April 3, 2006
The drug Aricept, taken by many older Americans with Alzheimer's to boost memory and thinking during the early to mid stages of the disease, caused an unusual number of deaths in one recent study, raising concerns that the medication may be unsafe. While the findings were unsettling and require further investigation, many experts caution that numerous previous studies confirm that Aricept remains acceptably safe for the treatment of Alzheimer's disease.
Anyone who is currently taking Aricept or related Alzheimer's drugs, such as Razadyne and Exelon, should not panic and stop taking the medication on their own. Rather, as with any medication, they should discuss the risks and benefits with their doctor.
The current study, conducted in Japan, involved 648 men and women who were taking Aricept (which goes by the medical name donepezil) to treat vascular dementia, a form of memory loss caused by poor flood flow in the brain. This condition differs from Alzheimer's disease both in terms of its causes and its effects on the brain. After 24 weeks, 11 people who were taking the drug, or 1.7 percent, died. In comparison, there were no deaths among 326 study participants who were taking a placebo pill.
The difference in the death rates was surprising, as previous studies have shown that Aricept is not more likely to cause deadly complications than a dummy pill. Furthermore, it was unusual that there were no deaths in the placebo group. During any study, and especially one involving older people with serious illnesses such as heart and blood vessel disease, some deaths would be expected. Overall, the number of deaths in the Aricept group was not unusually high. Rather, the zero fatalities among the group taking a placebo appeared to be unusually low.
It is possible that the differences in death rates may have been due to random chance, though statistical analysis suggests that is not the case. Further investigation is warranted to determine if Aricept or related drugs may pose undue risks in those with Alzheimer's disease or other forms of dementia.
Still, experts caution that nobody taking Alzheimer's drugs should stop taking them on their own. Aricept was approved by the Food and Drug Administration for the treatment of mild to moderate Alzheimer's disease in 1994, after extensive testing in thousands of patients showed that the drug offered benefits and did not pose undue risks. Several large studies since then have not noted an increased risk of serious or deadly side effects in people taking the drug.
For more on Aricept and the treatment of Alzheimer's disease, visit www.ALZinfo.org.
News release, Eisai Co. Ltd Japanese makers of the drug Aricept. US Food and Drug Administration.