Study finds Pfizer's smoking cessation drug Chantix not linked to heart risks, depression

Study results published in The Lancet Respiratory Medicine suggest that Pfizer's smoking cessation drug Chantix (varenicline) is not associated with an increased risk of cardiovascular events, depression or self-harm when compared with nicotine replacement treatment (NRT). Co-author Aziz Sheikh said it is "highly unlikely that [Chantix] has any significant adverse effects on cardiac or mental health."

The retrospective analysis included 164 766 patients in England who received a prescription of NRT, Chantix or GlaxoSmithKline's Zyban (bupropion) between January 1, 2007, and June 30, 2012. The study included 106 759 patients who received NRT, 51 450 who took Chantix and 6557 given Zyban.

Results showed that neither Chantix nor Zyban were linked with an increased risk of any cardiovascular or neuropsychiatric event compared with NRT. Meanwhile, Chantix was associated with a significantly reduced risk of ischaemic heart disease, cerebral infarction, heart failure, arrhythmia, depression and self-harm.

Sheikh remarked "regulators such as the [FDA] should review its safety warning in relation to [Chantix] as this may be unnecessarily limiting access to this effective smoking cessation aid." Last year, an FDA advisory panel voted in favour of keeping a black boxed warning on the label of Chantix, which had been added in 2009 and updated two years later.

Pfizer is conducting a trial evaluating the neuropsychiatric safety of Chantix versus placebo, NRT and Zyban in patients with and without prior history of psychiatric conditions. Results from the study are expected in late 2015. Chantix generated sales of $647 million last year.

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