility (menstruation resumes quickly after stopping)
6. Patient preference (surveys show patients prefer elagolix profile over leuprolide)

Disadvantages of Elagolix:

1. Cost ($1,000+/month vs leuprolide generics ~$200-$500/month)
2. Daily pill burden (vs once-monthly or every-3-month injection)
3. Drug interactions (CYP3A inducer; affects hormonal contraceptives)
4. No generic available (vs leuprolide acetate generics available)

Cost-Effectiveness:

Modeling studies demonstrate elagolix is cost-effective vs leuprolide over 1- and 2-year time horizons when considering:

• Total medication costs
• Administration costs (office visits for injections)
• Quality of life improvements
• Reduced need for add-back therapy

Clinical Decision-Making:

Choose Elagolix If:

• Patient preference for oral medication
• Desire for dose titration (partial suppression option)
• Longer treatment duration needed (up to 24 months)
• Immediate symptom relief desired (no flare)
• Can afford (insurance + savings card or PAP access)

Choose Leuprolide If:

• Cost constraint (generics available; Medicaid coverage better)
• Patient preference for less frequent dosing (monthly/quarterly injection)
• Established treatment with known efficacy
• Medicare coverage (elagolix not covered)

Elagolix vs Hormonal Contraceptives (Combined Oral Contraceptives)

Combined hormonal contraceptives (CHCs) are first-line medical therapy for endometriosis-associated pain.

Mechanism:

Hormonal Contraceptives:

• Suppress ovulation via feedback inhibition of FSH/LH
• Decidualize endometrium (make it thin and atrophic)
• Reduce menstrual flow
• Provide steady-state hormones (eliminate cyclic fluctuations)

Elagolix:

• Suppress FSH/LH via GnRH receptor antagonism
• Reduce estradiol production
• More profound hormonal suppression

Efficacy:

Hormonal Contraceptives:

• Effective for mild to moderate endometriosis pain
• Less effective for severe pain
• Often first-line treatment; ~50-70% pain reduction

Elagolix:

• More effective than CHCs for moderate to severe pain
• Typically reserved for patients who failed CHCs
• ~50-75% response rates (dose-dependent)

Side Effects:

Hormonal Contraceptives:

• Nausea, breast tenderness, headache, mood changes
• Breakthrough bleeding common initially
• VTE risk (small but present)
• Generally well-tolerated

Elagolix:

• Hypoestrogenic: hot flashes, bone loss
• More significant side effects than CHCs
• Tolerability challenges, especially at higher dose

Cost:

Hormonal Contraceptives:

• Generic pills: $10-$50/month (very affordable)
• Often free under ACA preventive services

Elagolix:

• $1,000+/month (without insurance/assistance)
• $5/month with manufacturer savings card (if eligible)
• Much more expensive baseline

Treatment Algorithm:

Typical Approach:

1. First-line: Combined hormonal contraceptives (continuous or cyclic)
2. Second-line: Progestins (norethindrone acetate, medroxyprogesterone acetate depot)
3. Third-line: Elagolix or GnRH agonists (for moderate to severe pain unresponsive to first/second-line)
4. Surgical: Laparoscopic excision/ablation if medical therapy fails

Choose Elagolix Over CHCs If:

• Failed trial of CHCs (inadequate pain relief)
• Contraindication to estrogen (VTE history, migraine with aura, etc.)
• Severe endometriosis pain requiring more profound suppression

Elagolix vs Progestins (Norethindrone Acetate, Depot Medroxyprogesterone Acetate)

Progestins are second-line medical therapy for endometriosis.

Mechanism:

Progestins:

• Decidualize and atrophy endometrium
• Suppress ovulation (at higher doses)
• Anti-inflammatory effects
• Direct effect on endometriotic implants

Elagolix:

• Suppress ovarian estrogen production
• More profound hormonal suppression

Efficacy:

Both effective for endometriosis pain; head-to-head comparisons limited.

DMPA (Depot Medroxyprogesterone Acetate) vs Elagolix:

• One study compared bone effects: elagolix caused similar or slightly less bone loss than DMPA at comparable doses
• Both effective for pain

Cost:

Progestins:

• Generic norethindrone acetate: $20-$50/month
• DMPA injection: $50-$150 per injection (every 3 months)
• Much less expensive than elagolix

Choose Elagolix Over Progestins If:

• Failed progestin trial
• Intolerance to progestins (irregular bleeding, mood changes, weight gain)
• Desire for more profound suppression

13. Special Considerations

Use in Premenopausal Women (Only Indicated Population)

Elagolix is only indicated for premenopausal women. All clinical trials enrolled premenopausal women aged 18-49 years.

Definition of Premenopausal:

• Regular or irregular menstrual cycles
• Have not experienced 12 consecutive months of amenorrhea (natural menopause)
• Intact ovaries (bilateral oophorectomy would render patient postmenopausal)

Why Premenopausal Only?

• Endometriosis is estrogen-dependent; postmenopausal women have low endogenous estrogen and typically do not have active endometriosis
• Suppressing already-low estrogen in postmenopausal women offers no benefit and causes harm (bone loss)
• Not studied or approved in postmenopausal women

NOT Indicated for Postmenopausal Women

Do NOT use elagolix in postmenopausal women:

• Safety and efficacy not established
• No therapeutic rationale (already have low estrogen)
• Would cause unnecessary bone loss

Contraception Requirements

Critical Importance:

Women taking elagolix MUST use effective non-hormonal contraception for two reasons:

1. Pregnancy risk: Elagolix may increase risk of miscarriage in early pregnancy
2. Reduced hormonal contraceptive efficacy: Elagolix induces CYP3A, reducing hormone levels in combined and progestin-only contraceptives

Recommended Contraceptive Methods:

Highly Effective Non-Hormonal:

• Copper IUD (ParaGard): Most effective; >99% efficacy
• Condoms + spermicide: Used consistently and correctly; ~85-98% efficacy
• Diaphragm with spermicide: ~88-94% efficacy with perfect use

Progestin-Only Methods (Use with Caution):

• Progestin-only pills, implants (Nexplanon), injections (Depo-Provera) may have reduced efficacy due to CYP3A induction
• If using, counsel about potential reduced efficacy and consider backup barrier method

Avoid:

• Combined hormonal contraceptives (pills, patch, ring) containing estrogen + progestin - efficacy significantly reduced

Duration:

• Use contraception throughout elagolix treatment
• Continue for at least 28 days after discontinuing elagolix (to ensure complete drug clearance and avoid pregnancy during washout)

Return of Fertility:

• Ovulation and menstruation typically resume within 1-2 months after stopping elagolix
• Fertility may return rapidly
• If not desiring immediate pregnancy, continue contraception after stopping elagolix

Pregnancy and Lactation

Pregnancy:

Risk:

• Elagolix may increase risk of early pregnancy loss (miscarriage)
• Animal studies show adverse reproductive effects
• Limited human data (medication stopped immediately upon pregnancy detection in trials)

If Pregnancy Occurs:

• Discontinue elagolix immediately
• Contact healthcare provider
• Prenatal care and monitoring

Pregnancy Testing:

• Consider pregnancy test before initiating elagolix if pregnancy cannot be excluded
• If menstrual period missed during treatment, perform pregnancy test

Lactation:

Unknown if Excreted in Human Milk:

• No data on presence in breast milk
• Effects on nursing infant unknown
• Effects on milk production unknown

Recommendation:

• Not recommended during breastfeeding
• Consider alternative endometriosis management in lactating women

Use in Adolescents

Age Range in Clinical Trials:

• Trials enrolled women aged 18 years and older
• Not studied in adolescents <18 years

FDA Approval:

• Approved for adults (age ≥18)
• Safety and efficacy not established in pediatric patients

Clinical Consideration:

• Endometriosis can affect adolescents
• Elagolix may be appropriate in select cases (age ≥18) with confirmed endometriosis and severe pain
• Bone health particularly important in adolescents (critical bone accrual period)
• Use lowest effective dose (150 mg once daily) and shortest duration
• Close monitoring of bone density essential

Use in Women with Osteopenia or Low Bone Density

Contraindication:

• Osteoporosis (T-score ≤ -2.5) is absolute contraindication

Osteopenia (T-score -1.0 to -2.5):

• Not an absolute contraindication but requires careful consideration
• Risk-benefit assessment:
  • Severity of endometriosis pain
  • Likelihood of benefit from elagolix
  • Risk of progression to osteoporosis
  • Availability of alternative therapies

If Elagolix Used in Woman with Osteopenia:

• Baseline DEXA scan essential
• Use lowest effective dose (150 mg once daily)
• Shortest possible duration
• Maximize bone protection:
  • Calcium 1200 mg/day
  • Vitamin D 800-1000 IU/day
  • Weight-bearing exercise
  • Smoking cessation
  • Limit alcohol
• Repeat DEXA after treatment to assess bone loss
• Consider bisphosphonate if significant bone loss or progression to osteoporosis

Use in Women Desiring Future Pregnancy

Key Considerations:

Fertility Preservation:

• Elagolix does not cause permanent infertility
• Ovulation and menstruation resume within 1-2 months after stopping
• Fertility returns rapidly

Treatment Strategy:

• Elagolix can be used in women who desire future pregnancy
• Discontinue elagolix 2-3 months before attempting conception (to allow complete washout and return of regular ovulation)
• Alternatively, use elagolix as bridge therapy to delay surgery while not actively trying to conceive

Pregnancy Planning:

• Stop elagolix
• Wait for return of menstruation (typically 1-2 cycles)
• Begin attempting conception
• Ensure folic acid supplementation (400-800 mcg/day) started before conception

Use in Women with Hepatic Impairment

See Section 5 (Contraindications) and Section 8 (Pharmacokinetics) for detailed information.

Summary:

• Mild (Child-Pugh A): No dose adjustment
• Moderate (Child-Pugh B): Do not use 200 mg BID; limit 150 mg QD to 6 months
• Severe (Child-Pugh C): Contraindicated

Use in Women with Renal Impairment

• No dose adjustment needed for any degree of renal impairment
• Elagolix metabolism is hepatic; renal clearance minimal

Switching from GnRH Agonist (Leuprolide) to Elagolix

Scenario: Woman currently on leuprolide depot (Lupron) for endometriosis; considering switch to elagolix.

Approach:

1. Complete Current Leuprolide Dose:

   • Allow leuprolide depot to fully elapse (1-month or 3-month depot)
   • Do not start elagolix until leuprolide effect wearing off

2. Transition Timing:

   • Start elagolix at time of next scheduled leuprolide injection
   • OR wait for return of menstruation after last leuprolide dose, then start elagolix

3. No Overlap:

   • Do not use leuprolide and elagolix concurrently (no additive benefit; both suppress HPG axis)

4. Monitor:

   • Assess efficacy after 3 months on elagolix
   • May require dose adjustment (150 mg vs 200 mg)

Switching from Hormonal Contraceptives to Elagolix

Scenario: Woman currently on combined hormonal contraceptives (CHCs) for endometriosis; inadequate pain relief; switching to elagolix.

Approach:

1. Discontinue CHCs:

   • Finish current pill pack OR stop mid-pack (depending on urgency)

2. Start Elagolix:

   • Can start elagolix at any time during menstrual cycle (no need to wait for menstruation)
   • If starting mid-cycle, use backup barrier contraception for first 7 days

3. Contraception Transition:

   • Before starting elagolix, place copper IUD or begin barrier methods
   • Do NOT continue CHCs (elagolix reduces their efficacy; also counterproductive to elagolix mechanism)

4. Monitor:

   • Expect amenorrhea after 1-3 months on elagolix (ovulation suppressed)
   • Assess pain improvement at 3 months

14. Citations and References

1. NICHD - Eunice Kennedy Shriver National Institute of Child Health and Human Development. Elagolix – The First FDA-Approved Treatment for Endometriosis and Uterine Fibroids. https://www.nichd.nih.gov/grants-contracts/SBIR_STTR/showcase/Elagolix

2. Ng J, Chwalisz K, Carter DC, Klein CE. Dose-dependent suppression of gonadotropins and ovarian hormones by elagolix in healthy premenopausal women. J Clin Endocrinol Metab. 2017;102(5):1683-1691.

3. Taylor HS, Giudice LC, Lessey BA, et al. Treatment of endometriosis-associated pain with elagolix, an oral GnRH antagonist. N Engl J Med. 2017;377(1):28-40.

4. Osuga Y, Enya K, Kudou K, et al. Oral gonadotropin-releasing hormone antagonist elagolix for endometriosis-associated pain: A randomized controlled trial. Obstet Gynecol. 2021;137(5):753-763.

5. Surrey E, Taylor HS, Giudice L, et al. Long-term outcomes of elagolix in women with endometriosis: Results from two extension studies. Obstet Gynecol. 2018;132(1):147-160.

6. AbbVie. AbbVie Receives U.S. FDA Approval of ORILISSA™ (elagolix) for the Management of Moderate to Severe Pain Associated with Endometriosis. Press Release, July 24, 2018.

7. Simon JA, Al-Hendy A, Archer DF, et al. Elagolix treatment for up to 12 months in women with heavy menstrual bleeding and uterine leiomyomas. Obstet Gynecol. 2020;135(6):1313-1326.

8. Polepally AR, Shirley S, Moreno EG, et al. Assessment of clinical drug-drug interactions of elagolix, a gonadotropin-releasing hormone receptor antagonist. J Clin Pharmacol. 2020;60(11):1485-1495.

9. Carr BR, Stewart EA, Archer DF, et al. Elagolix alone or with add-back therapy in women with heavy menstrual bleeding and uterine leiomyomas: A randomized controlled trial. Obstet Gynecol. 2018;132(5):1252-1264.

10. Schlaff WD, Ackerman RT, Al-Hendy A, et al. Elagolix for heavy menstrual bleeding in women with uterine fibroids. N Engl J Med. 2020;382(4):328-340.

11. U.S. Food and Drug Administration. ORILISSA (elagolix) tablets prescribing information. Accessed December 2025.

12. U.S. Food and Drug Administration. ORIAHNN (elagolix, estradiol, and norethindrone acetate) capsules prescribing information. Accessed December 2025.

13. Clinical Pharmacology of Elagolix: An Oral Gonadotropin-Releasing Hormone Receptor Antagonist for Endometriosis. Clin Pharmacokinet. 2020;59(3):297-309.

14. Nader A, Mostafa NM, Patel P, et al. Effects of elagolix on the pharmacokinetics of omeprazole and its metabolites in healthy premenopausal women. Clin Transl Sci. 2022;15(5):1228-1237.

15. Cost-effectiveness of elagolix versus leuprolide acetate for treating moderate-to-severe endometriosis pain in the USA. J Comp Eff Res. 2019;8(9):707-719.

16. A Clinician's Guide to the Treatment of Endometriosis with Elagolix. Int J Womens Health. 2021;13:443-452.

17. Elagolix in the treatment of heavy menstrual bleeding associated with uterine fibroids in premenopausal women. Int J Womens Health. 2021;13:703-714.

18. Bone mineral density with elagolix plus add-back therapy in women with heavy menstrual bleeding and uterine fibroids: Open-label and post-treatment results of a 60-month phase 3 trial. Fertil Steril. 2023;120(6):1253-1262.