ORIAHNN (COPACKAGED)
Clinical safety rating: caution
Comprehensive clinical and safety monograph for ORIAHNN (COPACKAGED) (ORIAHNN (COPACKAGED)).
ORIAHNN is a copackaged product containing elagolix (a GnRH receptor antagonist), estradiol, and norethindrone acetate. Elagolix competitively binds to GnRH receptors in the pituitary gland, reducing gonadotropin secretion and decreasing ovarian estrogen production. Estradiol and norethindrone acetate provide hormonal replacement to mitigate hypoestrogenic side effects and maintain endometrial stability.
| Metabolism | Elagolix is primarily metabolized by CYP3A; estradiol is metabolized by CYP1A2, CYP1A1, CYP3A4, and CYP2C9; norethindrone acetate is metabolized by CYP3A4. |
| Excretion | Elagolix: approximately 55-60% excreted as metabolites in urine (with <1% as unchanged drug) and 40-45% via feces. Estradiol (norethindrone acetate component): primarily metabolized; metabolites are excreted in urine (50-60%) and feces (20-30%). Norethindrone acetate: metabolized; metabolites are excreted in urine (50-60%) and feces (20-30%). |
| Half-life | Elagolix: terminal half-life is approximately 4-6 hours. Norethindrone acetate: terminal half-life is approximately 8-11 hours. Estradiol: terminal half-life is approximately 1-2 hours for endogenous estradiol, but with exogenous administration, half-life is prolonged due to continuous release. |
| Protein binding | Elagolix: ~80% bound to plasma proteins (albumin and α1-acid glycoprotein). Norethindrone acetate: ~61% bound to albumin; ~36% bound to sex hormone-binding globulin (SHBG). Estradiol: ~98% bound to SHBG and albumin. |
| Volume of Distribution | Elagolix: apparent Vd/F is approximately 20 L (0.3 L/kg for 70 kg patient); suggests moderate tissue distribution. Norethindrone acetate: Vd is approximately 4 L/kg, indicating extensive tissue distribution. Estradiol: Vd is approximately 1-2 L/kg, consistent with distribution to target tissues. |
| Bioavailability | Elagolix: oral bioavailability is approximately 40-50% under fasting conditions; food slightly decreases Cmax but does not affect AUC significantly. Norethindrone acetate: oral bioavailability is 60-70% with high interindividual variability. Estradiol: oral bioavailability is very low (<5%) due to extensive first-pass metabolism; however, in the combination product, it is administered as a prodrug (estradiol hemihydrate) to improve bioavailability. |
| Onset of Action | Oral: Therapeutic effect onset is typically within 1 month of initiating therapy for reduction of heavy menstrual bleeding associated with uterine fibroids. |
| Duration of Action | Duration of action is approximately 24 hours with once-daily dosing for elagolix component; however, clinical effect on heavy menstrual bleeding is sustained over consecutive cycles of therapy. Discontinuation leads to return of heavy bleeding within a few months. |
One capsule (elagolix 300 mg, estradiol 1 mg, norethindrone acetate 0.5 mg) orally once daily in the morning and one capsule (elagolix 300 mg) orally once daily in the evening, total daily dose: elagolix 600 mg. Duration limited to 24 months.
| Dosage form | CAPSULE |
| Renal impairment | Contraindicated in severe renal impairment (eGFR <15 mL/min/1.73 m²) or end-stage renal disease. No adjustment for mild to moderate impairment. |
| Liver impairment | Contraindicated in Child-Pugh Class C (severe hepatic impairment). Not recommended in Child-Pugh Class B. No adjustment for Child-Pugh Class A. |
| Pediatric use | Safety and efficacy not established in pediatric patients. |
| Geriatric use | Not indicated for postmenopausal women; no geriatric-specific studies. Use lowest effective dose if considered in elderly women of reproductive potential, but generally avoid due to thromboembolic risk. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for ORIAHNN (COPACKAGED) (ORIAHNN (COPACKAGED)).
| Breastfeeding | Contraindicated during breastfeeding. Elagolix and metabolites are excreted in human milk; M/P ratio not available. Relugolix, estradiol, and norethindrone acetate may reduce milk production and pass to infant. Risk of infant estrogenic effects and potential long-term adverse outcomes. Use alternative agents if breastfeeding. |
| Teratogenic Risk | ORIAHNN is contraindicated in pregnancy. Elagolix, a component, is associated with early pregnancy loss (risk of miscarriage 30-50%) and potential fetal harm based on animal studies. Relugolix, estradiol, and norethindrone acetate increase risk of fetal abnormalities, particularly with first-trimester exposure. Exposure in second and third trimesters may lead to masculinization of female fetuses (due to norethindrone) and potential estrogenic effects. Pregnancy test must be negative before initiation, and non-hormonal contraception is required. |
■ FDA Black Box Warning
WARNING: THROMBOEMBOLIC DISORDERS AND VASCULAR EVENTS. Estrogen-containing products, including ORIAHNN, increase the risk of thromboembolic disorders, including deep vein thrombosis, pulmonary embolism, stroke, and myocardial infarction. Discontinue at the earliest signs of thrombotic events.
| Serious Effects |
["Concomitant use with hormonal contraceptives or other estrogen-containing products","High risk of thrombosis or thromboembolic disorders (e.g., current or history of DVT, PE, stroke, MI)","Known thrombophilic disorders (e.g., factor V Leiden, protein C/S deficiency)","Current or past history of breast cancer or other estrogen-sensitive malignancies","Known or suspected pregnancy","Undiagnosed abnormal uterine bleeding","Hepatic impairment (Child-Pugh C)","Renal impairment (eGFR <30 mL/min/1.73 m²)","Hypersensitivity to any component"]
| Precautions | ["Risk of thromboembolic disorders and vascular events","Risk of bone loss (decreased bone mineral density) due to elagolix component","Risk of endometrial cancer with unopposed estrogen; use with progestin reduces risk","Hepatic impairment","Cardiovascular disease risk factors","Gallbladder disease","Hypertriglyceridemia","Fluid retention","Exacerbation of endometriosis","Depression","Effect on glucose tolerance","Elevations in blood pressure","Chloasma","Ocular abnormalities (e.g., retinal vascular thrombosis)"] |
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| Fetal Monitoring | Confirm negative pregnancy test before starting and monthly thereafter. Monitor for bone mineral density loss with DEXA scan at baseline and periodically (risk with elagolix). Assess liver function tests (ALT, AST) at baseline and monthly for first 3 months, then periodically. Monitor for heavy bleeding, signs of thromboembolism, and mood changes including depression. In case of accidental pregnancy, immediate discontinuation and referral to obstetrics for fetal assessment. |
| Fertility Effects | ORIAHNN is used for heavy menstrual bleeding and endometriosis-related pain. It suppresses ovulation, leading to reversible impaired fertility during treatment. After discontinuation, return to normal ovulatory function expected within weeks. No long-term negative effects on fertility reported; however, prolonged use may delay conception. |