The popular anti-smoking drug varenicline, which is sold under the brand names Chantix and Champix, is more strongly linked to suicide, suicide attempts, and depression than some other common smoking-cessation aids, according to a study out today in the online medical journal PLoS One.
Researchers looked at adverse drug events reported by doctors, patients, and other people to the Food and Drug Administration’s MedWatch database between 1998 and September 2010. It found 2,925 submissions suggesting a connection between varenicline and depression, suicide attempt, and suicide. That compared with 229 reports for bupropion, an antidepressant also used to help people stop smoking that’s sold under the brand name Zyban and as a generic; and 95 reports for nicotine-replacement products, which include patches, gum, or lozenges that you can buy over the counter, and prescription nasal sprays or inhalers.
It’s difficult to calculate precisely how common the problems are from reports to the MedWatch database, says Thomas Moore, lead author of the report and a senior scientist at the Institute for Safe Medication Practices as well as a paid consultant to Consumer Reports Best Buy Drugs. But estimates suggest less than 10 percent of adverse drug events are reported to the FDA, so the actual number of problems is likely much higher than the amount found in the study.
An announcement last week about two other FDA-supported studies—one from the Department of Veterans Affairs and another from the Department of Defense—appeared to offer reassuring news about varenicline. Neither found a link between the drug and psychosis severe enough to require hospitalization. But the FDA said both studies were too small to detect rare events. So the drug will still carry a black box warning—the strongest warning the FDA can issue—about those risks, which include changes in behavior, hostility, agitation, depressed mood, and suicidal thoughts or actions. And a Medication Guide that details the possible side effects must accompany every varenicline prescription. The FDA has also ordered Pfizer, the manufacturer of Chantix, to conduct a trial focusing on the safety of the drug, though results won’t be available until 2017.
Besides those risks, last summer the FDA reported that a 700-person trial found that varenicline might also increase the risk of heart attack and other cardiovascular events in people who have cardiovascular disease.
Bottom line: Although varenicline, as well as bupropion, can help some people quit smoking, our medical consultants continue to suggest trying safer alternatives first. For most people, that means counseling, nicotine-replacement products, or both. Those products are most helpful for the first two to three months of quitting, when the risk of relapse is greatest. Taking them for longer than that should only be done under the supervision of your doctor since there is a risk of becoming addicted to the replacements themselves.
Varenicline and bupropion should generally be considered only if you’ve tried and failed with other measures. If you do take either drug, stop immediately and contact your doctor if you become agitated, hostile, or depressed, or if you experience changes in behavior or thinking, especially regarding suicide.
For details on other available options, see our advice on how to quit smoking.
Suicidal Behavior and Depression in Smoking Cessation Treatments [PLoS One]
FDA Drug Safety Communication: Chantix Safety Review: Risks of Psychosis [FDA]
FDA Drug Safety Communication: Chantix May Increase the Rate of Certain Cardiovascular Events [FDA]
These materials are made possible by a grant from the state Attorney General Consumer and Prescriber Education Grant Program, which is funded by the multi-state settlement of consumer-fraud claims regarding the marketing of the prescription drug Neurontin (gabapentin).