All medicines have benefits and risks. Champix has been shown be an effective aid for quitting smoking, but like all medicines it is known to have side effects, some of which can be serious. The decision to use a particular medicine should be made after discussion between the patient and the prescribing doctor, and include discussion of the relative risks and benefits of the therapy compared to other possible treatments or no treatment at all. For medicines such as Champix that have shown benefit in assisting individuals to quit smoking, the health risks of continued smoking also need to be taken into account.
Prescription medicines such as Champix are required to have a Product Information (PI) document approved by the Therapeutic Goods Administration (TGA) and a Consumer Medicine Information (CMI) document to provide information to health care professionals and consumers about the safe and effective use of the medicine. Full versions of PIs and CMIs are available to the public and health care professionals on the TGA website and pharmacists can also provide this information to consumers.
Once a prescription medicine has been approved for use in Australia, the TGA continually monitors the safety of that medicine, and the PI and CMI are updated as new information becomes available. Therefore, a number of different versions of the PI and CMI for Champix have been published since Champix was first approved for use in Australia.
The Australian PI was updated in 2015 to make information about psychiatric symptoms more prominent. Subsequently an update to health care professionals was provided in February 2016 stressing the importance of advising patients and their families to stop treatment with varenicline and immediately contact either the prescribing doctor or another health care professional if such symptoms are experienced or observed. The PI was again updated in March 2017, with additional clinical trial and adverse effect data from a neuropsychiatric safety study in patients with and without a history of psychiatric disorders.
Medicine safety is often reassessed by regulators during the period the medicine is marketed. It should be noted that the US Food and Drug Administration removed the requirement for a black box warning for Chantix (the US equivalent of Champix: generic name varenicline) in December 2016.
This removal followed a review of updated clinical trial data that clarified the risk of serious psychiatric side effects with Chantix. The warning has never been on the pack itself but in the product information equivalent. Similarly, the European Medicines Agency lifted the warning regarding neuropsychiatric side effects with varenicline in May 2016, however the product information in the USA and Europe still mention these risks, as does the Australian PI.
Page 12 of the current Australian PI includes a bolded section which reads:
Page 3 of the current Australian CMI includes a bolded section which reads:
The TGA has processes in place for ensuring ongoing medicine safety through monitoring and investigating adverse event reports. The reporting of adverse events helps to build a detailed profile of the safety of medicines available in Australia. Adverse events reported to the TGA are also de-identified and then included in a publically available database, the Database of Adverse Events Notifications (DAEN). Significant safety concerns identified through this process are evaluated as part of ensuring product safety in the Australian community. It is important to be aware that the fact that an adverse event has been recorded in the DAEN does not necessarily mean the adverse event was caused by the medicine. The adverse event can be due to underlying illness or other factors, or it may be a coincidence that the adverse event occurred when the medicine was taken. The DAEN also does not include information about the benefits of the medicine, so the search results cannot be used to determine if the benefits of taking the medicine outweigh the risks.