TESTOSTERONE CYPIONATE-ESTRADIOL CYPIONATE
Clinical safety rating: avoid
Corticosteroids may increase edema risk and anticoagulants may have increased effects Can cause polycythemia and increased risk of cardiovascular events.
Testosterone cypionate is a prodrug of testosterone, which binds to androgen receptors and modulates gene expression, promoting male secondary sex characteristics and anabolic effects. Estradiol cypionate is a prodrug of estradiol, which binds to estrogen receptors and regulates gene transcription involved in female reproductive development and maintenance.
| Metabolism | Testosterone cypionate: Hydrolyzed to testosterone then metabolized primarily in the liver via oxidation (CYP3A4, CYP2C9) and conjugation; estradiol cypionate: Hydrolyzed to estradiol then metabolized via hydroxylation (CYP1A2, CYP3A4) and glucuronidation. |
| Excretion | Renal (90% as glucuronide and sulfate conjugates, less than 5% as unchanged drug); fecal (approximately 10%). |
| Half-life | Testosterone cypionate: approximately 8 days; estradiol cypionate: approximately 8-10 days. Clinical context: steady-state reached in 3-5 weeks. |
| Protein binding | Testosterone: 97-99% bound to sex hormone-binding globulin (SHBG) and albumin; estradiol: 98% bound to SHBG and albumin. |
| Volume of Distribution | Testosterone: approximately 0.6 L/kg; estradiol: approximately 0.5 L/kg. Indicates distribution into peripheral tissues. |
| Bioavailability | Intramuscular: approximately 100% due to slow release from oil depot; no oral bioavailability (hepatic first-pass inactivation). |
| Onset of Action | Intramuscular injection: therapeutic effects (e.g., libido, hot flash relief) noted within 1-2 weeks. |
| Duration of Action | Intramuscular injection: 2-4 weeks. Clinical note: dosing interval typically every 4 weeks due to prolonged release. |
Testosterone cypionate 50-200 mg and estradiol cypionate 2-10 mg intramuscularly every 2-4 weeks.
| Dosage form | INJECTABLE |
| Renal impairment | No specific dose adjustment recommended; use with caution in severe impairment due to limited data. |
| Liver impairment | Contraindicated in severe hepatic impairment (Child-Pugh C). For mild to moderate (Child-Pugh A or B), use with caution and monitor hepatic function. |
| Pediatric use | Not recommended for pediatric use; safety and efficacy not established. |
| Geriatric use | Use lower end of dosing range (e.g., testosterone cypionate 50-100 mg with estradiol cypionate 2-5 mg every 4 weeks) due to increased risk of cardiovascular and prostate adverse effects; monitor closely. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Corticosteroids may increase edema risk and anticoagulants may have increased effects Can cause polycythemia and increased risk of cardiovascular events.
| FDA category | Contraindicated |
| Breastfeeding | Contraindicated during breast-feeding. Excreted in breast milk, may cause masculinization of female infant. M/P ratio not known. |
| Teratogenic Risk | First trimester: High risk of masculinization of female fetus. Second trimester: Androgenic effects may cause clitoral enlargement, labial fusion, and urogenital sinus abnormalities. Third trimester: Possible advanced bone age and growth acceleration. Not recommended in any trimester. |
■ FDA Black Box Warning
Estrogens, with or without progestins, should not be used for the prevention of cardiovascular disease or dementia. Increased risks of endometrial cancer, stroke, and deep vein thrombosis. Venous thromboembolism risk is increased with estrogen-containing products.
| Common Effects | Acne |
| Serious Effects |
["Pregnancy (estrogen component)","Breast cancer (known, suspected, or history, unless appropriate indication)","Estrogen-dependent neoplasia","Undiagnosed abnormal genital bleeding","Active thromboembolic disease or history of thromboembolism (e.g., DVT, PE)","Known hypersensitivity to components","Men with prostate or breast cancer (testosterone component)"]
| Precautions | ["Cardiovascular risk: increased risk of myocardial infarction, stroke, venous thromboembolism","Endometrial cancer: unopposed estrogen use increases risk","Breast cancer: caution in patients with known or suspected estrogen-dependent tumors","Hepatic impairment: dose adjustment may be needed","Hypercalcemia: caution in patients with bone metastases","Fluid retention: caution in cardiac or renal dysfunction"] |
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| Fetal Monitoring | Monitor maternal blood pressure, signs of hypercalcemia, hepatic function, lipid profile, and blood glucose. Fetal ultrasound for signs of sexual ambiguity or growth abnormalities. |
| Fertility Effects | May suppress ovulation and impair fertility in women. In men, high doses may suppress spermatogenesis. Discontinuation may restore fertility. |