To compare bupropion to placebo for reducing methamphetamine (MA) use, increasing
retention, and reducing the severity of depressive symptoms and MA-cravings. A secondary
objective compared bupropion to placebo for reducing cigarette smoking among MA dependent
participants.
Following a 2-week, non-medication baseline screening period, 73 treatment-seeking
MA dependent participants were randomly assigned to bupropion sustained release (150
mg twice daily; N=36) or placebo (twice daily; N=37) for 12-weeks under double-blind
conditions. Participants attended clinic thrice weekly to provide urine samples analyzed
for MA-metabolite, to complete research measures and assessments, and to receive contingency
management and weekly cognitive behavioral therapy sessions.
There were no statistically significant effects for bupropion relative to placebo
on MA use verified by urine drug screens, for reducing the severity of depressive
symptoms or MA-cravings, or on study retention. In a post hoc analysis, there was
a statistically significant effect of bupropion treatment on MA use among participants
with lighter (0-2 MA-positive urines), but not heavier (3-6 MA-positive urines) MA
use during baseline (OR=2.81, 95% CI=1.61-4.93, p<0.001 for MA-free week with bupropion
among light users). Bupropion treatment was also associated with significantly reduced
cigarette smoking, by almost five cigarettes per day (p=0.0002).
Bupropion was no more effective than placebo in reducing MA use in planned analyses,
though bupropion did reduce cigarette smoking. Post hoc findings of an effect for
bupropion among baseline light, but not heavy, MA users suggests further evaluation
of bupropion for light-MA users is warranted.