Varenicline tartrate (Chantix, Champix) is effective in helping smokers stop smoking. Unfortunately, ome patients may have significant adverse psychiatric effects while taking the drug.


Mechanism: alpha-4, beta-2 selective nicotinic acetylcholine receptor (nAchR) partial agonist


Patients with pre-existing psychiatric disorder are at increased risk, but these reactions may occur in patients without any prior history of comorbid psychiatric disorders.


Adverse effects include:

(1) worsening of depression or anxiety

(2) suicidal thoughts or actions

(3) violence towards others and/or hostility

(4) hallucinations

(5) bizarre and vivid dreams

(6) changes in behavior, including mania

(7) agitation or restlessness

(8) mental confusion

(9) impulsivity

(10) paranoia

(11) insomnia

(12) fatigue


Differential diagnosis:

(1) effects of nicotine withdrawal

(2) pre-existing mental disorder


Varenicline is implicated if the symptoms appear or worsen while on varencline but disappear or improve when it is stopped.


Karam-Hage et al reported a patient whose symptoms improved by the addition of buproprion SR while taking varenicline.


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