Chantix may be safe with treated depression: study

In a trial among people with a history of depression, those taking the quit-smoking aid varenicline - marketed in the U.S. as Chantix - were no more prone to depression or thoughts of suicide than those on a placebo, according to a new study.

In 2007, the U.S. Food and Drug Administration (FDA) announced reports of serious side effects including suicidal thoughts and erratic behavior in some people taking Chantix to stop smoking. The agency and Chantix manufacturer Pfizer said at the time it was unclear whether the symptoms were caused by the drug or by nicotine withdrawal.

Two years later, the FDA added a "black box warning" about these possible side effects to packages of Chantix and to another drug prescribed for smoking cessation, Zyban.

But the new trial results showing no greater depression risk while quitting smoking with Chantix, even in depression-prone patients, are not surprising according to lead study author Dr. Robert Anthenelli of the Veterans Affairs San Diego Healthcare System in California.

"Our prior experience using the medication in smokers with and without mental health disorders, and the results of more than 15 placebo-controlled randomized clinical trials found no such association," he told Reuters Health.

About half of smokers seeking help in quitting are depressed or have suffered from depression and related disorders in the past, Anthenelli's team points out in the Annals of Internal Medicine. Yet previous trials of drugs to aid smoking cessation have generally excluded people taking antidepressants or antipsychotic drugs to treat mental disorders, they write.

To test whether varenicline would help such patients quit smoking without exacerbating depression, Anthenelli and his fellow researchers, many of whom work for Pfizer, randomly assigned 525 adult smokers to take varenicline or a placebo.

All the trial participants had stable treated current or past major depression and no recent cardiovascular problems. They ranged in age from 18 to 79 and two thirds were women.

About three quarters of participants regularly used antidepressants and antianxiety drugs during the study, but people using other smoking-cessation medications, non-cigarette tobacco products or marijuana were excluded, as were people taking antipsychotic medications.

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.