Donepezil, also known by its brand name Aricept, appears to double the risk of hospitalization for a painful muscle condition, according to a new Canadian study.
Rhabdomyolysis is muscle tissue breakdown that causes the release of muscle fiber contents into the blood. Left untreated, it can result in kidney disease. Agencies in several countries, including Canada, warn about a possible link with donepezil. In the United States, the Food and Drug Administration has mentioned unsubstantiated reports of an association, though no warning to date.
The new study followed 220,000 patients aged 66 years or older in Ontario, Canada, who had prescriptions for donepezil or one of two other popular dementia drugs: rivastigmine or galantamine. All three medications are cholinesterase inhibitors, used to manage dementia symptoms such as memory loss and thinking problems.
When compared with the other drugs, donepezil was associated with a two-fold higher risk of hospitalization for rhabdomyolysis. The relative risk was small – 0.06% incidence in the population studied – but statistically significant, reported Jamie Fleet, M.D., McMaster University, Hamilton, Ontario.
The findings “support regulatory agency warnings about the risk of donepezil-induced rhabdomyolysis,” said Fleet, in a statement. But most hospital admissions with rhabdomyolysis after donepezil use were not severe, and no patient was treated with acute dialysis or mechanical ventilation, she added. “Reassuringly, the 30-day incidence of a hospital admission with rhabdomyolysis after initiating donepezil remains low.”
The study was published this week in the Canadian Medical Association Journal (CMAJ).
