New York: The European Medicines Agency on Friday issued new warnings to doctors and patients about cases of suicidal thoughts linked to the smoking-cessation pill, sold as Champix in Europe and Chantix in the United States. The agency has directed Pfizer to submit changes to the product's marketing information before Dec. 19.

European Union's medicine authority has begun investigating the safety of the drug, following the reports of depression and suicide in patients taking the anti-smoking drug Champix.

The US regulators issued a warning about Chantix last month, after the reports of suicidal thoughts and behavior and at least one death potentially linked to the medication came out.

However, Pfizer, the world's largest drugmaker, said that there is no scientific evidence linking its drug to the reported events, although it is working closely with the European watchdog to review case histories.
The Pfizer's drug has been approved in the United States to treat advanced kidney cancer and stomach cancer.

According to the new analysis conducted by researchers at Children's Hospital Boston, the Dana-Farber Cancer Institute in Boston and Thomas Jefferson University in Philadelphia, nearly half of 75 patients with rare gastrointestinal tumors who took the drug in a clinical trial developed high blood pressure, 8 percent developed heart failure, and two patients had heart attacks.

According to the researchers, the patients taking the drug -- and especially those with heart risks -- should be closely monitored.

Responding to the analysis, Pfizer said that larger studies of Sutent showed lower incidence of heart effects, including heart failure, high blood pressure and reduced pumping function. It said safety risks are noted in the product's package insert label and that cardiac monitoring is suggested in patients with cardiac risk factors.