Behavioral and cardiovascular effects of intravenous methylphenidate in normal subjects and cocaine abusers

This study compares the behavioral and cardiovascular response to methylphenidate (0.5 mg i.v.) in 10 cocaine abusers and 20 controls. Methylphenidate induced a long-lasting increase in blood pressure and pulse rate in both groups of subjects. It also induced a short-lasting 'high' (27 min) and longer-lasting 'restlessness' (67 min). In the normal subjects, but not in the cocaine abusers, methylphenidate significantly increased sexual desire and induced a subjective experience of 'loss of control'. In the cocaine abusers, methylphenidate consistently induced cocaine craving. While 90% of the cocaine abusers reported methylphenidate as pleasurable, only 50%, of the normal subjects did. Cocaine abusers reported that the 'high' induced by methylphenidate was similar to that of cocaine but lasted longer and was associated with more physical effects.