Pharmacokinetics, safety, and tolerability after single and multiple oral doses of varenicline in elderly smokers

Varenicline is a novel selective alpha 4 beta 2 nicotinic acetylcholine partial agonist developed for smoking cessation. This study investigated the single- and multiple-dose pharmacokinetics, safety, and tolerability of varenicline in elderly (>= 65 years) smokers. Twenty-four elderly smokers with normal renal function for their age (estimated creatinine clearance >= 70 mL/min) received varenicline 1 mg once daily (n = 8) or placebo (n = 4) for 7 days, or 1 mg twice daily (n = 8) or placebo (n = 4) for 6 days with a single dose on day 7 in a double-blind, parallel group and placebo-controlled design. There was no evidence of concentration- or time-dependent changes in varenicline pharmacokinetics upon repeat dosing. Once- and twice-daily dosing was associated with an approximate 2-fold and 3-fold increase, respectively, in systemic exposure to varenicline. Varenicline was well tolerated; all adverse events reported were mild to moderate in intensity. Thus, no dose adjustment is necessary based on age alone.