Drug regulators are being urged to reconsider the use of the anti-smoking drug Champix after a new study found an increased risk of heart attack and stroke for people using it.
A major international review of 14 trials of the drug varenicline, sold as Champix in New Zealand and Australia, found people taking the drug faced a 72% higher risk of serious cardiovascular problems compared with those who try other methods, the ABC reports.
Dr Sonal Singh, from Johns Hopkins School of Medicine in the United States co-authored the study, which was published in the Canadian Medical Association Journal.
Pfizer, the drug's manufacturer, responded to the accusations and critiqued the study's methodology, saying "the difference of 72 percent reported in the Singh analysis also needs to be put into appropriate context."
The drug firm said the actual difference in cardiovascular complaints between patients using Champix and those using a placebo reported in the study analysis was less than a quarter of 1%.