Bupropion XL and SR have similar effectiveness and adverse event profiles when used to treat smoking among patients at a comprehensive cancer center.

Background And Objectives: Bupropion extended-release (XL; once-daily dosing) has equal efficacy with the sustained-release (SR) formulation (twice-daily dosing) for treating depression, but no studies have compared the two formulations for the treatment of smoking. In a naturalistic open-label study, we compared the effectiveness and the adverse event profiles of XL and SR in treating cancer patients for smoking.

Methods: Cancer patients (N = 648) were prescribed bupropion XL (n = 454) or SR (n = 194) alone or in combination with nicotine replacement therapy (NRT) for treating smoking from September 2006 to December 2017. We analyzed 7-day point prevalence abstinence at end-of-treatment (EOT; 3 months postmedication initiation) and evaluated for noninferiority. We also analyzed the adverse event profile differences between the medications.

Results: There were no significant differences in abstinent rates at EOT between bupropion XL and SR when using intent-to-treat models, regardless of concomitant NRT. XL demonstrated noninferiority in treatment efficacy compared to SR when excluding those on combined treatment with NRT. Further, there were no significant differences in spontaneously reported adverse events between XL and SR.

Conclusions: Our data did not reveal a difference between bupropion XL and SR formulations in terms of effectiveness or adverse event profiles among cancer patients prescribed bupropion alone or in combination with NRTs to quit smoking.

Scientific Significance: In this first published direct comparison of their effectiveness and adverse event profiles, we found that bupropion XL is likely therapeutically equivalent to bupropion SR when treating smoking among cancer patients, and produces similar side effects.