TESLAC
Clinical safety rating: caution
Comprehensive clinical and safety monograph for TESLAC (TESLAC).
Androgen receptor inhibitor; suppresses gonadotropin secretion and reduces testosterone levels.
| Metabolism | Hepatic metabolism via reduction and conjugation. |
| Excretion | Renal (primarily as metabolites) and biliary/fecal. The drug is extensively metabolized; less than 5% is excreted unchanged in urine. |
| Half-life | Terminal half-life approximately 2-4 hours; clinical significance: requires multiple daily dosing for steady-state maintenance. |
| Protein binding | Approximately 90% bound to serum albumin. |
| Volume of Distribution | Vd approximately 0.3-0.5 L/kg, indicating distribution mainly into total body water. |
| Bioavailability | Oral bioavailability is approximately 30-40% due to extensive first-pass metabolism. |
| Onset of Action | Oral: Clinical effect observed within 1-2 hours. |
| Duration of Action | Duration of action is 6-8 hours based on receptor occupancy and clinical response. |
250 mg intramuscularly three times per week
| Dosage form | INJECTABLE |
| Renal impairment | No specific adjustment; contraindicated in severe renal impairment (CrCl <30 mL/min) due to sodium retention risk |
| Liver impairment | Contraindicated in severe hepatic impairment (Child-Pugh class C); use with caution in moderate impairment (Child-Pugh class B) with dose reduction to 125 mg three times per week |
| Pediatric use | Not recommended for use in pediatric patients |
| Geriatric use | Use with caution due to increased risk of fluid retention and electrolyte imbalances; consider lower starting dose of 125 mg three times per week |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for TESLAC (TESLAC).
| Breastfeeding | Excretion into breast milk unknown; due to potential androgenic effects, breastfeeding is not recommended. M/P ratio not available. |
| Teratogenic Risk | Teslac (testolactone) is contraindicated in pregnancy. Animal studies have shown androgenic effects, including virilization of female fetuses. In first trimester, risk of pseudohermaphroditism in female fetuses. Second and third trimester: potential clitoral enlargement, labial fusion. No adequate human studies; based on animal data and mechanism, risk is high. |
■ FDA Black Box Warning
None
| Serious Effects |
["Hypersensitivity","Severe hepatic impairment"]
| Precautions | ["Hepatotoxicity","Gynecomastia","Fluid retention","Hypercalcemia","Bone pain flare"] |
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| Fetal Monitoring |
| Maternal monitoring: serum calcium, liver function tests, glucose, and signs of hypercalcemia. Fetal: ultrasound for virilization if inadvertent exposure. Monitor for maternal metabolic disturbances. |
| Fertility Effects | May suppress ovulation due to androgenic activity; can cause menstrual irregularities and reduced fertility. Reversible upon discontinuation. In males, possible spermatogenesis suppression. |