OGEN .625
Clinical safety rating: caution
Comprehensive clinical and safety monograph for OGEN .625 (OGEN .625).
Estrogen replacement therapy; estrogen binds to estrogen receptors, which then translocate to the nucleus and modulate gene transcription, leading to effects such as proliferation of the endometrium and regulation of gonadotropin secretion.
| Metabolism | Primarily metabolized in the liver via CYP3A4; undergoes first-pass metabolism including sulfation and glucuronidation. Estropipate is hydrolyzed to estradiol and then metabolized. |
| Excretion | Renal (primarily as glucuronide and sulfate conjugates, ~50-80% of a dose), fecal (~10-20%), with enterohepatic recirculation. |
| Half-life | Estrone: 10-24 hours; equilin: 12-18 hours; terminal half-life supports once-daily dosing. |
| Protein binding | ~50-80% bound to sex hormone-binding globulin (SHBG) and albumin. |
| Volume of Distribution | Estrone: ~1-2 L/kg; indicates extensive tissue distribution. |
| Bioavailability | Oral: ~30-50% due to first-pass metabolism; micronized formulation enhances absorption. |
| Onset of Action | Oral: symptomatic relief of vasomotor symptoms begins within 2-4 weeks. |
| Duration of Action | Oral: 24 hours with once-daily dosing; steady-state estrogen effects maintained with continuous therapy. |
| Molecular Weight | 436.63 |
0.625 mg orally once daily
| Dosage form | TABLET |
| Renal impairment | No dose adjustment required for GFR ≥30 mL/min; insufficient data for GFR <30 mL/min, use with caution |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: contraindicated |
| Pediatric use | Not indicated for use in pediatric patients |
| Geriatric use | Use lowest effective dose; monitor for thromboembolic events and malignant neoplasms; no specific dose adjustment recommended |
| 1st trimester | Estropipate is contraindicated in pregnancy. Use during the first trimester may be associated with congenital anomalies, including cardiac defects and limb reduction defects. Estrogens should not be used during pregnancy. |
| 2nd trimester | Contraindicated in pregnancy. Estropipate is not indicated for use during the second trimester. Potential risks to the fetus include genitourinary tract abnormalities and other developmental effects. |
| 3rd trimester | Contraindicated in pregnancy. Estropipate may cause fetal harm when administered to a pregnant woman. Exposure to estrogens during the third trimester has been associated with an increased risk of vaginal adenosis and clear cell adenocarcinoma in female offspring later in life. |
Clinical note
Comprehensive clinical and safety monograph for OGEN .625 (OGEN .625).
| Placental transfer | Estropipate and its active metabolite, estradiol, are known to cross the placenta. Estrogens are transferred to the fetus, with fetal serum concentrations approximately 50% of maternal levels. |
| Breastfeeding |
■ FDA Black Box Warning
Estrogens increase the risk of endometrial carcinoma in postmenopausal women. Also, estrogens should not be used to prevent cardiovascular disease or dementia. Increased risks of myocardial infarction, stroke, invasive breast cancer, pulmonary emboli, and deep vein thrombosis have been reported with estrogen-alone therapy.
| Serious Effects |
Known or suspected pregnancyUndiagnosed abnormal genital bleedingKnown or suspected breast cancer (except in appropriately selected patients for treatment of metastatic disease)Known or suspected estrogen-dependent neoplasiaActive deep vein thrombosis or pulmonary embolismActive or recent arterial thromboembolic disease (e.g., stroke, myocardial infarction)Known thrombophilic disorders (e.g., protein C, protein S, or antithrombin deficiency)Known hypersensitivity to estropipate or any component of the productHepatic impairment or disease
| Precautions | Increased risk of endometrial cancer; cardiovascular disorders (MI, stroke, VTE); probable dementia; breast cancer; gallbladder disease; hypercalcemia; fluid retention; visual abnormalities; hereditary angioedema; exacerbation of asthma, diabetes, epilepsy, migraine, porphyria, SLE, and hepatic hemangiomas; hypothyroidism; elevated triglycerides; and hypersensitivity reactions. |
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| Estropipate is excreted in human milk. Estrogens have been shown to decrease the quantity and quality of breast milk. Use is generally not recommended during breastfeeding due to potential adverse effects on the infant, including jaundice and breast enlargement in male infants. Limited data suggest low levels in milk, but caution is advised. |
| Lactation Rating | L4 |
| Teratogenic Risk | First trimester: Estrogens are associated with a potential risk of fetal genital tract abnormalities, including congenital anomalies such as hypospadias and vaginal adenosis. Use is contraindicated in pregnancy. Second and third trimesters: Exposure may increase risk of fetal urogenital tract abnormalities, and estrogens have been linked to an elevated risk of vaginal clear cell adenocarcinoma in female offspring. Overall, use is contraindicated throughout pregnancy due to known fetal risks. |
| Fetal Monitoring | For women inadvertently exposed during pregnancy: Fetal ultrasound for genital anomalies, urogenital tract assessment. For pregnant patients, monitor for signs of fetal distress via nonstress test and biophysical profile as clinically indicated. Also monitor maternal blood pressure, weight gain, and blood glucose levels due to potential estrogenic effects on metabolic parameters. |
| Fertility Effects | Estropipate can inhibit ovulation and disrupt menstrual cycle regularity, potentially impairing fertility during use. Discontinuation of therapy restores normal cyclic function and fertility. Use as a component of menopausal hormone therapy does not enhance fertility; instead, it suppresses gonadotropin secretion and may delay conception. |
| Food/Dietary | Grapefruit juice may increase estrogen levels; avoid large quantities. No other significant food interactions. |
| Clinical Pearls | OGEN 0.625 mg (estropipate) is a conjugated estrogen tablet for hormone therapy. It may increase risk of endometrial cancer; use with progestin in women with intact uterus. Monitor for thromboembolic events. Not for prevention of cardiovascular disease or dementia. Avoid in pregnancy. |
| Patient Advice | Take exactly as prescribed; do not skip doses or stop without consulting your doctor. · Report any unusual vaginal bleeding, chest pain, shortness of breath, or vision changes immediately. · Avoid smoking as it increases risk of blood clots. · Inform all healthcare providers that you are taking estrogen. · Regular breast exams and mammograms are recommended. |