Bupropion is an antidepressant agent that is also effective as an aid to quit cigarette smoking. A single 150-mg tablet of sustained-release bupropion hydrochloride was administered to two groups of volunteers, cigarette smokers and nonsmokers, who were matched for race, gender, body frame, age, and weight. Pharmacokinetic parameters were calculated for bupropion, and three major metabolites (hydroxybupropion and the aminoalcohol isomers, threohydrobupropion and erythrohydrobupropion, expressed as a composite total). Mean (+/-SD) values of area under the concentration-time curve from time 0 extrapolated to infinity (AUC0-infinity), maximum concentration (Cmax), time to reach Cmax (tmax), and half-life (t1/2) of bupropion in smokers and nonsmokers, respectively, were 1,164 +/- 220 ng.hr/mL and 1,161 +/- 292 ng.hr/mL; 144 +/- 28 ng/mL and 143 +/- 39 ng/mL; 3.00 +/- 0.50 hours and 2.88 +/- 0.49 hours; and 19 +/- 5 hours and 18 +/- 3 hours. No clinically significant differences between smokers and nonsmokers or between male and female volunteers were observed for the pharmacokinetics of bupropion or its metabolites. The absence of pharmacokinetic differences indicates that dosage adjustments are not necessary when bupropion is prescribed to male and female cigarette smokers.

Despite the high prevalence of sexual desire disorders, little is known about their biological underpinnings in humans. Animal studies suggest that dopamine is involved in appetitive sexual behavior; thus, one aim of this study was to elucidate that relationship in humans. This study used measurement of the acoustic startle response (ASR) and prepulse inhibition of the startle response (PPI) as psychophysiological indicators of changes in motivational states to assess the potential relation between sexual desire and appetitive motivation in humans. Responses to sexually provocative stimuli consisting of single nude men and single nude women in a sample of 153 participants (77 men, 76 women) were assessed. The results indicated that ASR was attenuated after exposure to appetitive stimuli (i.e., sexually provocative pictures of attractive individuals) to a greater extent among participants with higher levels of sexual desire, as measured by the Sexual Desire Inventory-2 (Spector, I. P., Carey, M. P., & Steinberg, L. (1996). Journal of Sex & Marital Therapy, 22, 175-190). In addition, PPI was inversely associated with subjective ratings across stimuli such that greater subjective levels of desire were correlated with lower levels of PPI. In general, these results suggest that individuals with lower levels of sexual desire may have a diminished physiological response to appetitive sexual stimuli.