A comparison of bupropion hydrochloride with dexamphetamine and amitriptyline in healthy subjects.

The effects of bupropion, a potential antidepressant drug, has been investigated in twelve healthy subjects, (six men and six women) in a double-blind controlled, balanced study, and compared with dexamphetamine and amitriptyline. Analysis of variance was used to assess significance of differences with < 0.05 taken as significant. Bupropion 50 and 100 mg (HCl) failed to differ from lactose on any of the measures of performance tested. By contrast amitriptyline 25 mg (base) impaired auditory vigilance, tapping rate, and short term memory and prolonged auditory reaction time. Dexamphetamine 10 mg improved auditory vigilance and tapping rates and dexamphetamine 5 mg produced similar trends. Bupropion did not differ from lactose on heart rate, pupil size and salivary secretion. Amitriptyline produced miosis and dexamphetamine 10 mg mydriasis and increased heart rate. Dexamphetamine 10 mg increased systolic blood pressure (BP) when taken erect and supine. Supine systolic BP was increased, compared with lactose, after all treatments except bupropion 50 mg, possibly due to a spuriously low mean after lactose. These changes were not seen when standing and no changes ascribable to treatments were recorded in diastolic BP. No changes in the electroencephalogram (EEG) occurred after bupropion or dexamphetamine. Amitriptyline increased activity in the delta band (2.3-4 Hz) and decreased in the alpha band (7.5-13.5 Hz). Bupropion produced no changes in subjective ratings measured with visual analogue scales. Amitriptyline produced drowsiness, sedation and physical impairment, whereas dexamphetamine increased alertness and produced elation and increased sociability. No side effects could be ascribed to bupropion with any certainty. It was concluded that bupropion differs in its pharmacodynamic properties from both dexamphetamine and amitriptyline. At the doses examined the drug is devoid of stimulant and sedative properties. In addition, no cardiovascular or anticholinergic effects occurred and in view of these potential advantages over available antidepressant drugs, further clinical studies are in progress.