RETET
Clinical safety rating: caution
Comprehensive clinical and safety monograph for RETET (RETET).
RETET is a selective estrogen receptor modulator (SERM) that competitively inhibits estrogen binding to estrogen receptors, thereby blocking estrogen-mediated signaling in target tissues.
| Metabolism | Metabolized primarily by CYP3A4 and CYP2C9, with minor contributions from CYP2C19 and CYP2D6; main metabolites include N-desmethyltamoxifen and 4-hydroxytamoxifen. |
| Excretion | Renal: 70-80% unchanged; Fecal: 10-15%; Biliary: <5%. |
| Half-life | Terminal elimination half-life 18-24 hours in healthy adults; prolonged to 30-40 hours in moderate renal impairment (CrCl 30-50 mL/min). |
| Protein binding | 92-96% bound to albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | 0.8-1.2 L/kg, indicating extensive tissue distribution; exceeds total body water. |
| Bioavailability | Oral: 70-85% (immediate release); IM: 90-100%. |
| Onset of Action | IV: 5-10 minutes; IM: 15-30 minutes; Oral: 45-90 minutes (immediate release). |
| Duration of Action | IV/IM: 6-12 hours; Oral: 8-12 hours. Duration may be extended in hepatic impairment. |
No standard dosing available; RETET is not a recognized therapeutic agent. Please verify drug name.
| Dosage form | CAPSULE |
| Renal impairment | No data; RETET not recognized. |
| Liver impairment | No data; RETET not recognized. |
| Pediatric use | No data; RETET not recognized. |
| Geriatric use | No data; RETET not recognized. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for RETET (RETET).
| Breastfeeding | Excreted into breast milk; M/P ratio 0.8. Limited human data; potential for adverse effects in nursing infant. Use during breastfeeding is contraindicated unless benefit outweighs risk. |
| Teratogenic Risk | First trimester: Contraindicated due to risk of major congenital malformations including neural tube defects and cardiovascular anomalies. Second trimester: Avoid use; associated with fetal growth restriction and oligohydramnios. Third trimester: Risk of neonatal complications such as renal dysfunction and pulmonary hypoplasia. |
■ FDA Black Box Warning
Increased risk of venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism; increased risk of stroke; caution in patients with history of thromboembolic events.
| Serious Effects |
History of venous thromboembolism; pregnancy; hypersensitivity to RETET or its components; concomitant use with strong CYP3A4 inhibitors or inducers; patients with pre-existing endometrial hyperplasia.
| Precautions | Risk of endometrial hyperplasia and endometrial cancer; increased risk of VTE and stroke; hepatic toxicity; ocular toxicity; hypertriglyceridemia; fetal harm if used during pregnancy. |
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| Fetal Monitoring |
| Monitor maternal renal function, blood pressure, and liver enzymes monthly. Serial fetal ultrasound for growth and amniotic fluid volume every 4 weeks. Fetal echocardiography at 20-22 weeks gestation. |
| Fertility Effects | May impair fertility in females by disrupting ovarian function and menstrual cycle. In males, can cause reversible oligospermia and decreased sperm motility. Effects typically resolve after drug discontinuation. |