NORLUTATE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for NORLUTATE (NORLUTATE).
Progestin that suppresses gonadotropin secretion, inhibits ovulation, and induces endometrial transformation.
| Metabolism | Hepatic via hydroxylation and conjugation; CYP3A4 involved. |
| Excretion | Primarily renal (approximately 60% of metabolites, mostly glucuronides), with about 40% fecal/biliary elimination. Less than 1% excreted unchanged. |
| Half-life | Terminal elimination half-life is approximately 5-6 hours. Clinical context: supports twice-daily dosing; steady state reached within 2 days. |
| Protein binding | Approximately 80% bound, primarily to albumin and sex hormone-binding globulin (SHBG). |
| Volume of Distribution | Vd approximately 0.5-0.8 L/kg, indicating distribution into total body water and some tissue binding. |
| Bioavailability | Oral: Approximately 60-70% due to first-pass hepatic metabolism. No parenteral formulations available in USA. |
| Onset of Action | Oral: 2-4 hours for progestational effect on endometrium. Not available for parenteral routes. |
| Duration of Action | Oral: Approximately 12 hours, consistent with twice-daily dosing for contraception or endometrial protection. |
5 mg orally once daily for 5 days, starting on day 1 of menstrual cycle; for menorrhagia, 5 mg orally three times daily from day 19 to day 26 of cycle.
| Dosage form | TABLET |
| Renal impairment | No dosage adjustment required for GFR >30 mL/min; for GFR 10-30 mL/min, use with caution and consider 50% dose reduction; for GFR <10 mL/min, avoid use. |
| Liver impairment | Contraindicated in severe hepatic impairment (Child-Pugh class C); for mild to moderate impairment (Child-Pugh class A or B), no specific adjustment recommended but monitor liver function. |
| Pediatric use | Not indicated for pediatric use; safety and efficacy not established. |
| Geriatric use | No specific geriatric adjustment; use with caution due to potential increased sensitivity and comorbidities. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for NORLUTATE (NORLUTATE).
| Breastfeeding | Excreted in breast milk. M/P ratio not established. Use with caution; potential for adverse effects in nursing infant, especially hepatotoxicity and androgenization. Weigh risk vs benefit. |
| Teratogenic Risk | First trimester: Avoid; associated with masculinization of female fetuses (clitoral hypertrophy, labial fusion). Second and third trimesters: Avoid unless essential; may cause fetal androgenization. No adequate human studies; animal studies show adverse effects. Pregnancy category X. |
| Fetal Monitoring |
■ FDA Black Box Warning
None.
| Serious Effects |
["Known or suspected pregnancy","Undiagnosed vaginal bleeding","Known or suspected breast cancer","Active thromboembolic disorder","Severe hepatic disease"]
| Precautions | ["Thrombotic disorders","Cigarette smoking increases cardiovascular risk","Breast cancer risk","Hepatic disease","Depression"] |
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| Monitor fetal development with ultrasound; assess for signs of virilization in female fetuses. Monitor maternal liver function tests, lipid profile, blood pressure, and glucose levels. Discontinue if pregnancy suspected. |
| Fertility Effects | May suppress ovulation, luteal phase defects, and interfere with menstrual cycle. Return to fertility after discontinuation is typically prompt. Not for use as a contraceptive. |