Varenicline (Champix®) and suicidal ideation, aggression and drowsiness
admin November 22nd, 2007
The FDA have drawn attention to reports of suicidal thoughts and aggressive and erratic behavior in patients who have taken varenicline. Varenicline is known by the tradename Chantix in the US market and Champix in the UK. On suicidal thoughts the FDA say:
The manufacturer of Chantix, Pfizer, Inc., recently submitted to FDA postmarketing cases describing suicidal ideation and occasional suicidal behavior. FDA currently is reviewing these cases, along with a number of recent reports in the popular press and internet sites. A preliminary assessment reveals that many of the cases reflect new-onset of depressed mood, suicidal ideation, and changes in emotion and behavior within days to weeks of initiating Chantix treatment. The role of Chantix in these cases is not clear because smoking cessation, with or without treatment, is associated with nicotine withdrawal symptoms and has also been associated with the exacerbation of underlying psychiatric illness. However, not all patients described in these cases had pre-existing psychiatric illness and not all had discontinued smoking.
The case of aggressive and erratic behaviour may have also been associated with comfounding factors, such as alcohol use, and the FDA are continuing to examine additional material supplied by the manufacturer.
The FDA is also evaluating cases of drowsiness that affected the ability to drive, and have recommended that “Patients should use caution when driving or operating machinery until they know how quitting smoking with Chantix may affect them.”
Bottom line:: Although the role of varenicline in these cases of suicidal thoughts and aggression is not conclusively proven, healthcare professionals should be aware of these reported cases. Varenicline is a black triangle medicine in the UK, meaning that any suspected reactions (no matter how trivial) should be reported to the Yellow Card scheme. Drowsiness is a listed adverse reaction of varenicline in the UK; healthcare professionals should warn patients who drive or operate other heavy machinery to be aware of this potential adverse effect.