Depression, serious heart events linked to Chantix: Chantix, the anti-smoking pill once heralded as a blockbuster drug and a major breakthrough in the science of helping smokers butt out, has been racking up a bad reputation for being linked to psychiatric problems and heart problems.
In a recent study, U.S. researchers said the popular smoking-cessation medication, made by drug maker Pfizer and sold as Champix in Canada, Europe and other countries, was linked to suicidal thoughts and aggression.
The new study, published in the journal PLoS One in November 2011, reviewed 3,249 case reports of smokers who experienced depressive symptoms while using medications to help them butt out.
“We found that Chantix is associated with more suicidal reports than any other smoking-cessation drug on the U.S. market,” said study co-author Curt Furberg of Wake Forest Baptist Medical Center in Winston-Salem N.C. “The risks simply outweigh the benefits.”
Another study published by the Canadian Medical Association Journal [via The Globe and Mail] last June found that people who took Chantix to help them stop smoking may have an increased risk for cardiovascular problems.
The new studies only highlight growing doubts over the safety of the drug, also known by its generic name varenicline tartrate.
The drug has been the subject of probes by both the United States Food and Drug Administration and Health Canada, for being linked to both psychiatric and heart problems.
Since Chantix was first released in markets in 2007, Health Canada has issued several public advisories warning consumers about the side effects of the anti-smoking drug. From 2007 to 2011, the U.S. FDA has issued 13 safety warnings on Chantix.
Boxed psychiatric warnings
On June 4, 2010 Canada’s public health officials , as well as Pfizer, issued a strong warning about the
anti-smoking pill, prompted by mounting public reports that the drug caused mood changes, depression, suicidal thoughts hostility, suicidal behavior and serious, sometimes fatal, skin reactions.
Health Canada received more than 1,200 reports of adverse reactions associated with Champix since it came on the market in Canada in April 2007, the Globe and Mail reported.
And since 2008, Health Canada has issued several warnings, telling patients and health-care professionals that varenicline may be linked to depression, agitation, aggression, hostility and thoughts of self-harm. Alcohol intake could increase the risk to patients, Health Canada warned.
The U.S. FDA also issued a similar warning in July 2010.
In both North American countries, the drug must now carry a boxed warning, the highest warning both public health agencies reserve for drugs that have been linked to serious safety issues or adverse events.
Both health authorities say numerous patients taking Chanpix experienced serious neuropsychiatric symptoms—depressed mood, agitation, aggression, hostility and thoughts of self-harm or suicide—even when they had no history of psychiatric disorders.
In the warnings, Health Canada and the U.S. FDA also highlighted reports of dizziness, loss of consciousness, seizures and other serious side effects linked to the drug.
Some patients using Chanpix have also experienced serious skin reactions, including angioedema, characterized by swelling under the skin that can be fatal, and other severe skin reactions, the warnings said.
The warnings also included more comprehensive information for health professionals and patients about taking the drug and monitoring for potential problems. It also includes an option for patients to take a lower dosage of the medication instead of moving to a higher dose, as was traditionally recommended.
But public health officials have also cautioned that it was always difficult to tease out whether a drug was the direct cause of a side effect among all the factors at play.
And the depressions suffered by the ex-smokers taking Chantix may only be part of withdrawal symptoms, some doctors say.