Treatments for Alzheimer’s Disease

There is currently no cure for Alzheimer’s disease, but drug and nondrug treatments may help manage symptoms.

Alzheimer’s disease causes a gradual decline in memory, thinking, and other cognitive function.

People with Alzheimer’s dementia are increasingly unable to meet the demands of daily life. During the final stage of the disease, they become fully reliant on others for care.

While there is no way to stop the progression of the disease, there are medicines that can help sharpen the mind for a short while.

Five drugs approved by the Food and Drug Administration (FDA) slow worsening of symptoms for about 6 to 12 months, on average, for about one-half the people who take them. (1)

The medication memantine (Namenda), for instance, may help people with later-stage Alzheimer’s maintain the ability to use the bathroom independently for several extra months. (2)

Other drugs can improve behavioral symptoms of Alzheimer’s dementia, like depression and aggression, offering relief to both patients and caregivers.

Before doctors prescribe medication for people with Alzheimer’s and other forms of dementia, they typically recommend nondrug treatments. These may include:

• Talk therapy, such as sessions with a mental health counselor or meetings with a support group, to cope with the emotional challenges of this diagnosis
• Cognitive behavioral therapy, a type of psychotherapy, to counter depression and anxiety
• Cognitive stimulation therapy, to keep the mind active with themed activity sessions that challenge the brain
• Cognitive rehabilitation, to relearn lost skills or develop new compensating skills
• “Life story work” — telling or documenting personal experiences and memories, to improve mood, well-being, and mental function
• Singing, dancing, art, and other activities that keep patients physically, mentally, and socially engaged, to boost confidence and cognitive skills and lower anxiety (3)

Can Exercise Make a Difference?

There is some evidence that exercise can help prevent and treat Alzheimer’s.

In one study, subjects with early-stage Alzheimer’s disease took part in a supervised exercise program involving 150 minutes of walking per week. After six months, some — but not all — of the subjects performed better on tests measuring memory and thinking skills. These subjects also showed a slight increase in brain size. (4)

These are the five drugs approved by the FDA to treat cognitive symptoms of Alzheimer’s:

• donepezil (Aricept)
• galantamine (Razadyne)
• rivastigmine (Exelon)
• memantine (Namenda)
• donepezil and memantine (Namzaric)

Donepezil, galantamine, and rivastigmine belong to a class of drugs called cholinesterase inhibitors and are prescribed for mild to moderate Alzheimer’s dementia.

Cholinesterase inhibitors are thought to help with cognitive symptoms by preventing the breakdown of acetylcholine, a neurotransmitter (chemical messenger) in the brain that’s believed to be important for memory and thinking.

Since the brain produces less acetylcholine as the disease progresses, these drugs may become less effective over time.

Other potential problems are side effects, such as nausea and vomiting, loss of appetite and weight loss, and diarrhea.

Doctors may prescribe memantine for severe Alzheimer’s. This drug is an N-methyl D-aspartate (NMDA) antagonist believed to work by regulating another neurotransmitter called glutamate that is important for learning and memory.

But excessive amounts of glutamate, as in brains with Alzheimer’s disease, can cause cell damage and death.

Side effects of memantine include headache, constipation, diarrhea, confusion, and dizziness.

The combination of memantine and donepezil (a cholinesterase inhibitor) is used to treat moderate-to-severe Alzheimer’s. (2)

Other drugs — including antidepressants, anticonvulsants, antipsychotics, anti-anxiety drugs, and sleep aids — are sometimes used to treat behavioral problems associated with Alzheimer’s disease.

When counseling, support groups, or other nondrug methods don’t help with depression or anxiety, doctors may prescribe one of the following drugs:

• citalopram (Celexa)
• mirtazapine (Remeron)
• sertraline (Zoloft)
• bupropion (Wellbutrin)
• duloxetine (Cymbalta)
• imipramine (Tofranil)
• escitalopram (Lexapro)

Because of potentially dangerous side effects, doctors prescribe other drugs with extreme caution.

Insomnia can be a problem for some people with Alzheimer’s, but sleep aids such as zolpidem (Ambien) can cause confusion and lead to falls.

Antipsychotics like risperidone (Risperdal) can increase the risk of death in some older people with dementia, so doctors prescribe them only as a last resort to alleviate severe hallucinations, paranoia, agitation, and aggression. (2)

Benzodiazepines, such as diazepam (Valium), should also be generally avoided in patients with Alzheimer’s disease. There is also some research that shows a correlation between benzodiazepine use and an increased risk of being diagnosed with Alzheimer’s.

Several new Alzheimer’s treatments are currently being investigated.

Experimental new treatments typically target two hallmarks of the disease: amyloid plaques (abnormal clumps of the protein fragment beta-amyloid) and tau protein tangles inside brain cells.

Scientists are studying the enzymes that clip beta-amyloid from its parent compound, amyloid precursor protein (APP). They are also looking at the pathways by which those beta-amyloid fragments form into plaques, hoping to develop medication that interferes with these processes.

Researchers are also exploring the potential of immunotherapy, working to develop antibodies against beta-amyloid that can remove plaque from the brain. (6)

In 2021, the FDA approved aducanumab (Aduhelm), a monoclonal antibody drug that targets the beta-amyloid clusters that turn into plaque. It is the first infusion treatment the FDA has approved for Alzheimer’s. Unlike other FDA-approved drugs that have demonstrated clinical slowing of the disease, aducanumab has been shown to reduce beta amyloid plaques in the brain. However, aducanumab does not reverse the progression of Alzheimer’s for those who have already developed symptoms, and there was some controversy surrounding the FDA’s approval around the scientific evidence for its effectiveness.

Drugs in the Clinical-Trial Pipeline

Some Alzheimer’s drugs under investigation include:

• JNJ-54861911 This drug blocks one of the enzymes that makes beta-amyloid. It is in phase 3 trials to see if it slows cognitive decline in people who have elevated levels of beta-amyloid in the brain but do not have Alzheimer’s symptoms. Results are expected in 2024. (6)
• AADvac1 This is a vaccine that prompts the body’s immune system to go on the offense against an abnormal form of tau protein. A two-year phase 2 trial was completed and demonstrated safety and an immunogenic response against the abnormal tau protein in Alzheimer’s. Larger studies are needed to demonstrate clinical benefit.