[Tolerability profile of varenicline in current medical practice]

Varenicline (Champix) was approved in France in 2006 as an aid to smoking cessation treatment. Although there is a consensus on its efficacy, its tolerability is debatable. This article sought to clarify its tolerability profile in current medical practice.

This retrospective study examined tolerance of varenicline prescribed to smokers who wanted to quit smoking in 10 "Stop-Smoking" consultation centers around France. It included all patients who used varenicline during the one-year (February 12, 2007, to February 12, 2008) study period.

At least one adverse event (AE) was reported by 45.9% of the 338 patients, with a total of 343. AE incidence was higher among women (51.5%) than men (40.5%) (OR=1.56, 95% CI: 0.99-2.47, p=0.026). There were 32 unexpected AEs, that is, not listed in the initial new drug application, reported by 23 patients, including 19 psychiatric AEs. Of the 8 serious AEs, 3 were of neurological origin.

This retrospective study confirmed the tolerability issues for varenicline, identified during the phase II-phase III development program and confirmed afterwards. It raises the following questions: Should varenicline be prescribed as a second-line therapy? Is there a patient type for which varenicline would be more - or less - appropriate? Can the tolerability profile be improved by reducing dosage while maintaining the level of efficacy or by co-administering symptomatic treatment more systematically? These are questions that new studies evaluating varenicline tolerability should answer.