The Food & Drug Administration recently approved varenicline (Chantix, Pfizer) as an aid to smoking cessation. Varenicline is the first new prescription treatment for smoking cessation to receive FDA approval in nearly a decade and only the second nicotine-free smoking cessation therapy ever approved by the agency. This new molecular entity received priority review because of its potential benefit to public health. Pfizer plans to make the drug available in U.S. retail pharmacies in the second half of 2006-most likely during the third quarter.
In addition, varenicline's high affinity for the α4β2 receptor blocks nicotine from binding. Nides said such long-lasting binding blocks the effects of nicotine if people smoke while taking varenicline, noting that this reduces the possibility of a slip becoming a full-blown relapse.
Patients should be instructed to set a "quit date" and to begin treatment with varenicline one week before that date, according to Nides. The recommended starting dose is one 0.5-mg tablet once per day for the first three days, one 0.5-mg tablet taken twice per day (morning and evening) for the next four days, and one 1-mg tablet twice per day from day 8 until the end of treatment.
No dosage adjustment is required in those with mild-to-moderate renal impairment. For those with severe renal impairment, the recommended starting dose is one 0.5-mg tablet once per day. Patients can then titrate as necessary to a maximum dose of one 0.5-mg tablet twice per day. For patients with end-stage renal disease undergoing hemodialysis, a maximum dose of one 0.5-mg tablet taken once per day can be administered if it is well-tolerated.
The duration of treatment with varenicline is 12 weeks. If treatment is successful, the manufacturer recommends an additional 12 weeks of varenicline therapy to prevent relapse.
Smoking cessation therapies are most effective when combined with counseling and a behavioral modification program, Nides said. All varenicline patients will be able to enroll in a behavioral support program free of charge. Patients and healthcare providers can call (877) CHANTIX (242-6849) or access http:// http://www.chantix.com/ for more information.