Serious neuropsychiatric symptoms and severe skin reactions have been reported in people taking varenicline. Updated advice on managing neuropsychiatric symptoms and a precaution about rare but potentially fatal skin reactions have been added to the product information.¹

Since its launch, drug regulatory agencies in Australia and overseas have raised concerns about possible psychiatric events with varenicline.^2–5

Discuss with patients the potential risks and benefits of varenicline for smoking cessation. Report suspected adverse reactions to the Therapeutic Goods Administration (TGA) online (click ‘Adverse reaction to a medicine’ at left) or by using the 'Blue Card' distributed 3 times a year with Australian Prescriber. For information about reporting adverse reactions, see the TGA website.

For more information about varenicline for smoking cessation read the January 2008 full NPS RADAR review Varenicline (Champix) for smoking cessation.

Monitor all patients for changes in behaviour or thinking, anxiety, psychosis and mood swings

Cases of suicidality (suicidal thinking and suicidal behaviour) in people taking varenicline were identified in a postmarketing safety review by the US Food and Drug Administration (FDA).⁶ The FDA review identified 116 reports of suicidal thinking and 37 reports of suicidal behaviour (half of which [19] resulted in death) in people who started varenicline between May 2006 and November 2007. Of 128 cases that reported time-to-onset of suicidal events, most (86%) occurred during treatment with varenicline. About half the reported suicidal events occurred in people with a history of psychiatric illness.⁶

Advise people taking varenicline and their families of the need to stop varenicline immediately and seek urgent medical advice if they experience symptoms including:

• changes in behaviour or thinking
• anxiety
• psychosis
• mood swings
• suicidal thoughts or behaviours.

Ongoing follow-up of patients with neuropsychiatric symptoms is recommended until symptoms resolve.¹

Postmarketing reports of rare but potentially fatal skin reactions

Rare but severe and potentially fatal cutaneous reactions, including Stevens–Johnson syndrome and erythema multiforme, have been reported in people taking varenicline. The updated Australian product information advises patients to stop taking varenicline and contact their health professional at the first sign of a rash or skin reaction.

For information about reporting adverse reactions, see the TGA website.

References

1. Pfizer Australia Pty Ltd. Champix product information. 29 July 2009.
2. Australian Government Department of Health and Ageing Therapeutic Goods Administration. Aust Adv Drug Reactions Bull 2008;27:22. http://www.tga.gov.au/adr/aadrb/aadr0812.htm
3. Health Canada. Canadian Adverse Reaction Newsletter 2008;18:1–2. http://www.hc-sc.gc.ca/dhp-mps/alt_formats/hpfb-dgpsa/pdf/medeff/carn-bcei_v18n2-eng.pdf
4. Medicines and Healthcare products Regulatory Agency and Commission on Human Medicines. Drug Safety Update 2008;2. http://www.mhra.gov.uk/Publications/Safetyguidance/DrugSafetyUpdate/CON030923
5. US Food and Drug Administration. Public Health Advisory: FDA Requires New Boxed Warnings for the Smoking Cessation Drugs Chantix and Zyban. 2009. http://www.fda.gov/Drugs/DrugSafety/PublicHealthAdvisories/ucm169988.htm (accessed 2 November 2009).
6. US Food and Drug Administration. FDA Drug Safety Newsletter 2009;2. http://www.fda.gov/Drugs/DrugSafety/DrugSafetyNewsletter/ucm107311.htm