Quit smoking medicine: new study notes more side effects

National Prescribing Service Limited (NPS) advises people with questions about the quit-smoking drug varenicline (marketed in Australia as Champix) to contact their doctor or pharmacist for advice.

The reminder from NPS comes following the release of a report in the United States recently that is generating questions and concern about potential adverse events with varenicline. Varenicline (Champix) is a new non-nicotine drug to help people to quit smoking that has been available on the Pharmaceutical Benefits Scheme (PBS) since 1 January 2008.

People who use or intend to use varenicline should be aware that like all medicines, it can have side effects. Sometimes the side effects of medicines are serious but most of the time they are not. Some of the adverse events noted in this new report are similar to those reported during clinical trials but others appear to be new.

“As with any drug, people need to be aware of the possibility of side effects and to discuss any concerns they have with their doctor or pharmacist. Varenicline is a new drug, so as more people use it is realistic to expect more reports of side effects and for side effects which are not yet known to come to light”, said Ms Karen Kaye, Acting CEO, NPS.

Nausea, or a feeling of wanting to be sick, affects about one in three people who take varenicline. Other common adverse effects include insomnia, abnormal dreams, headache and constipation.

During the time that it has been available overseas, some individuals using varenicline have experienced depressed mood, suicidal thoughts or aggressive and erratic behaviour. These reports included people both with and without pre-existing psychiatric illness. Varenicline may have caused these symptoms as a rare side effect, but it can be difficult to tell the difference between the side effects of varenicline and withdrawal from smoking.

Varenicline can also cause drowsiness, so it is important to take care when you are driving or operating machinery until you know how varenicline affects you.

Ms Kaye said people should read the Consumer Medicine Information (CMI) sheet about this medicine or any medicine that is new to them. The CMI is available from doctors and pharmacists.

Expert opinion continues to support the view that although quit-smoking medicines may help they are not an instant cure. Counselling programs and support for smoking cessation are key to successfully quitting.

“There are many ways to quit smoking, and different methods work for different people. Stick with it – eventually you will find a method that will work for you. It may take more than one attempt to be successful so exercise your will power and seek support – behaviour change is key to quitting,” she says.

Quitting at any time helps – the health of people who quit starts to improve within days.

Approaches to quit smoking include: going cold turkey, gradually reducing then quitting, getting counselling and using nicotine replacement therapy or other medicines.

Information about varenicline is available in NPS publication Medicine Update, a newsletter for consumers at www.nps.org.au/consumers, and in NPS RADAR, a drug bulletin for health professionals at www.nps.org.au/radar.

Medicine Update helps answer some of questions that are commonly asked about medicines when they first become available through the PBS.