Use of Chantix (Varenicline) for 4 Weeks Before Quitting Smoking
"The smoking-cessation drug Chantix (varenicline) may work better if people take it several weeks before trying to quit," according to a study published Monday in the Archives of Internal Medicine. Investigators gave Chantix to "53 people beginning four weeks before their quit date and throughout the remainder of the three-month cessation period. That group was compared with people who were given three weeks of a placebo pill followed by one week of Chantix before their quit day and for the remainder of the study." Investigators found that those who started Chantix "for a month before the quit date were more likely to be abstinent at the three-month mark: 47.2% were abstinent compared with 20.8% of the people in the placebo group."
The ?4?2 nicotinic receptor partial agonist varenicline tartrate is an effective smoking cessation medication. It is used in dosages increasing from 0.5 to 1 mg/d for 1 week before the target quit date (TQD) to generate sufficient systemic levels and to habituate users to the possible occurrence of nausea and thereafter in dosages of 2 mg/d for up to 6 months.
Varenicline seems to affect smokers in 2 different ways. It alleviates withdrawal discomfort and urges to smoke after smokers stop smoking. This effect is ascribed to the action of varenicline on dopaminergic pathways. Treatment is intended to ensure that ex-smokers continue to receive at least a part of the boost to their dopamine levels in the nucleus accumbens that they previously obtained from smoking. The second effect consistsof a reduction in the enjoyment of smoking and in smoke intake. This is presumed to be caused by the drug's blocking of the receptors that would otherwise facilitate the "reward" experienced when smoking. Up to now, this second effect has only been demonstrated over 1-week uptitration before the TQD and in unsuccessful quitters who rated the enjoyment of their "lapse" cigarettes.
The therapeutic effects of varenicline when administered as per current labeling rely primarily on the first mechanism (ie, alleviation of withdrawal discomfort once smokers stop smoking). Researchers hypothesized that, if the drug lowers the subjective reward that accompanies smoking, its use over an extended period before the TQD (varenicline preloading) could help to weaken the association of smoking with reward and to enhance cessation and the efficacy of varenicline therapy.
The present trial was designed to test whether varenicline preloading for 4 weeks reduces urges to smoke and facilitates smoking cessation compared with using the drug for just 1 week before the TQD as per current labeling. They also tested whether any smoking cessation effect is mediated by the influence of varenicline preloading on ad lib smoke intake before quitting or its effect on postcessation withdrawal discomfort. Last, they attempted to determine whether any effects of varenicline preloading plateau within 4 weeks of exposure.
Hajek P, McRobbie HJ, Myers KE, Stapleton J, Dhanji A-R.
Use of Varenicline for 4 Weeks Before Quitting Smoking: Decrease in Ad Lib Smoking and Increase in Smoking Cessation Rates. Arch Intern Med 2011;171(8):770-7.
Arch Intern Med -- Abstract: Use of Varenicline for 4 Weeks Before Quitting Smoking: Decrease in Ad Lib Smoking and Increase in Smoking Cessation Rates, April 25, 2011, Hajek et al. 171 (8): 770
Background The use of varenicline tartrate alleviates postquit withdrawal discomfort, but it also seems to reduce the "reward" associated with smoking. The current treatment schedule, which commences 1 week before quitting, relies primarily on the first mechanism. We set out to determine whether increasing the prequit medication period renders cigarettes less satisfying and facilitates quitting.
Methods One hundred one smokers attending a stop-smoking clinic in London, United Kingdom, were randomly allocated to receive varenicline for 4 weeks before the target quit date (TQD) or to receive placebo for 3 weeks before the TQD, followed by varenicline for 1 week before the TQD. In both groups, standard varenicline treatment was given for 3 months after the TQD. Measures included smoking satisfaction and smoke intake before quitting, urges to smoke and withdrawal discomfort after quitting, and sustained abstinence from the TQD to 3 months.
Results Varenicline preloading reduced prequit enjoyment of smoking (P = .004) and smoke intake (P < .001), with 36.7% of participants reducing their cotinine concentrations by more than 50% (reducers). Varenicline preloading did not affect postquit withdrawal symptoms, but it increased 12-week abstinence rates (47.2% in the varenicline arm vs 20.8% in the placebo arm, P = .005). The effect was particularly strong among the reducers in the varenicline arm (66.7% in reducers vs 22.6% in nonreducers, P = .002). Varenicline preloading was well tolerated.
Conclusions Although several issues remain to be clarified, varenicline preloading can generate a substantial reduction in ad lib smoking and enhance 12-week quit rates. Current treatment schedules may lead to suboptimal treatment results. Trials with longer follow-up periods are needed to corroborate these findings.