The Therapeutic Goods Administration (TGA) has updated the product information for varenicline as a result of ongoing safety surveillance. Varenicline is a partial nicotinic receptor agonist used to reduce nicotine cravings and withdrawal symptoms in conjunction with a comprehensive smoking cessation program. Listed on the Pharmaceutical Benefits Scheme (PBS) in January of 2008, over 1.1 million prescriptions have since been dispensed in Australia. During that period, varenicline has been associated with 316 cases of suicidal thoughts and suicide attempts that have resulted in 34 deaths. A number of other serious neuropsychiatric reactions, including depression, aggression, and homicidal ideation, have also been reported.
Smoking cessation has long been associated with transient negative effects on mental health, whether pharmacotherapy is utilised or not. Although a study recently published in the British Medical Journal failed to find a causal relationship between varenicline and neuropsychiatric effects, it is recommended that patients cease treatment immediately if they experience any changes to their behaviour, thinking or mood. Consumption of alcohol should be avoided during treatment as it may increase the risk of adverse effects and result in increased levels of intoxication.
Clinical trials demonstrate the odds of successfully quitting smoking with varenicline to be 3.91 times greater than placebo and 1.96 times greater than bupropion. Smoking continues to be the largest single preventable cause of death in Australia, therefore appropriate utilisation of smoking cessation programs are an essential public health measure.
- Champix® (varenicline tartrate) Australian approved product information. West Ryde: Pfizer Australia Pty Ltd. Amended 27 October 2015.
- Therapeutic Goods Administration. Safety advisory – risks of psychiatric symptoms and potential interaction with alcohol. Canberra: Therapeutic Goods Administration; 2015.
- Thomas KH, Martin RM, Knipe DW, Higgins JT, Gunnell D. Risk of neuropsychiatric adverse events associated with varenicline: systematic review and meta-analysis. BMJ. 2015; 350: h1109.