Varenicline: adverse psychiatric reactions, including depression

Varenicline (Champix▼) is a non-nicotine aid to smoking cessation and was launched in the UK in December, 2006. It is a partial agonist at the nicotinic α4β2 receptor, and can help to relieve the cravings and nicotine withdrawal symptoms associated with stopping smoking. Up to the end of June 2008, approximately 450 000 people had used varenicline in the UK.

In the July 2008 issue of Drug Safety Update, we gave important advice for healthcare professionals, patients, and carers relating to the risk of suicidal thoughts and behaviour. Since that time, we have received further reports of suspected adverse events associated with varenicline. As the time of year approaches when many people consider giving-up smoking, we would like to remind you of this advice (outlined below), and to ask you to help ensure that patients, their family, or their caregivers are advised accordingly.

Up to 29 Sept, 2008, 3541 reports of suspected adverse reactions have been received for varenicline via the Yellow Card scheme in the UK.

Alongside psychiatric reactions, sleep disorders (including insomnia and abnormal dreams) and gastrointestinal reactions (particularly nausea and vomiting) have been the most commonly reported side-effects.

It is important to note that the suspected reactions are not necessarily caused by the drug and may relate to other factors such as nicotine withdrawal, other illnesses, or other medications taken concurrently by the patient.

Depression and suicide-related events

Stopping smoking—with or without medication—may be associated with various psychiatric symptoms such as depressed mood (rarely including suicidal ideation), irritability, anxiety and frustration, or anger; stopping smoking may also exacerbate an underlying psychiatric condition. However, suicide-related events have been reported in patients taking varenicline who have no known pre-existing psychiatric conditions and in patients who continued to smoke.

The most frequently reported psychiatric disorders are depression or depressed mood, and suicidal ideation.

NICE guidance

The National Institute for Health and Clinical Excellence (NICE) recommends the use of varenicline as an option for smokers who have expressed a desire to quit, and that it should normally be prescribed only as part of a programme of behavioural support.

When deciding which smoking cessation therapies to use and in which order, prescribers should take into account the contraindications and the potential for adverse effects.

We continue to closely monitor the issue of psychiatric reactions in patients taking varenicline, and wider European review is ongoing. Please continue to report to us via the Yellow Card Scheme all reactions which you suspect may be related to the use of varenicline—including any considered not to be serious and reactions that are well-recognised. You do not have to be certain about causality; if in doubt, please report at www.yellowcard.gov.uk.

Further information

Information about varenicline from the National Prescribing Centre

Download a summary of reported suspected adverse reactions for varenicline

Article citation: Drug Safety Update Nov 2008, vol 2 issue 4: 2.