Study of monotherapy versus combination therapy for tobacco dependence among heavily addicted smokers.

OBJECTIVES: Combination therapy for tobacco dependence is becoming a standard of care. We sought to compare benefits and adverse events for combination therapy versus monotherapy for smokers in The Smokers' Health Project.

METHODS: This secondary data analysis was derived from adult smokers (n = 198) who initially smoked 15 or more cigarettes per day and participated in The Smokers' Health Project. Participants were grouped as taking 1 medication or 2 concurrent medications for tobacco dependence for 1 year over the 2-year study period. Adverse events were compared between medication groups using chi-square tests. Crude and adjusted odds ratios were calculated for cessation at 6, 12, 18, and 24 months using logistic regression.

RESULTS: No differences were seen in the proportion of incident adverse events between the monotherapy (28.3%) and combination therapy (32.3%) groups (P = 0.54). At 6 months, the odds of quitting were less in the combination therapy group relative to those taking monotherapy (adjusted odds ratio = 0.47 [95% CI 0.24-0.93]). At 12, 18, and 24 months, the odds of quitting did not differ between therapy groups (P = 0.07, 0.33, 0.55, respectively).

CONCLUSION: Monotherapy and combination therapy for smoking cessation are similarly effective up to 24 months, and they exhibit similar adverse event attributes.