PHARMACOLOGY AND TOXICOLOGY

Mode of action

Toxicodynamics The toxic effects are an exaggeration of the normal pharmacological effects.

Pharmacodynamics

Anabolic steroids bind to specific receptors present especially in reproductive tissue, muscle and fat (Mooradian & Morley, 1987). The anabolic steroids reduce nitrogen excretion from tissue breakdown in androgen deficient men. They are also responsible for normal male sexual differentiation. The ratio of anabolic ("body-building") effects to androgenic (virilizing) effects may differ among the members of the class, but in practice all agents possess both properties to some degree. There is no clear evidence that anabolic steroids enhance overall athletic performance (Elashoff et al, 1991).


Carcinogenicity

Anabolic steroids may be carcinogenic. They can stimulate growth of sex-hormone dependent tissue, primarily the prostate gland in men. Precocious prostatic cancer has been described after long-term anabolic steroid abuse (Roberts & Essenhigh, 1986). Cases where hepatic cancers have been associated with anabolic steroid abuse have been reported (Overly et al, 1984).

Teratogenicity

Androgen ingestion by a pregnant mother can cause virilization of a female fetus (Dewhurst & Gordon, 1984).



Main adverse effects

The adverse effects of anabolic steroids include weight gain, fluid retention, and abnormal liver function as measured by biochemical tests. Administration to children can cause premature closure of the epiphyses. Men can develop impotence and azoospermia. Women are at risk of virilization.