Chantix Warnings Cause Sharp Drop in Sales

According to their second quarter earnings statement, Pfizer reported a substantial drop in U.S. sales of their once promising anti-smoking drug, Chantix. Warnings about an association with psychological side effects like suicide, depression and abnormal behavior have caused some doctors and patients to seek alternative therapies to help them quit smoking.

Last Wednesday, Pfizer indicated that their quarterly earnings more than doubled compared with the same period last year. However, they saw a 35% drop in sales for Chantix, mainly due to concerns about an increased risk of suicides which surfaced late last year, and a study released in May 2008 which outlined a number of other potential side effects which could be associated with the drug.

Chantix (varenicline tartrate) was introduced in the United States by Pfizer in 2006 as a prescription drug to help people quit smoking. It works by affecting nicotine receptors in the brain, which reduces nicotine cravings and helps promote long-term smoking cessation.

After the drug was approved by the FDA in May 2006, sales quickly took off, generating $883 million during the first full year on the market. It quickly became one of their most important products for Pfizer, and the pharmaceutical company was relying on the drug to become their next blockbuster since analysts generally agree that they have a weak pipeline of new products and will be losing patent protection on several of their best selling medications.

Pfizer updated the Chantix warning label in November 2006 to indicate an association between the use of Chantix and suicides. The suicide warning was strengthened in January 2008, and the FDA has been investigating hundreds of reports of Chantix side effects which allegedly caused suicidal thoughts, psychosis, hostility, aggression and death.

In May 2008, the Institute for Safe Medication Practices, a nonprofit watch dog group, raised further concerns about the safety of Chantix after they published a review of all adverse event reports received by the FDA between May 2006 and December 2007. In addition to the psychological side effects previously linked to Chantix, the report identified a possible association between Chantix and new on-set of diabetes, an increased risk of injury caused by seizures, black outs, vision disturbances and other sudden medical problems, as well as a potential increased risk of a severe skin reaction to the drug, known as Stevens Johnson Syndrome.

Due to reports of associated health concerns, the drug came under scrutiny and its popularity among Americans has suffered. As of July 23, 2008, the U.S. sales of the drug were $109 million, down more than a third when compared with the same period a year-earlier. However, foreign sales during the quarter were up 197%, at $98 million. The drug was launched as Champix in Japan, Malaysia and Singapore last quarter, and is slated for launch in China, Russia and Turkey in the next 12 months despite the safety concerns which have surfaced in the United States.

At least two Chantix lawsuits have already been filed by users who died or suffered severe physical injuries as a result of psychological side effects allegedly caused by the medication. Pfizer did not address the recently filed Chantix litigation in their earnings statement, but product liability lawyers expect that potentially hundreds of other cases may be filed in the coming months.