Varenicline ( Champix ) is an aid to smoking cessation; it was launched in the United Kingdom ( UK ) in December, 2006.
Varenicline is a partial agonist at the nicotinic alpha4beta2 receptor.
15 000-20 000 patients have used Varenicline since its launch.
Up to 26 September, 2007 the MHRA had received 839 reports of suspected adverse drug reactions in relation to the use of Varenicline.
Most of these reports were of well-recognised adverse drug reactions for this medicine, such as: nausea 183, headache 82, vomiting 67, abnormal dreams 52, dizziness 49, fatigue 37, insomnia 34, somnolence 21.
Possible effects on driving
Healthcare professionals and patients should be aware of the possible effects of Varenicline on driving.
The Summary of Product Characteristics ( SPC ) advises that patients should not drive until they know whether Varenicline affects their driving ability; a similar warning is in the Patient Information Leaflet.
The MHRA has received 46 reports of depression associated with the use of Varenicline, generally in patients with a previous psychiatric history, and 6 reports of suicidal ideation.
The MHRA is monitoring closely the issue of suicidality in patients taking Varenicline.
Of note: stopping smoking, with or without medication, may exacerbate an underlying psychiatric condition.
The SPC for varenicline advises particular care in patients with a previous history of psychiatric illness, and states that patients should be advised accordingly.
Effects on drug metabolism
Healthcare professionals should be aware that stopping smoking, with or without medication, may affect the metabolism of some drugs, for which dose adjustment may be essential ( eg, Insulin, Theophylline, and Warfarin ).
Source: MHRA Drug Safety Update, 2007