Testosterone is the primary endogenous androgen, a steroid hormone synthesized from cholesterol in the Leydig cells of the testes (95%), and to a lesser extent in the adrenal cortex and ovaries. In the Indian context, its therapeutic use is primarily for the treatment of male hypogonadism, a condition with increasing recognition and diagnosis. The 25mg strength is a common oral formulation, though it has significant first-pass metabolism. It acts by binding to and activating the androgen receptor, influencing the development and maintenance of male sexual characteristics, muscle mass, bone density, erythropoiesis, and mood.
Adult: For hypogonadism: Testosterone undecanoate 40-80 mg orally twice daily with meals (equivalent to unesterified testosterone varies; 25mg unesterified T is not a standard oral dose). A common regimen is 40 mg (one capsule) 2-3 times daily. Dose MUST be individualized based on serum testosterone levels, clinical response, and tolerability.
Note: Must be taken WITH FOOD, preferably a meal containing fats (20-30g), to enhance lymphatic absorption and bioavailability. Capsules should be swallowed whole, not crushed or chewed. Doses should be evenly spaced (e.g., morning and evening). Regular monitoring of serum testosterone (trough level before morning dose) is crucial.
Testosterone is the principal male sex hormone. Its action is mediated through binding to a specific nuclear androgen receptor (AR) in target tissues. The hormone-receptor complex undergoes dimerization, translocates to the nucleus, binds to androgen response elements (AREs) on DNA, and regulates the transcription of specific genes. This leads to the synthesis of proteins responsible for the androgenic and anabolic effects.
Pregnancy: CATEGORY X. Contraindicated. May cause virilization of the external genitalia of the female fetus. Androgens are not indicated for use in women.
Driving: No direct effect, but patients should be cautioned about potential dizziness, headache, or mood changes that could impair ability to drive or operate machinery.
| Warfarin and other Anticoagulants | Testosterone may increase anticoagulant effect by reducing clotting factor synthesis and increasing fibrinolysis. Increased risk of bleeding. | Major |
| Corticosteroids (e.g., Prednisolone) | Increased risk of severe edema due to synergistic sodium and water retention. | Major |
| Insulin and Oral Hypoglycemics | Testosterone may alter insulin sensitivity; blood glucose monitoring required as dose of antidiabetic may need adjustment. | Moderate |
| Cyclosporine, Tacrolimus | Testosterone may inhibit CYP3A4, potentially increasing levels of these immunosuppressants and risk of toxicity. | Moderate |
| Propranolol | Testosterone may increase clearance of propranolol, reducing its effect. | Moderate |
| Oxyphenbutazone | May increase serum levels of testosterone. | Minor |