Androgens and antiandrogens (Pharmacology)

Androgens used in therapy
Androgens used in therapy are substances that have effects similar to physiologically produced hormones.

Indications

 * Hypogonadism;
 * Improving the condition of the organism (it is possible to indicate them to patients in whom it is necessary to support anabolic pathways - patients with AIDS, osteoporosis, previously also with anemias);
 * Breast cancer (in post-menopausal women);
 * Misuse as anabolics in athletes.

Medicaments and methods of administration

 * Testosterone: The basic remedy is testosterone. When administered orally (p.o.), it has a high first pass effect, thus it must be administered by other ways. It is applied transdermally in the form of gels' or patches' - these are able to maintain testosterone levels for up to a week.
 * Testosterone esters: Testosterone can also be administered in the form of esters. These can also be administered p.o. as due to their high lipophilicity they travel with other lipids through the lymph after absorption and bypass the high first pass effect of the liver. Another option is intramuscular (i.m.) administration. The registered representative is testosterone undecanoate (for p.o. and i.m. administration).
 * Anabolic steroids: Anabolic steroids have enhanced anabolic effects and suppressed androgenic effects. The representatives are mesterolone (for p.o. administration) and nandrolone (with injectable administration).

Side effects
Side effects are based on the physiological effects of androgens. They mainly include: Some side effects are exacerbated with anabolic steroids, most notably hepatotoxicity, testicular atrophy, personality disorders associated with an increase in aggression, and the risk of increased IHD and sudden cardiac death.
 * Puberty-like symptoms - administration before puberty stops growth;
 * Gynecomastia;
 * Increased sodium and water retention;
 * Reduced physiological testicular function resulting in decreased spermatogenesis, which can lead to infertility - the condition is reversible;
 * Virilisation in women.

Antiandrogens
Antiandrogens are pharmaceuticals that reduce the effect of androgens. This group includes androgen receptor antagonists and 5α-reductase blockers.

Androgen receptor antagonists
Drugs from this group are used in the therapy of prostate cancer in combination with gonadoliberin analogues.

Side effects are considerable and include, in particular:
 * Hot flashes, gynecomastia, mastodynia;
 * Diarrhea, nausea, vomiting;
 * Impotence;
 * Depression, fatigue, malaise;
 * Hepatotoxicity.

Representatives of androgen receptor antagonists

 * Cyproterone - a steroidal partial androgen receptor agonist and progestin.
 * Flutamide and Bicalutamide - non-steroidal antagonists.

5α-reductase inhibitors
5α-reductase inhibitors inhibit the metabolism of testosterone to dihydrotestosterone. Representatives are dutasteride and finasteride. They are used to treat benign prostatic hyperplasia or, for example, androgenetic alopecia (finasteride).

Related articles

 * Testosterone
 * Steroid hormones synthesis