Swiss pharmaceutical group Roche announced Wednesday a major recall of its anti-HIV drug Viracept after discovering a contamination in tablets.
recalls in Europe and some other world regions all batches of Viracept powder and tablets," the group said in a statement.
It said that the United States, Canada and Japan were not affected by the recall.
"Roche has received several reports that some batches of Viracept 250 mg tablets have a strange odour.
"A detailed chemical analysis of the affected tablets showed they contain higher than normal levels of methanesulfonic acid ethyl ester." Roche, which said the abnormal level of the substance was a "chemical impurity," advised patients to contact their doctors to discuss alternative therapies.
Viracept was introduced by Roche in 1998.