COLUMBUS, Ohio – A drug used to help control psychotic behavior in people with schizophrenia holds promise for controlling similar symptoms in the early stages of Alzheimer's disease, a new study suggests.
What sets this drug – called quetiapine – apart from its contemporary counterparts is its apparent lack of serious side effects, such as confusion, muscle stiffness and imbalance in the joints, said Douglas Scharre, a study co-author and an associate professor of clinical neurology at Ohio State University.
None of the 10 subjects in the study reported any of these symptoms during a 12-week trial.
"Quetiapine should be considered the first line of treatment for psychosis in Alzheimer's patients because of its lack of serious side effects," Scharre said, adding that while no antipsychotic medication is currently approved by the Food and Drug Administration to treat Alzheimer's-related psychosis, physicians can prescribe it as an "off-label" use. An estimated 4 million people in the United States have the disease.
The research appears in a recent issue of the journal Alzheimer Disease and Associated Disorders.
Scharre and co-author Shu-Ing Chang, a clinical instructor of neurology at Ohio State, prescribed quetiapine (brand name Seroquel) to patients with mild to moderate forms of Alzheimer's disease. Their study is the first to look at the effects quetiapine may have on cognitive function in the disease.
The researchers recruited 10 outpatients with a diagnosis of probable Alzheimer's disease and who had symptoms of psychotic or aggressive behaviors severe enough to justify drug treatment on a regular basis. Quetiapine was the only antipsychotic medication prescribed during the 12-week study.
The researchers evaluated the subjects at the beginning of the study and again at six and 12 weeks. They measured behavioral symptoms using the Neuropsychiatric Inventory and evaluated cognitive abilities using the Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog). The patients also underwent a physical examination at each visit. Subjects were monitored weekly via telephone conversations.
The subjects began the study by taking 25 milligrams of quetiapine each night at bedtime. Dosages were increased by 25 mg weekly if symptoms of aggression and psychosis were still evident.
The average dose of quetiapine at the end of the study was 50 mg twice daily. Dosing ranged from 50 mg to 150 mg per patient per day, a fraction of what is normally required to control psychotic behavior in schizophrenic patients.
"Schizophrenics don't show much of a response until the dose is 150 mg or higher, and may require up to 600 to 800 mg of quetiapine to ease psychotic symptoms," Scharre said.
At the end of the current study, quetiapine at the 50 to 150 mg level did not significantly worsen cognitive function in the Alzheimer's subjects. In fact, the average ADAS-cog scores improved slightly after six weeks.
"The decrease in aggression and psychotic behavior at this point may also have contributed to the improvement in cognitive scores," Scharre said.
However, at week 12 the cognitive scores decreased slightly from what they were at the outset of the study. This most likely represents the natural result of the disease progression, and not the use of quetiapine, Scharre said.
The average Alzheimer's patient in the early to middle stages of the disease will usually show a decrease in cognition of five to 11 points annually on the ADAS-cog scale, or about one to three points every three months. The cognition of the subjects in the current study decreased an average of 2.4 points during the 12-week study.
As for physical side effects induced by quetiapine, four out of the 10 patients in the current study reported feeling drowsy at times, but the side effect was temporary. Four of the 10 patients also gained an average of four pounds while taking the drug, which might be a welcome side effect as weight loss is a common problem in Alzheimer's patients.
The subjects didn't report feeling dizzy nor did they complain of stiff joints or muscles. That's important, Scharre said, as people with the disease are elderly and prone to falling.
"While many of the currently available medications work well in controlling psychosis, they can cause confusion or Parkinson's disease-like symptoms, such as increased stiffness and tremor."
While he uses quetiapine to help control psychotic behavior in patients at all stages of the disease, Scharre said it's particularly important for patients in the early stages of Alzheimer's to take medications – such as quetiapine – that don't increase cognitive loss.
"A physician hopes to help patients retain as much cognitive function as possible, in a disease where cognitive decline is the norm," he said.
Materials provided by Ohio State University. Note: Content may be edited for style and length.
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