Marketed in the U.S. as Chantix and other nations as Champix, another bomb just fell on Pfizer's quit smoking pill varenicline. According to a just released report by The Institute for Safe Medication Practices (ISMP), a non-profit medication watchdog, "In the first quarter of 2008, varenicline accounted for more reports of serious injury than the 10 best selling brand name prescription drugs combined."

The report indicates that the U.S. Food and Drug Administration (FDA) received serious adverse event reports on 773 different drugs during the 1st quarter of 2008. Chantix again topped the list. During the 1st quarter there were 1,001 new reports of serious injuries among varenicline users, including 50 additional deaths. By comparison, varenicline users accounted for 998 serious injury reports and 78 deaths during the 4th quarter of 2007.

The ISMP report notes that there were only 17 reports of serious injury among all forms of nicotine replacement therapy combined (the nicotine patch, gum, lozenge, spray, and inhaler). This important quitting method risk data, when combined with results from the only head-to-head study pitting varenicline against NRT, should allow FDA officials to engaged in informed risk-benefit analysis.

A Pfizer smoking cessation study published in February 2008 compared 10 weeks of nicotine patch use to 12 weeks of varenicline use. Even after Pfizer gifted varenicline a two-week treatment advantage, varenicline failed to prove superior in 7-day point prevalence findings. Participants were asked at both 6 months and 1 year whether or not they had smoked a cigarette in the past 7 days. Pfizer's researchers, which included four Pfizer employees, were forced to report that there "were no significant differences" between nicotine patch and Chantix smoking abstinence rates at either 6 months or a year.

According to the ISMP report, varenicline again recorded the highest number of suicide/self-harm events of any medication with 226. The combined total for the next two closest drugs reporting suicide attempts was 22% less (oxycodone with 89 reports and acetaminophen with 87).

The ISMP report contends that broader warnings are needed. It encourages the FDA and Pfizer to add a prominent warning about accident risks to both the patient Medication Guide and prescribing information sheet for doctors, a warning similar to the new warnings about psychiatric side effects.

The report also flags additional kinds of side effects, including serious accidental injuries. It highlights traffic accidents and concerns that varenicline induced seizures, disturbances in vision, panic attacks or impaired judgment may be playing a role.

It encourages further investigation of possible varenicline links to diabetes, potentially life-threatening interruption of the heart rhythm, heart attacks, strokes, and moderate to severe allergic reactions.

The ISMP's earlier May 2008 report raised concerns about potential alertness and motor control related accidents among transportation industry workers using varenicline. In response, the Federal Aviation Administration banned the use of Chantix by airline pilots, the Department of Transportation limited its use among truck drivers, and the Department of Defense prohibited its use by aircraft and missile crews.

This time the bomb dropped on varenicline may prove fatal. If varenicline is not more effective than NRT, while causing nearly 5,800% reports of greater harm than NRT, then why is it still on the market? If the FDA has difficulty answering this question, it may well be that our nation's medication system has far greater concerns than just varenicline.

---

---