A new study that compares American global pharmaceutical corporation Pfizer's Chantix smoking cessation drug has revealed that it does not increase patients' risk of neuropsychiatric side effects, a step forward in the company's mission to get the FDA to remove the black box warning off of the product.
The study consisted of a randomized controlled trial called EAGLES and included 8,144 smokers in 16 countries. Over the course of 12 weeks, the patients used either a placebo, a nicotine patch, Chantix or Zyban, another smoking cessation drug from the pharmaceutical company GlaxoSmithKline. After the study period, there was 12 weeks of follow-up.
In each patient group, subjects were divided into two additional groups: those with preexisting psychiatric disorders and those without. The results revealed that just 1.3 percent of people without psychiatric disorders using Chantix experienced moderate to severe side effects, compared to 2.2 percent of Zyban patients, 2.5 percent of nicotine patch users and 2.4 percent of the placebo group.
For the group with psychiatric disorder, 6.5 percent of people taking Chantix experienced moderate to severe side effects, 7.6 percent for those using Zyban, 2.5 percent for those using the nicotine patch and 2.4 percent for the placebo group.
While Chantix users showed the lowest rate of side effects across all groups, the study also revealed that it was also the most effective for smoking cessation, with more patients using the medication successfully abstaining than those who used Zyban, the patch or a placebo. Interestingly, Zyban used in conjunction with a patch helped more patients abstain than a placebo did.
"This is the largest randomized, controlled trial to date comparing these smoking-cessation medications directly and comparing them with placebo," said Robert Anthenelli, professor of psychiatry at the University of California San Diego School of Medicine and lead author of the study. "We are hoping that the recognition that these medications are safe for smokers with and without psychiatric disorders will encourage people to try and quit, and feel comfortable that they can use any of the available medications."
"We believe the available scientific information doesn't support a boxed warning," said Freda Lewis-Hall, Pfizer's chief marketing officer, adding that the study continues to support "the large body of clinical evidence characterizing the neuropsychiatric safety and efficacy of (Chantix)."
The findings were published in the April 22 issue of The Lancet.
