Alzheimer's disease (AD) is a progressive brain disease that causes slow and irreversible destruction of memory, language and thinking abilities. Over time, it also causes profound emotional and personality changes and loss of independence. Four drugs are approved by the Food and Drug Administration (FDA) for the treatment of cognitive symptoms related to Alzheimer's disease. Other medications, such as antidepressants, anti-anxiety drugs and antipsychotics, are also available to treat the behavioral symptoms associated with AD.
Cholinesterase Inhibitors
Cholinesterase inhibitors are drugs that boost the amount of the neurotransmitter acetylcholine in the brain. They are used in the treatment of Alzheimer's disease in an effort to slow down the process of cognitive decline. Three cholinesterase inhibitors have been approved by the FDA for treating AD: donepezil, rivastigmine and galantamine. Rivastigmine and galantamine are used to treat individuals with mild-to-moderate AD, while donepezil may be prescribed to those with mild-to-moderate or moderate-to-severe Alzheimer's. According to the National Institute on Aging, no single clinical research study has compared the effectiveness of these three drugs; however, because they all work in essentially the same way, there is no reason to suspect any one drug is significantly better than another (although there may be individual differences in responses to each drug). None of these drugs will cure AD, and, according to the Mayo Clinic, up to 50 percent of patients who take cholinesterase inhibitors show no improvement and may experience bothersome side effects, such as nausea, vomiting and diarrhea.
Memantine
Memantine was the first drug approved by the FDA for the treatment of moderate-to-severe Alzheimer's disease. According to the Mayo Clinic, it may be used alone or in combination with other drugs approved for AD. It works by blocking the toxic effects of excess glutamate, a neurotransmitter associated with degenerative brain diseases, in the brain. Common side effects may include dizziness, agitation and delusional behavior.
Antidepressants and Anxiolytics
Low doses of antidepressants and anxiolytics, or anti-anxiety drugs, may be given to target specific behavioral symptoms in Alzheimer's patients, including low mood, irritability, restlessness and sleep disturbances. Antidepressants that may be prescribed include citalopram, paroxetine, fluoxetine, sertraline and trazodone, while lorazepam and oxazepam are commonly administered anxiolytics, according to the Alzheimer's Association. Sleeping pills can have serious side effects on individuals with Alzheimer's disease. To avoid these negative effects, physicians may substitute anti-anxiety drugs or the antidepressant trazodone to improve sleep patterns.
Antipsychotic Drugs
Antipsychotic medications are available to treat symptoms of hallucinations, delusions, hostility and aggression or uncooperativeness. However, these drugs are not approved by the FDA for use with AD patients in treating these symptoms, because there is some evidence that antipsychotics may slightly increase the risk of death among older dementia patients, according to the Alzheimer's Association. If advisable, antipsychotics that may be prescribed include atypical antipsychotics, such as aripiprazole, quetiapine, risperidone, olanzapine and ziprasidone, and an older type of antipsychotic called haloperidol.
