There are no good drugs to treat dementia and doctors just need to try them in a hit-or-miss fashion to try to help patients, according to new guidelines.
Experts who tried to set up treatment guidelines were disappointed to find no good options for patients with dementia, and no way to determine which drug might be best for certain cases.
"There is no cure for dementia and many of the drugs ... are being prescribed without evidence," Dr Amir Qaseem of the American College of Physicians, who led the study, said in a telephone interview.
"The benefits of therapy may be very modest."
Qaseem and colleagues at the American Academy of Family Physicians reviewed the results of 96 different studies of five different drugs approved for treating dementia.
Four are in a class of drugs called cholinesterase inhibitors - Pfizer and Eisai Co Inc's Aricept; galantamine, sold generically and under the brand names Razadyne, Reminyl and Nivalin; rivastigmine, sold by Novartis AG under the brand name Exelone; and tacrine, marketed to combat Alzheimer's disease under the brand name Cognex.
The fifth drug, memantine, is known as a neuropeptide-modifying agent and is sold by Forest Laboratories under the brand name Namenda.
Meds delay progression
The drugs can sometimes delay progression of the symptoms of dementia, which can take many different forms.
None work very well for people in general, although individual patients may see benefits, Qaseem said.
"There is so much variation between individual patients," he said. And if doctors keep trying one drug after another, weeks and months can pass. In the end, he said, "there might not be any effect at all."
Writing in the Annals of Internal Medicine, Qaseem and colleagues said they looked for evidence that the drugs helped cognition, global function, behaviour, mood and quality of life.
Rather than trying to find the most effective drug, doctors should focus on tolerability, adverse effects, ease of use and cost, they recommended.
"Doctors, patients and family care-givers desperately want information on how to treat this disease," Qaseem said.
Lack of meds a problem
"It is disheartening to find out that all we have to work with is these five drugs, and the evidence on these is scant. Consider that in 50 years, one in 45 Americans will suffer from Alzheimer's disease. This is huge problem."
Drugs need to be tested head to head, the committee said, and combinations also should be tested.
"More research is warranted because the available evidence concerning these pharmaceuticals' effects on quality of life is mixed and the clinical significance of many of the findings is questionable," said Dr. Kenneth Schellhase of the family physicians group.
The US National Institutes of Health estimates that 2.4 million people have Alzheimer's disease and another 1 million have some other form of dementia in the United States, although advocacy groups put the figure at 5 million. – (Maggie Fox/Reuters Health)
Description of dementia
Dementia = death within 5 years?