Varenicline

PFIZER

Oral smoking cessation therapy approved

The activity of varenicline in the aiding of smoking cessation is believed to be the result of the agent's action at a sub-type of the nicotinic receptor where it acts as an agonist while simultaneously preventing nicotine binding to alpha₄beta₂ receptors. Varenicline was approved on May 10, 2006, as an aid to smoking cessation treatment.

Safety. Patients should be informed that some medications may require dose adjustment after quitting smoking. Nausea was the most common adverse event reported in association with varenicline treatment. This dose-dependent nausea was generally described as mild or moderate and often transient in nature; however, some patients have reported nausea that is persistent over several months. Other adverse events reported in association with varenicline treatment include sleep disturbance, constipation, flatulence, and vomiting.

Dosing. Varenicline should be taken after eating and with a full glass of water. Varenicline should be dosed at 1 mg BID following a 1-week titration. This titration should begin with 0.5 mg QD on Days 1 to 3, followed by 0.5 BID on Days 4 to 7. Patients should receive varenicline therapy for 12 weeks, followed by an additional 12 weeks of therapy for those who have successfully quit smoking to increase the likelihood of further abstinence. For patients with severe renal impairment, a maximum daily dose of 0.5 mg BID is recommended. Patients with end-stage renal disease undergoing hemodialysis should received a maximum dose of 0.5 mg QD if the drug is tolerated well.