When the safety of Pfizer's stop-smoking drug Chantix is debated, usually the focus is on the drug's potential link to psychiatric side effects. But now U.S. regulators have warned that the drug can also boost the risk of cardiovascular problems, including heart attacks.
After reviewing data from a clinical trial, the FDA says it is changing the labeling on Chantix to incorporate new cautionary language for patients with heart disease. The independent study looked at 700 smokers with cardiovascular disease, comparing Chantix with a placebo. The good news was that Chantix was effective at helping patients quit smoking for as long as one year. But the Chantix patients were also more likely to have a heart attack or another cardiovascular complication.
Many of those who try to quit smoking are doing so because of the link to heart attack risks, Reuters points out. Now, there appears to be an association between an effective drug for smoking cessation and adverse cardiovascular events; therefore, the risks and benefits of taking Chantix have to be carefully considered, according to the FDA. "The known benefits of Chantix should be weighed against its potential risks when deciding to use the drug in smokers with cardiovascular disease," the agency said in a statement.
The agency also is requiring Pfizer to study potential heart risks associated with Chantix. The company will be asked to conduct a meta-analysis of randomized, placebo-controlled trials to look for any cardiovascular safety flags.
Chantix hasn't lived up to its initial promise, at least in part because of the safety questions surrounding it. As Reuters notes, the drug's annual sales are now about $750 million, which isn't chump change, but also doesn't amount to the blockbuster-level sales once hoped for.