OGEN 5
Clinical safety rating: caution
Comprehensive clinical and safety monograph for OGEN 5 (OGEN 5).
Estrogen replacement; binds to estrogen receptors, activating gene transcription for estrogenic effects in target tissues.
| Metabolism | Primarily hepatic metabolism via CYP3A4 and other CYP enzymes; undergoes enterohepatic recirculation. |
| Excretion | Renal (primarily as conjugated metabolites); approximately 50-80% of an oral dose is excreted in urine, with about 20% in feces via biliary elimination. |
| Half-life | Terminal elimination half-life of estrone (primary active metabolite) is approximately 20 hours; steady-state concentrations achieved within 6-8 days. Half-life of estradiol is shorter (1-2 hours) but clinically the estrogenic effect correlates with estrone. |
| Protein binding | Estrone and estradiol: approximately 98% bound to sex hormone-binding globulin (SHBG) and albumin. |
| Volume of Distribution | Volume of distribution for estrogens: approximately 20 L/kg; indicates extensive distribution into tissues, including fat and reproductive organs. |
| Bioavailability | Oral estrone sulfate: approximately 30-50% due to first-pass metabolism in the liver and gut; interindividual variability due to differences in hydrolysis and conjugation. |
| Onset of Action | Oral administration: clinical effects (e.g., relief of menopausal symptoms) observed within 1-2 days; full estrogenic effect develops over 1-2 weeks. |
| Duration of Action | Duration of action after single oral dose: estrogenic effects persist for 12-24 hours; for chronic therapy, continuous dosing maintains effect as long as treatment is continued. |
| Molecular Weight | 436.59 |
0.625 mg orally once daily, adjusted based on response.
| Dosage form | TABLET |
| Renal impairment | No dose adjustment required for mild-to-moderate renal impairment; contraindicated in severe renal impairment. |
| Liver impairment | No specific guidelines; caution in severe hepatic disease. |
| Pediatric use | Not approved for use in pediatric patients. |
| Geriatric use | Use lowest effective dose; monitor for thromboembolic events and malignancy. |
| 1st trimester | Estropipate (OGEN 5) is generally contraindicated in the first trimester due to risk of fetal harm. Data from animal studies and human reports indicate potential for urogenital tract abnormalities and other teratogenic effects. Use only if clearly needed and no alternative therapy exists. |
| 2nd trimester | Use in second trimester is not recommended except for severe estrogen deficiency symptoms. May increase risk of fetal anomalies; avoid if possible. |
| 3rd trimester | Use is contraindicated in third trimester as estrogen use is associated with fetal adrenal suppression, delayed labor, and potential for urogenital abnormalities in the newborn. |
Clinical note
Comprehensive clinical and safety monograph for OGEN 5 (OGEN 5).
| Placental transfer | Estropipate (estrone sulfate) is known to cross the placenta. The degree is significant, with fetal serum concentrations approximately 5-10% of maternal levels. Active metabolites may affect fetal development. |
| Breastfeeding |
■ FDA Black Box Warning
Estrogens increase the risk of endometrial cancer in women with an intact uterus. Unopposed estrogen use is associated with an increased risk of endometrial hyperplasia and carcinoma. Cardiovascular disorders, breast cancer, and probable dementia have also been reported with estrogen therapy.
| Serious Effects |
Known or suspected pregnancyUndiagnosed abnormal genital bleedingKnown or suspected breast cancer (except for appropriately selected patients)Known or suspected estrogen-dependent neoplasiaActive deep vein thrombosis, pulmonary embolism, or history of these conditionsActive arterial thromboembolic disease (e.g., stroke, MI) or historyKnown liver dysfunction or diseaseKnown hypersensitivity to estropipate or any ingredientPorphyria
| Precautions | Cardiovascular disorders (e.g., stroke, DVT, pulmonary embolism), probable dementia (increased risk in women aged 65 years or older), breast cancer, endometrial cancer, gallbladder disease, hypercalcemia, visual abnormalities, and exacerbation of endometriosis. |
| Food/Dietary | Grapefruit juice may inhibit CYP3A4 metabolism of estrogens, increasing drug levels. Avoid concurrent consumption. No other significant food interactions reported. Maintain adequate calcium and vitamin D intake for bone health. |
Loading safety data…
| Estropipate is excreted into breast milk in small amounts, but may reduce milk production and quality. The American Academy of Pediatrics considers estrogens compatible with breastfeeding, but caution is advised. Use lowest effective dose for shortest duration. |
| Lactation Rating | L3 (Moderately Safe) - Limited data suggest risk is low but not negligible; consider risk-benefit. |
| Teratogenic Risk | Estrogen use during pregnancy is contraindicated. First trimester exposure associated with vaginal adenosis and clear cell adenocarcinoma in female offspring; second and third trimester use may cause urogenital anomalies and feminization of male fetuses. Risk of fetal harm is established. |
| Fetal Monitoring | Monitor maternal blood pressure, signs of thromboembolism, and uterine growth. Fetal ultrasound for anomalies if exposed. |
| Fertility Effects | Estrogens may suppress ovulation and interfere with fertility; used therapeutically for contraception. Reversible upon discontinuation. |
| Clinical Pearls | OGEN 5 (estropipate) is an esterified estrogen tablet (0.75 mg estropipate equivalent to 0.625 mg conjugated estrogens) used for menopausal hormone therapy. It has a slower absorption and a more stable serum estradiol level compared to conjugated equine estrogens. Monitor for endometrial hyperplasia when used without progestin in women with an intact uterus. Contraindicated in history of breast cancer, thromboembolic disorders, and liver disease. |
| Patient Advice | Take this medication exactly as prescribed; do not skip doses. · Report any unusual vaginal bleeding, breast lumps, or signs of blood clots (sudden chest pain, shortness of breath, leg swelling) immediately. · Avoid grapefruit juice as it may increase estrogen levels. · This medication does not protect against sexually transmitted infections or HIV. · Inform your healthcare provider if you smoke, as smoking increases the risk of blood clots. · Routine mammograms and pelvic exams are recommended while on this therapy. |