The European Medicines Evaluation Agency is reviewing the anti-smoking drug Zyban.
The move comes after a rising number of deaths of patients who had taken the medicine. The agency said its scientific committee would examine the risks and benefits of the drug.
The review comes as the latest British government figures show the number of people who have died after taking Zyban has more than tripled in a year.
A total of 57 patients had died by January 10th this year in the UK following suspected adverse reactions to Zyban, the Medicines Control Agency (MCA) said last month. According to the MCA, around 500,000 people in the UK are estimated to have taken Zyban.
The drug was first licensed in June 2000. However, the MCA has stressed that any link between the medicine and deaths are unproven.
A spokesman for the European Medicines Evaluation Agency in London said today the review was expected to last between three and six months.
Germany officially requested a review into the medicine earlier this week amid concerns over its safety, he added.
A spokesman for GlaxoSmithKline, Europe's biggest drug maker, said today: "We have been notified the review is taking place.
"We remain extremely confident in the safety of Zyban and in its role in stopping smoking. In the UK alone, 320 people die each day of smoking related diseases."
PA