Beta-blockers have some clinical use in the treatment of angina pectoris, hypertension, and tachycardia. In addition, they have been used to control migraine, chronic alcoholism, schizophrenia, essential tremor, and cardiac effects of cocaine overdose. Unfortunately, misuse of these drugs as doping agents in archery, billiards, and riflery competitions happens from time to time where 5- to 100-mg oral doses are typical to decrease the heart rate and muscular tremor (1 ,2 ).