TESTODERM TTS
Clinical safety rating: caution
Comprehensive clinical and safety monograph for TESTODERM TTS (TESTODERM TTS).
Testosterone is an androgen receptor agonist. It binds to and activates androgen receptors, leading to changes in gene expression that promote the development and maintenance of male secondary sexual characteristics, anabolic effects, and spermatogenesis.
| Metabolism | Testosterone is metabolized primarily in the liver via reduction and conjugation, with CYP3A4 isoenzyme involvement. Also metabolized to dihydrotestosterone (DHT) by 5α-reductase and to estradiol by aromatase. |
| Excretion | Testosterone is excreted primarily in the urine as glucuronide and sulfate conjugates (approximately 90%), with about 6% excreted in feces via bile. Less than 1% is excreted unchanged. |
| Half-life | The terminal elimination half-life of testosterone administered transdermally is approximately 1.5–2 hours. This short half-life requires daily application of the patch to maintain therapeutic levels. |
| Protein binding | Testosterone is extensively bound to plasma proteins: approximately 97–99% bound, primarily to sex hormone-binding globulin (SHBG, about 40%) and albumin (about 60%). Only 1–3% is free (unbound) and biologically active. |
| Volume of Distribution | The apparent volume of distribution (Vd) of testosterone is approximately 1.0 L/kg, indicating distribution into total body water and extensive tissue binding, particularly to muscle, skin, and prostate. |
| Bioavailability | Transdermal bioavailability of testosterone from Testoderm TTS is approximately 15–25% of the applied dose, due to incomplete absorption and first-pass cutaneous metabolism. The patch delivers 2.5–5 mg of testosterone per day depending on patch size. |
| Onset of Action | Following transdermal application of Testoderm TTS, serum testosterone concentrations reach therapeutic levels within 2–4 hours, with steady-state achieved after 2–3 days of daily dosing. |
| Duration of Action | The duration of action is approximately 24 hours, requiring once-daily application. Serum testosterone levels remain within the normal range for the dosing interval, but decline to baseline within 24 hours after patch removal. |
Apply 4 mg (one 4 mg/24 hr system) or 6 mg (one 6 mg/24 hr system) transdermally once daily, applied to clean, dry, intact skin on the back, abdomen, thighs, or upper arms. Rotate application sites with an interval of at least 7 days.
| Dosage form | FILM, EXTENDED RELEASE |
| Renal impairment | No dosage adjustment required for mild to moderate renal impairment. Use with caution in severe renal impairment (GFR <30 mL/min) due to potential for accumulation of excipients; monitor testosterone levels. |
| Liver impairment | Contraindicated in patients with severe hepatic impairment (Child-Pugh class C). For mild to moderate impairment (Child-Pugh A or B), use with caution and monitor liver function and testosterone levels; no specific dose modification established. |
| Pediatric use | Not indicated for use in pediatric patients (safety and efficacy not established). Androgen replacement therapy is typically initiated only in adolescent males with confirmed hypogonadism under specialist supervision; weight-based dosing not recommended. |
| Geriatric use | Use with caution in elderly patients due to increased risk of prostatic hyperplasia and prostatic carcinoma. Monitor prostate-specific antigen (PSA) and hematocrit. Initiate at lowest effective dose (e.g., 4 mg/day) and titrate based on serum testosterone levels. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for TESTODERM TTS (TESTODERM TTS).
| Breastfeeding | Testosterone is excreted in breast milk. The M/P ratio is unknown. Testosterone may suppress lactation and cause virilization in the nursing infant. Use during breastfeeding is contraindicated. |
| Teratogenic Risk | Testosterone is contraindicated in pregnancy. Exposure during the first trimester is associated with virilization of the female fetus, including clitoromegaly and labial fusion. Second and third trimester exposure may cause pseudohermaphroditism in female fetuses. Androgens can cross the placenta and disrupt normal sexual differentiation. |
■ FDA Black Box Warning
WARNING: SECONDARY EXPOSURE TO TESTOSTERONE. Testosterone can be transferred to others through direct skin contact, leading to adverse effects in children and women. Patients should wash hands after application, cover application site with clothing, and wash skin before direct contact with others.
| Serious Effects |
["Breast cancer or known or suspected prostate cancer in males","Pregnancy or breastfeeding (women)","Hypersensitivity to testosterone or any component of the product","Men with breast cancer"]
| Precautions | ["Secondary exposure risk and virilization in children and women","Polycythemia - increased risk of cardiovascular events","Prostate cancer and benign prostatic hyperplasia (BPH) exacerbation","Hepatic adverse effects including cholestatic hepatitis and jaundice","Edema in patients with preexisting cardiac, renal, or hepatic disease","Lipid profile changes (decreased HDL)"] |
Loading safety data…
| Fetal Monitoring |
| Monitoring includes maternal serum testosterone levels (target within physiological range for pregnancy if used for specific conditions), fetal ultrasound for signs of virilization (ambiguous genitalia), and assessment of maternal adverse effects such as hirsutism, acne, and voice changes. |
| Fertility Effects | Testosterone suppresses endogenous gonadotropin secretion, which can impair spermatogenesis in males. In females, supraphysiological doses may disrupt menstrual cycles and reduce fertility. These effects are generally reversible upon discontinuation. |