A recent study revealed that a highly effective drug used for those who want to quit smoking does not lead to depression or a heart attack, contrary to previous reports.
Varenicline, more popularly known as Chantix in the United States and Champix in Europe, Canada, and other countries, is a prescription drug marketed by Pfizer usually in the form of varenicline tartare, as a treatment for nicotine addiction. The drug works by blocking the pleasant effects of nicotine (from smoking) on the brain. It is a nicotine receptor partial agonist, which means it is used to stimulate nicotine receptors in the body more weakly than nicotine does. It is highly effective in helping patients quit smoking, because, as a partial agonist, it reduces cigarette cravings and decreases tobacco's pleasurable effects.
A known common adverse effect of varenicline is nausea, with less common side effects like headache, sleeping difficulties and abnormal dreams. Changes in taste, vomiting, flatulence, constipation and abdominal pain are also side effects, although they occur rarely.
In November 2007, post-marketing reports of the drug indicated it was said to lead to thoughts of suicide, occasional suicidal behavior, erratic behavior and drowsiness, according to the U.S. FDA. In July 2009, the FDA required a black box warning to be used on varenicline, to note that patients should stop using the drug if the behaviors manifest. A study would later conclude in 2014 that the drug does not lead to suicidal tendencies, but could further worsen psychiatric symptoms in depressed patients.
A recent study published online Sept. 6 in The Lancet Respiratory Medicine found that taking the varenicline treatment or the nicotine antagonist bupropion does not lead to depression, suicidal tendencies or a heart attack.
Researchers from the University of Edinburgh and Dusseldorf analyzed health information obtained from over 150,000 smokers in England, who have been taking varenicline or bupropion, as prescribed for nicotine cessation. They have also used nicotine-replacement therapy like chewing gum, patches or lozenges. The researchers continued to follow the smoking quitters for six months, to determine the impacts of the varenicline or bupropion treatment on their health.
There was no difference found in the risks of a heart attack in both the use of varenicline or bupropion and nicotine-replacement therapy. No high risk of depression or self-harm were identified. According to the researchers, regulators like the U.S. FDA may need to review current safety warnings of the varenicline treatment, which are currently limiting access to an effective nicotine cessation, as they may be unnecessary.
"Smokers typically lose three months of life expectancy to every year of continued smoking. Our research supports the use of varenicline as an effective and safe tool to help people quit," said Daniel Kotz, professor and honorary research fellow at the University of Edinburgh.
The Harvard Medical School, University College London and Maastricht University also contributed to the study, with data provided by QResearch.
