The effects of testosterone in humans and other vertebrates occur by way of two main mechanisms: by activation of the androgen receptor (directly or as DHT), and by conversion to estradiol and activation of certain estrogen receptors. Free testosterone (T) is transported into the cytoplasm of target tissue cells, where it can bind to the androgen receptor, or can be reduced to 5α-dihydrotestosterone (DHT) by the cytoplasmic enzyme 5α-reductase. DHT binds to the same androgen receptor even more strongly than T, so that its androgenic potency is about 2.5 times that of T. The T-receptor or DHT-receptor complex undergoes a structural change that allows it to move into the cell nucleus and bind directly to specific nucleotide sequences of the chromosomal DNA. The areas of binding are called hormone response elements (HREs), and influence transcriptional activity of certain genes, producing the androgen effects.
Androcap Capsule 40 mg
Inoperable metastatic breast cancer:
Adult: As enanthate: 200-400 mg every 2-4 wk.
Adult: 50-400 mg every 2-4 wk for the cipionate; 50-400 mg every 2-4 wk for the enantate (or an initial dose of 250 mg every 2-3 wk followed by a maintenance dose every 3-6 wk); up to 50 mg 2-3 times wkly for the propionate.
Adult: Initially, 120-160 mg daily of the undecylate ester followed by a maintenance dose of 40-120 mg daily.
Adult: As SC implant: 100-600 mg. A dose of 600 mg is usually able to maintain plasma testosterone level within physiological range for 4-5 mth.
Adult: As patch delivering 2.5-7.5 mg daily: Apply to the back, abdomen, thighs, upper arms as directed. As scrotal patch containing 10 or 15 mg (supplying 4-6 mg in 24 hr): Use as directed.
Adult: 30 mg bid.