A specific dose of Alzheimer’s drug should be pulled from the market because it poses a risk to patients, according to a consumer group.
The drug, donepezil, sold under the brand Aricept, is administered in several doses – the highest being 23 milligrams – for patients with moderate to severe Alzheimer’s disease.
It is prescribed to improve mental function, such as memory, attention and reasoning by increasing a brain chemical. Aricept which is taken daily, could slow the mental decline, but it does not cure or prevent Alzheimer's.
The Public Citizen’s Health Research Group called the 23-milligram dose of Aricept “significantly more toxic” than the 10-milligram dose and said it “should be immediately withdrawn from the market.”
The group says that the drug in higher dose compared with the 10-milligrams could pose increased adverse effects such as slowed pulse rate, nausea, vomiting, diarrhea, urinary incontinence, fatigue, dizziness and agitation. The group also said the higher dose does not appear to give any benefits to the patients.
Three stages of Alzheimer's
Patients often stop taking the higher dose because of its strong side effects such as vomiting. And Alzheimer’s patients are particularly sensitive to vomiting because it can lead to other problems such as pneumonia, massive gastrointestinal bleeding, esophageal rupture and even death, the group said.
In response, Pfizer, which co-promotes Aricept with another company, Eisai, wrote in an emailed statement: "We are reviewing the petition and will respond accordingly; however, it is important to note that the Aricept (donepezil HCl) 23 mg tablet has been approved by the U.S. Food and Drug Administration for the treatment of moderate-to-severe Alzheimer’s disease. "
Dr. James Lah, director of the cognitive neurology program at Emory University"s Department of Neurology, regularly prescribes Aricept to patients, but doesn't prescribe the 23-milligram dose.
“Being Americans, the notion is that bigger is better, more is better... it’s simply not true in this particular instance,” Lah said.
He said he was concerned when the FDA approved the 23-milligram version.
“There is very little evidence that it’s superior,” Lah, an Alzheimer's clinician and associate professor said. “There is a lot of evidence that it’s worse in terms of causing side effects. If you look at the one study, only one clinical trial reported about the 23 versus 10 milligram Aricept. The results were entirely mixed in terms of effectiveness.”