Champix is suspected of playing a major role in the deaths of 44 patients -- 30 of them by suicide -- since the popular stop-smoking drug was approved in Canada in 2007, a Vancouver Sun investigation has found.
The Pfizer drug has also been linked to more than 1,300 incidents of suicide attempts or thoughts, depression, and aggression/anger across the country in the past seven years.
The drug is the most popular of those offered by B.C.s quit smoking program, which traditionally sees a jump in participation every January as people renew new years resolutions to butt out.
Numbers on the deaths and other side-effects come from a Health Canada database where doctors, pharmacists and drug companies report bad side-effects experienced by patients taking pharmaceuticals.
But Health Canada admits on its website that side-effects are under-reported, and experts say the database could represent as little as one per cent of the patients who suffer complications.
A small proportion of the adverse reactions that have occurred on this drug in Canada would be in the adverse reaction database. Essentially it is spontaneous, voluntary reporting, said Barbara Mintzes, a pharmaceutical drug expert at the University of B.C.
Even the incomplete numbers, though, are a concern, she said. When someone taking an anti-depressant attempts suicide, its initially not clear whether thats caused by the pre-existing depression or the drug; but in the case of Champix, people are taking the drug to stop smoking -- not for a mental health condition.
You are looking at a lot of deaths, suicides and attempted suicides, and suicidal ideation in a population that you would have no reason to think would be otherwise at high risk of suicide, said Mintzes, an associate professor in the Faculty of Medicines School of Population and Public Health.
The Sun downloaded data from the Health Canada site for Champix and Zyban, the two drugs covered by Pharmacare as part of the provinces Smoking Cessation program.
Champix is the subject of a class-action lawsuit, which more than 200 Canadians have joined, alleging psychiatric side-effects. One of the plaintiffs is the mother of a B.C. woman who killed herself while she was on the drug.
In recent years, Champix has been slapped with the toughest safety warnings in the U.S. and Canada, and France stopped covering the drug through its public Pharmacare system.
In October, American consumer and health groups submitted a petition demanding the U.S. government further increase the warnings about Champix in relation to suicidal behaviour, aggression/violence, psychosis, and depression.
In November, the Drug and Poison Information Centre warned there were nearly 100 Zyban overdoses in B.C. in 2013, including 47 cases of suspected suicide attempts. The Health Canada database showed 27 deaths and the death of one fetus with Zyban as the suspected cause, since the drug was approved in Canada in 1998.
B.C. Health Minister Terry Lake was not available for an interview, but a spokesperson issued a statement that said B.C. decides which drugs to fund based on the best scientific evidence available. It also listed several reviews and research papers that found Champix and Zyban are effective and safe, and have helped many people quit smoking.
In October 2012, Health Canada reaffirmed that it considers the benefits of Champix, when used as directed on the label, to continue to outweigh the risks, said the email from ministry media relations manager Kristy Anderson.
In a statement to The Sun, manufacturer Pfizer said adverse reaction reports, such as those provided to Health Canada, do not necessarily prove the side-effect was caused by a drug because they are voluntarily submitted and may not contain patients full medical history. Pfizer also said quitting smoking can lead to depression, agitation or recurrence of a pre-existing mental health issue, regardless of whether the patient is taking a stop-smoking drug.
There is no reliable scientific evidence to demonstrate that Champix causes serious neuro-psychiatric events, said the statement provided by Pfizers Christina Antoniou. All medications have potential risks. The benefits and risks of all treatment options for quitting smoking should be part of the patient-physician dialogue before initiating treatment.
The federal government oversees drug approvals in Canada, and insists every death is considered serious and important.
Health Canada continuously monitors the safety of drug products on the market by using information from a variety of sources, such as adverse reaction data, medical and scientific literature and foreign regulatory agencies, spokesman Michael Valerio said in an email.
In each of the cases counted by The Sun, Champix was listed as the suspected cause of the adverse reaction; but Health Canada cautions that conclusion is only the opinion of the health professional or drug company making the report.
Other factors, such as the patients underlying medical condition, or other medications taken at the same time need to be considered as potential causes or contributing factors, Valerios email said.
B.C. spent $8.7 million in the fiscal year 2013/14 on its quit smoking program, including filling nearly 66,000 claims for Champix and 8,000 claims for Zyban. The program spending and prescriptions are down from the previous year, according to the Health Ministry, but a flurry of new patients are expected this month.
Nationally, there were 625,000 prescriptions filled for Champix and 38,000 for Zyban in 2013, according to IMS Brogan, an international company that collects health data. Health Canadas database shows 129 reports of adverse reactions to Champix and 13 to Zyban in 2013.
The data downloaded from Health Canada was difficult to use because there are many duplicate entries that required deletion. The Suns final analysis found that in the last seven years in Canada, in addition to the 44 deaths, there were about 350 reports of Champix causing suicide attempts or suicidal ideation, 30 reports of homicidal ideation, and 64 of amnesia. There were also approximately 600 reports of Champix causing depression, 230 of aggression, 180 of anger, and 150 of mental side-effects, including hallucinations and psychotic disorders.
