A double-blind study evaluating the long-term safety of varenicline for smoking cessation.
OBJECTIVE
We assessed the safety of long-term varenicline administration for smoking cessation.


METHODS
In this randomized, double-blind, multicenter trial, eligible adult smokers (18-75 years) who smoked an average of > or =10 cigarettes/day were randomized to either varenicline 1 mg twice daily (BID) or placebo for 52 weeks. Subjects made weekly clinic visits until week 8, and then every 4 weeks until week 52, with a follow-up visit at week 53. The target quit date was the morning of the week 1 clinic visit. Brief counseling was provided at each visit, and vital signs, adverse events (AEs), and smoking status were documented. Other laboratory measures were collected at specified visits.


RESULTS
A total of 251 subjects were randomized to varenicline and 126 to placebo. Approximately half of the subjects in each arm completed the study (53.8% varenicline; 46.8% placebo). Treatment-emergent AEs were observed in 96.4% of varenicline- and 82.5% of placebo-treated subjects during the study. Common varenicline-associated AEs were nausea (40.2%), abnormal dreams (22.7%), and insomnia (19.1%). Most AEs were considered mild or moderate in intensity. AEs leading to discontinuation of varenicline treatment included nausea (7.6%), insomnia (3.2%), and abnormal dreams (2.4%). A single varenicline-related serious AE, bilateral subcapsular cataracts, was observed. At week 52, 7-day point prevalence abstinence rates were 36.7% (varenicline) and 7.9% (placebo).


CONCLUSIONS
Varenicline 1 mg BID can be safely administered for up to 1 year. Varenicline was also a more effective smoking cessation aid than placebo throughout the study, supporting both its short- (12-week) and long-term (52-week) efficacy.
Williams
Kathryn E
KE
Pfizer Global Research & Development, Groton, CT 06340, USA. kathryn.e.williams@pfizer.com
Reeves
Karen R
KR
Billing
Clare B
CB
Pennington
Ann M
AM
Gong
Jason
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D001552:Benzazepines / Q000009:adverse effects / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010919:Placebos; D011810:Quinoxalines / Q000009:adverse effects / Q000627:therapeutic use*; D016540:Smoking Cessation / Q000379:methods*; D000074606:Smoking Prevention; D013995:Time; D013997:Time Factors; D016896:Treatment Outcome; D000068580:Varenicline
D001552:Benzazepines; D010919:Placebos; D011810:Quinoxalines; D000068580:Varenicline