No medication prescribed for dementia is better than others and some patients may not benefit from any of the drugs, concludes a review that is part of new guidelines for U.S. doctors.
The guidelines come from the American College of Physicians and the American Academy of Family Physicians and are published in the Annals of Internal Medicine.
Doctors from both groups reviewed 96 studies on five drugs approved for treating dementia. The medications were:
- donepezil, sold under the name of Aricept
- galantamine, sold in Canada generically and under the brand name Reminyl. Sold in the U.S. as Razadyne, and Nivalin;
- rivastigmine, sold in Canada under the name Exelon. Sold in the U.S. as Exelone
- tacrine, which is not available for use in Canada but it marketed in the U.S. under the name Cognex.
- memantine, sold in Canada under the name Ebixa. Sold as Namenda in the U.S.
The first four are in a class of drugs called cholinesterase inhibitors; the fifth is known as a neuropeptide-modifying agent.
The drugs are not a cure for dementia but can sometimes slow the progress of the disease, which causes lapses in memory and clear thinking and may lead to personality changes.
After focusing in on 59 studies, the researchers found that the benefits of any of the drugs may be modest at best.
They found that most of the studies showed some improvements in measures of thinking and memory. But the improvements were generally so small that they likely wouldn't lead to important improvements in the daily lives of patients and their caregivers.
That said, a subgroup of patients seem to react well to the medications, the authors note, but they add that currently, doctors have no way to predict which patients might have a favourable response.
Therefore, the doctors say they don't recommend prescribing these medications for every patient with dementia.
The authors note that the studies found that most of the drugs carried side effects, such as nausea, with tacrine presenting the most side effects, according to the studies they reviewed.
The review concludes that if doctors and caregivers decide to use medications for dementia, they should consider side effects, ease of use, and cost when choosing from the drugs, since the studies weren't able to identify a clear winner among them.
Much more research on the medications is needed, the reviewers add, including research that compares the drugs need head to head, as well as in combination.
More than 26 million people worldwide have Alzheimer's disease, the most common cause of dementia, and experts expect that number will quadruple by 2050. At that rate, one in 85 people will have the brain-destroying disease in 40 years.
