Bromocriptine reduces cigarette smoking

Aims. Animal studies have shown that nicotine releases dopamine, a neurotra nsmitter implicated in drug reinforcement. We hypothesized that bromocripti ne would decrease smoking behavior in humans. Design. The study was conduct ed double blind and subjects' order of dose exposure was randomized. Partic ipants. The smoking behavior of 20 heavy smokers was recorded for 5 hours a fter ingesting placebo or one of two doses of bromocriptine (2.50 mg, 3.75 mg) over three sessions (one dose per session). Findings. There was a signi ficant negative linear trend by dosage indicating shorter total puffing tim e with increasing bromocriptine dosages (p < 0.02). Other significant negat ive linear trends by increasing dosage include fewer number of puffs, fewer number of cigarettes smoked and mean latency to smoke after 3 hours (expec ted C-MAX on the drug (all ps < 0.05). There was a negative significant lin ear trend showing decreased plasma nicotine (p < 0.02) and cotinine (p < 0. 005) with increasing dosages of bromocriptine. Shiffman/Jarvik Withdrawal S cale (SJWS) cigarette craving subscale scores decreased significantly acros s increasing dosages (linear trend p < 0.02). There was a significant negat ive linear trend (p < 0.05) on the Profile of Mood States (POMS) Vigor and Depression subscales, with subjects reporting decreased vigor and depressio n with increasing bromocriptine doses. No other mood effects were observed. Conclusion. These results support the hypothesis that dopaminergic mechani sms mediate cigarette smoking reinforcement.