Patient Understanding of the Neuropsychiatric Risks Associated with Branded Bupropion Hydrochloride Products Used for Smoking Cessation.

BACKGROUND: Bupropion hydrochloride (Zyban) is an effective aid to smoking cessation; however, its use has previously been associated with neuropsychiatric adverse events. Here we report results of the patient Knowledge, Attitudes, and Behavior survey that forms part of the Year 7 Risk Evaluation and Mitigation Strategy (REMS) assessment for Zyban. OBJECTIVE: Assess participants' understanding of the neuropsychiatric risks associated with branded bupropion hydrochloride products that are used for smoking cessation, as described in the Medication Guides. METHODS: A cross-sectional study was conducted among patients ≥ 18 years of age, who had used or filled a prescription for branded bupropion hydrochloride for smoking cessation in the past 6 months. Participants were recruited through an online panel, pharmacy network, or by healthcare provider referral, and invited to complete a survey containing questions regarding the risks associated with the use of branded bupropion hydrochloride products, and whether they had received and read the Medication Guide. The study aimed for ≥ 80% of participants to respond correctly to each question regarding neuropsychiatric risks. RESULTS: From the 50,985 survey invitations distributed, 1017 participants responded, of whom 144 were eligible and 142 completed the survey. Over 80% of participants correctly responded to most neuropsychiatric risk questions. Approximately three-quarters of participants received the Medication Guide when they last filled their prescription, of whom over half read the Medication Guide at that time. CONCLUSIONS: Participants enrolled in this Year 7 REMS survey had good understanding of the neuropsychiatric risks associated with using branded bupropion hydrochloride products for smoking cessation.

Cardiovascular adverse events in the drug-development program of bupropion for smoking cessation: A systematic retrospective adjudication effort.

BACKGROUND: In 2011, the US Food and Drug Administration requested that GlaxoSmithKline perform retrospective adjudication of cardiovascular (CV) events reported in the bupropion drug-development trials for smoking cessation. HYPOTHESIS: Retrospective adjudication of clinical trial data will not increase the identification of adverse events. METHODS: We performed a comprehensive retrospective analysis of adverse events in 19 previously completed controlled US clinical trials of bupropion marketed for the treatment of smoking cessation, yielding 9479 subjects (5290 bupropion, 2927 placebo, 1018 active control [ACT], and 244 treated concurrently with bupropion and ACT). All adverse events were sent to the Duke Clinical Research Institute for adjudication by Clinical Events Classification (CEC) physician reviewers. The primary endpoint was a composite of major adverse CV events: CV death, nonfatal myocardial infarction (MI), and nonfatal stroke. RESULTS: Overall, 416 nonfatal CV events in 366 subjects, and 22 deaths, were identified and processed for adjudication. Of these, 7 nonfatal MIs (4 bupropion, 3 placebo, 0 ACT), 5 nonfatal strokes (1 bupropion, 3 placebo, 1 ACT), and 9 CV deaths (4 bupropion, 4 placebo, 1 ACT) were confirmed by the CEC Committee. The primary endpoint occurred in 3/4297 (0.07%) subjects in the bupropion group and in 4/2927 (0.14%) subjects in the placebo group (log-rank P value: 0.613). CONCLUSIONS: CV events in bupropion clinical trials for smoking cessation were uncommon, with no observed increase among subjects assigned to bupropion vs placebo. However, this effort was limited by a paucity of quality data.

Neuropsychiatric safety and efficacy of varenicline, bupropion, and nicotine patch in smokers with and without psychiatric disorders (EAGLES): a double-blind, randomised, placebo-controlled clinical trial.

BACKGROUND: Substantial concerns have been raised about the neuropsychiatric safety of the smoking cessation medications varenicline and bupropion. Their efficacy relative to nicotine patch largely relies on indirect comparisons, and there is limited information on safety and efficacy in smokers with psychiatric disorders. We compared the relative neuropsychiatric safety risk and efficacy of varenicline and bupropion with nicotine patch and placebo in smokers with and without psychiatric disorders. METHODS: We did a randomised, double-blind, triple-dummy, placebo-controlled and active-controlled (nicotine patch; 21 mg per day with taper) trial of varenicline (1 mg twice a day) and bupropion (150 mg twice a day) for 12 weeks with 12-week non-treatment follow-up done at 140 centres (clinical trial centres, academic centres, and outpatient clinics) in 16 countries between Nov 30, 2011, and Jan 13, 2015. Participants were motivated-to-quit smokers with and without psychiatric disorders who received brief cessation counselling at each visit. Randomisation was computer generated (1:1:1:1 ratio). Participants, investigators, and research personnel were masked to treatment assignments. The primary endpoint was the incidence of a composite measure of moderate and severe neuropsychiatric adverse events. The main efficacy endpoint was biochemically confirmed continuous abstinence for weeks 9-12. All participants randomly assigned were included in the efficacy analysis and those who received treatment were included in the safety analysis. The trial is registered at ClinicalTrials.gov (number NCT01456936) and is now closed. FINDINGS: 8144 participants were randomly assigned, 4116 to the psychiatric cohort (4074 included in the safety analysis) and 4028 to the non-psychiatric cohort (3984 included in the safety analysis). In the non-psychiatric cohort, 13 (1·3%) of 990 participants reported moderate and severe neuropsychiatric adverse events in the varenicline group, 22 (2·2%) of 989 in the bupropion group, 25 (2·5%) of 1006 in the nicotine patch group, and 24 (2·4%) of 999 in the placebo group. The varenicline-placebo and bupropion-placebo risk differences (RDs) for moderate and severe neuropsychiatric adverse events were -1·28 (95% CI -2·40 to -0·15) and -0·08 (-1·37 to 1·21), respectively; the RDs for comparisons with nicotine patch were -1·07 (-2·21 to 0·08) and 0·13 (-1·19 to 1·45), respectively. In the psychiatric cohort, moderate and severe neuropsychiatric adverse events were reported in 67 (6·5%) of 1026 participants in the varenicline group, 68 (6·7%) of 1017 in the bupropion group, 53 (5·2%) of 1016 in the nicotine patch group, and 50 (4·9%) of 1015 in the placebo group. The varenicline-placebo and bupropion-placebo RDs were 1·59 (95% CI -0·42 to 3·59) and 1·78 (-0·24 to 3·81), respectively; the RDs versus nicotine patch were 1·22 (-0·81 to 3·25) and 1·42 (-0·63 to 3·46), respectively. Varenicline-treated participants achieved higher abstinence rates than those on placebo (odds ratio [OR] 3·61, 95% CI 3·07 to 4·24), nicotine patch (1·68, 1·46 to 1·93), and bupropion (1·75, 1·52 to 2·01). Those on bupropion and nicotine patch achieved higher abstinence rates than those on placebo (OR 2·07 [1·75 to 2·45] and 2·15 [1·82 to 2·54], respectively). Across cohorts, the most frequent adverse events by treatment group were nausea (varenicline, 25% [511 of 2016 participants]), insomnia (bupropion, 12% [245 of 2006 participants]), abnormal dreams (nicotine patch, 12% [251 of 2022 participants]), and headache (placebo, 10% [199 of 2014 participants]). Efficacy treatment comparison did not differ by cohort. INTERPRETATION: The study did not show a significant increase in neuropsychiatric adverse events attributable to varenicline or bupropion relative to nicotine patch or placebo. Varenicline was more effective than placebo, nicotine patch, and bupropion in helping smokers achieve abstinence, whereas bupropion and nicotine patch were more effective than placebo. FUNDING: Pfizer and GlaxoSmithKline.

Dose-related reduction in bupropion plasma concentrations by ritonavir.

The effect of repeat oral doses of ritonavir, at high (600 mg twice daily) and low (100 mg twice daily) doses, on the pharmacokinetics of a single dose of bupropion was evaluated in healthy volunteers. Subjects received a single dose of 150 mg of bupropion on day 1 and twice-daily ritonavir from day 8 through day 30. Ritonavir was up-titrated from 300 mg twice daily to 600 mg twice daily in the high-dose ritonavir study, whereas subjects remained on 100 mg twice-daily ritonavir in low-dose ritonavir study. Subjects received a second single dose of bupropion on day 24. Serial blood samples were obtained to evaluate the pharmacokinetics of bupropion and its metabolites on days 1 and 24. Steady-state ritonavir led to a decrease of area under the curve and maximum plasma concentration of bupropion by 62% to 67% in the high-dose study and by 21% to 22% in the low-dose study, indicating a drug interaction of statistical and clinical significance, particularly at high doses of ritonavir. These studies demonstrate that the reduction of bupropion exposure by ritonavir is dose-related. Dosage adjustment of bupropion may be needed when administered with ritonavir. However, the maximum recommended daily dose of bupropion should not be exceeded.

In vivo activity of bupropion at the human dopamine transporter as measured by positron emission tomography.

BACKGROUND: Converging lines of evidence are consistent with an inhibitory effect of the antidepressant and smoking-cessation aid bupropion on dopamine and norepinephrine reuptake, but the in vivo effects of the drug at the human dopamine transporter (DAT) have not been studied to date. This study employed positron emission tomography (PET) to assess the extent and duration of DAT receptor occupancy by bupropion and its metabolites under conditions of steady-state oral dosing with bupropion sustained-release (SR) in healthy volunteers. METHODS: Six healthy male volunteers received bupropion SR 150 mg daily on days 1 through 3 and 150 mg every 12 hours on day 4 through the morning of day 11. PET investigations were performed between 1 and 7 days before initiation of bupropion SR dosing, as well as 3, 12, and 24 hours after the last dose of bupropion SR on day 11. RESULTS: Bupropion and its metabolites inhibited striatal uptake of the selective DAT-binding radioligand (11)C-betaCIT-FE in vivo. Three hours after the last dose of bupropion SR, average DAT occupancy by bupropion and its metabolites was 26%-a level that was maintained through the last PET assessment at 24 hours after dosing. CONCLUSIONS: Bupropion and its metabolites induced a low occupancy of the striatal DAT over 24 hours under conditions of steady-state oral dosing with therapeutic doses of bupropion SR. These data are consistent with the hypothesis that dopamine reuptake inhibition may be responsible in part for the therapeutic effects of the drug.

Pharmacokinetic optimisation of sustained-release bupropion for smoking cessation.

Sustained-release bupropion (bupropion SR) is a unique, non-nicotine smoking cessation aid that is hypothesised to act upon neurological pathways involved in nicotine dependence. Pharmacokinetic and metabolism studies reveal that bupropion SR is metabolised by multiple pathways with no single pathway predominating. When one pathway is inhibited, others are available to compensate. Therefore, only a few clinically relevant drug-drug interactions involving bupropion SR have been observed, although the potential for interactions exists, as with any extensively metabolised drug. Population pharmacokinetic/pharmacodynamic analyses of data from patients receiving daily oral doses of 100mg, 150mg, or 300mg reveal that the anti-smoking efficacy of bupropion SR is directly related to dose. The incidences of dry mouth and insomnia were directly related to bupropion plasma concentrations while the incidence of anxiety was inversely proportional to bupropion plasma concentrations. To maximise efficacy (with an acceptable safety profile), the optimal daily dose for the majority of patients is 300mg.

Impact of prior nicotine replacement therapy on smoking cessation efficacy.

OBJECTIVE: To examine previous use of nicotine replacement therapy (NRT) on the smoking-cessation efficacy of bupropion sustained release (SR). METHODS: Secondary analysis of a parallel-group, randomized, double-blind, placebo-controlled study. Smokers who had, based on self-report, no previous history of NRT (N = 453) or who had used NRT at least once (N = 440) were randomized to receive placebo, bupropion SR, nicotine transdermal system (NTS), or a combination of bupropion SR and NTS. RESULTS: Bupropion SR showed similar efficacy in participants with or without previous use of NRT. CONCLUSION: Bupropion SR is effective in promoting smoking abstinence regardless of prior NRT use.

Continuation phase treatment with bupropion SR effectively decreases the risk for relapse of depression.

BACKGROUND: This was the first controlled continuation phase study (up to 1-year total treatment) to evaluate the safety and efficacy of bupropion SR for decreasing the risk for relapse of depression in patients who responded to bupropion SR. METHODS: Patients with recurrent major depression were treated with bupropion SR 300 mg/day during an 8-week open-label phase. Responders (based on Clinical Global Impressions Scale for Improvement of Illness scores) entered a randomized, double-blind phase where they received bupropion SR 300 mg/day or placebo for up to 44 weeks. After randomization, relapse was defined as the point at which the investigator intervened by withdrawing the patient from the study to treat depression. RESULTS: Four hundred twenty-three patients were randomized. A statistically significant difference in favor of bupropion SR over placebo was seen in the time to treatment intervention for depression when survival curves were compared (log-rank test, p =.003). Statistically significant separation between bupropion SR and placebo began at double-blind week 12 (p <.05). Adverse events in bupropion SR-treated patients accounted for 9% and 4% of discontinuations from the open-label and double-blind phases, respectively. CONCLUSIONS: Bupropion SR was shown to be effective and well tolerated in decreasing the risk for relapse of depression for up to 44 weeks.