Background: Nicotine replacement therapy (NRT) and varenicline are both effective in helping smokers quit. There is growing interest in combining the two treatments to improve treatment outcomes, but no experimental data exist on whether this is efficacious. This double-blind randomised controlled trial was designed to evaluate whether adding nicotine patches to varenicline improves withdrawal relief and short-term abstinence rates.
Methods: 117 participants seeking help to stop smoking were randomly allocated to varenicline plus placebo patch or varenicline plus nicotine patch (15 mg/16 hour). Varenicline use commenced one week prior to the target quit date (TQD), patch use started on the TQD. Ratings of urges to smoke and cigarette withdrawal symptoms were collected weekly over 4 weeks post-TQD. Medication use and smoking status were established at 1, 4 and 12 weeks. Participants lost to follow-up were included as continuing smokers.
Results: 92% of participants used both medications during the first week after the TQD. The combination treatment generated no increase in nausea or other adverse effects. It had no overall effect on urges to smoke or on other withdrawal symptoms. The combination treatment did not improve biochemically validated abstinence rates at 1 week and 4 weeks post-TQD (69% vs 59%, p=0.28 and 60% vs 59%, p=0.91, in the nicotine patch and placebo patch arm, respectively), or self reported abstinence rates at 12 weeks (36% vs. 29%, p=0.39, NS).
Conclusions: The efficacy of varenicline was not enhanced by the addition of nicotine patches, although further trials would be useful to exclude the possibility of type II error.
Trial registration: Clinicaltrials.gov
Registration number: NCT01184664.