Psychological and physiological effects of bupropion compared to methylphenidate after prolonged administration in healthy volunteers (NCT00285155).

Purpose: Bupropion is largely used as an antidepressant and smoking cessation therapy. The aim of this work was to compare pharmacodynamic properties of bupropion and the amphetamine-like methylphenidate after sustained administration in humans.

Methods: Twelve male volunteers completed this randomized, double-blind, placebo controlled, cross-over study. Bupropion and methylphenidate were administered separately for initial half-dose 6-day periods (150 and 10 mg respectively) followed by full-dose 8-day periods (300 and 20 mg respectively). Outcomes were subjective feelings, cognitive performances, autonomic and physiological parameters.

Results: Data are expressed as mean(SEM). After repeated administration, bupropion, like methylphenidate, decreased asthenia-fatigue [44(3.2) and 42(3.7), respectively vs. 53(4.1) for placebo; p = 0.034], despite an impairment of sleep onset [-4.3(3.32) and -1.9(3.76), respectively vs. +7.5(3.69); p = 0.016]. Both drugs increased resting diastolic blood pressure [67.9(1.23) and 65.7(0.98), respectively vs. 62.5(1.42) mm Hg; p = 0.001], body temperature [36.5(0.12) and 36.5(0.14) vs. 36.3(0.10) °C; p = 0.037] and decreased body weight [-0.7(0.23) and -0.6(0.22), respectively vs. +0.2(0.27) kg; p = 0.038]. No significant change could be observed on cognitive functions, appetite and energy consumption.

Conclusion: Although it may not share all the properties of stimulant drugs, the effect profile of bupropion presents a number of similarities with that of methylphenidate over a 2-week treatment period.