special subjects
Anabolic Steroids
Pathophysiology Caused by Anabolic Steroids
Anabolic steroids have androgenic effects (eg, changes in hair or in libido, aggressiveness) and anabolic effects (eg, increased protein utilization, increased muscle mass). Androgenic effects cannot be separated from the anabolic, but some anabolic steroids have been synthesized to minimize the androgenic effects. There is limited acute toxicity with a single dose. Adverse effects of anabolic steroids vary significantly by dose and drug. There are few adverse effects at physiologic replacement doses (eg,methyltestosterone10 to 50 mg/day or its equivalent). Athletes may use doses 10 to 50 times this range. At high doses, some effects are clear; others are equivocal (see table). Uncertainties exist because most studies involve abusers who may not report doses accurately and who also use black market drugs, many of which are counterfeit and contain (despite labeling) varying doses and substances. Athletes may take a fixed dose of one or multiple kinds of steroids for a certain period, stop, then start again (cycling) several times a year. Intermittently stopping the drugs is believed to allow endogenoustestosteronelevels, sperm count, and the hypothalamic-pituitary-gonadal axis to return to normal. Anecdotal evidence suggests that cycling may decrease harmful effects and the need for increasing drug doses to attain the desired effect. Athletes frequently use multiple kinds of anabolic steroids simultaneously (a practice called stacking). They may use different routes of administration (oral, IM, or transdermal) simultaneously. Starting from a small dose and increasing the dose gradually, and tapering the dose of the same anabolic steroid to zero is referred to as pyramiding. Stacking and pyramiding are intended to increase receptor binding and minimize adverse effects, but these benefits have not been proved. To avoid positive anti-doping tests, athletes may stop using long-lasting steroids and replace them with shorter-acting formulations (bridging). 