Varenicline linked to serious adverse CV event risk
MedWire News: Varenicline may be linked to an increased risk for serious adverse cardiovascular (CV) events among tobacco users, researchers report.
Varenicline is one of the most widely used drugs for smoking cessation, explain Sonal Singh (John Hopkins University School of Medicine, Baltimore, Maryland, USA) and co-authors in the Canadian Medical Association Journal, but there have been postmarketing reports of adverse CV events associated with its use.
The team conducted a meta-analysis of 14 double-blind randomized controlled trials involving tobacco users (cigarettes or smokeless tobacco) treated with varenicline at doses of up to 1 mg twice daily (n=4908) or placebo equivalent (n=3308).
The study duration of the trials ranged from 7 to 52 weeks. The primary outcome was any ischemic or arrhythmic adverse CV event (myocardial infarction, unstable angina, coronary revascularization, coronary artery disease, arrythmias, transient ischemic attacks, stroke, sudden death, or CV-related death) or congestive heart failure. The secondary outcome was all-cause mortality.
The findings revealed a significantly increased risk of serious adverse CV events associated with varenicline, at 1.06%, compared with placebo, at 0.82% (Peto odds ratio [OR]=1.72, 95% confidence interval [CI]: 1.09-2.71).
There were seven deaths in each group, which the authors say is not enough to draw any meaningful conclusions regarding mortality rates.
Singh et al acknowledge that a risk for neuropsychiatric symptoms such as depression, agitation, and suicidal thoughts associated with varenicline has also been established in the literature.
They note that at the time of publication of their study, the US Food and Drug Administration added a warning to the product label of varenicline about the small increased risk of certain adverse CV events assoiated with its use among smokers with CV disease.
"Clinicians should carefully balance the risk for serious adverse CV events and serious neuropsychiatric adverse events associated with varenicline use against the known benefits of the drug on smoking cessation," they warn.
However, in a related commentary, Taylor Hays argued: "The small absolute risk of CV events associated with taking varenicline is outweighed by the enormous benefit of reducing CV morbidity and mortality that can be achieved with successful abstinence from smoking."
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By Piriya Mahendra