High doses of the Alzheimer's drug Aricept should be banned because they are no more effective than low doses and have a sharply increased risk of adverse effects, the advocacy group Public Citizen and a Johns Hopkins University geriatrician said Wednesday in a petition to the Food and Drug Administration. Aricept, known generically as donepezil, is one of the very few drugs available for treating Alzheimer's disease, but it provides only a very modest slowing in the cognitive and functional deficits associated with the disease. Yet the drug is widely used "due primarily to two factors: the understandable desperation of those who care for patients with Alzheimer's disease and a relentless promotional campaign by drug companies," said co-petitioner Dr. Thomas Finucane of Hopkins.
Aricept has been approved by the FDA in dosages of 5 to 10 milligrams for patients with mild to moderate cases of Alzheimer's and in a dose of 10 to 23 milligrams for more severe cases. The petition asks the FDA to ban the 23-mg version of the drug and to warn patients and physicians against taking two 10-mg. pills per day if the higher dosage is removed from the market.
Clinical trials of Aricept submitted to the FDA for approval show no significant benefit from the 23-mg version compared to the 10-mg version, the petition said. But the increased adverse effects from the higher dosage include a slowed pulse rate, nausea, vomiting, diarrhea, urinary incontinence, fatigue, dizziness, agitation, confusion and anorexia. Vomiting, which occurred more than 3 1/2 times more frequently in those taking the high dosage, is a particularly dangerous side effect for Alzheimer's patients, the petition says, because it can lead to pneumonia, massive gastrointestinal bleeding, esophageal rupture and even death.