• Posted June 21, 2023

What Medications Are Used to Treat Alzheimer's?

While there is no cure for Alzheimer's, there are medications that can help ease symptoms and slow the progression of this devastating disease.

Alzheimer's disease is the most common type of dementia, affecting over 5.8 million Americans, according to the U.S. Centers for Disease Control and Prevention. Typically affecting older individuals, it begins with mild memory loss and eventually leads to the inability to carry on a conversation or respond to their environment. Here, experts break down the most common Alzheimer's disease medications, including the types, how they work and their most common side effects.

Brexpiprazole (Rexulti)

The U.S. Food and Drug Administration recently approved the drug brexpiprazole (Rexulti) for treating the agitation associated with Alzheimer's disease.

“Agitation is one of the most common and challenging aspects of care among patients with dementia due to Alzheimer's disease. ‘Agitation' can include symptoms ranging from pacing or restlessness to verbal and physical aggression,” Dr. Tiffany Farchione, director of the division of psychiatry in the FDA's Center for Drug Evaluation and Research, said in an agency news release announcing the approval. “These symptoms are leading causes of assisted living or nursing home placement and have been associated with accelerated disease progression.”

Initially, the medication is started as a 0.5 milligram (mg) pill and slowly upped over 15 days to a target dose of 2 mg daily.

Common side effects of brexpiprazole, according to the Mayo Clinic, include:

• Belching
• Headache
• Heartburn
• Inability to sit still
• Indigestion
• Muscle aches
• Need to keep moving
• Restlessness
• Sleepiness or unusual drowsiness
• Stomach discomfort, upset or pain
• Stuffy or runny nose
• Weight gain

Lecanemab (Leqembi)

The FDA recently approved the Alzheimer's drug lecanemab (Leqembi), an immunotherapy that addresses the underlying biology of the disease and is used for mild cognitive impairment. The Alzheimer's Association reports that this drug helps slow the disease's progression, allowing individuals to live independently for longer. According to Yale Medicine, "Lecanemab works by removing a sticky protein from the brain that is believed to cause Alzheimer's disease to advance.”

Your health care provider will test you for confirmation of elevated beta-amyloid before prescribing. The drug is administered intravenously (IV) every two weeks.

Common side effects of lecanemab, reported by Yale Medicine, are:

• Infusion-related reactions, including flushing, chills, fever, rash and body aches
• Amyloid-related imaging abnormalities (ARIA) or fluid on the brain (usually asymptomatic)
• Brain bleeding, typically microhemorrhages; people with Alzheimer's are typically more susceptible to this; however, a severe bleed is rare

Aducanumab (Aduhelm)

The Journal of the American Medical Association reports that aducanumab (Aduhelm), an immunotherapy that was approved by the FDA in 2021, has been shown to reduce amyloid plaque deposits in the brain. However, it has not been shown to make any clinical difference in the symptoms of the disease. It is used for mild cognitive impairment and administered intravenously every four weeks.

Common side effects, according to the National Institute on Aging (NIA), include:

• ARIA
• Headaches
• Dizziness
• Diarrhea
• Falls
• Confusion

Donepezil (Aricept)

Donepezil is a cholinesterase inhibitor for treating mild, moderate and severe Alzheimer's disease. It works by preventing the breakdown of acetylcholine in the brain, which improves attention, memory and the ability to engage in daily activities, per the Cleveland Clinic.

This medication is taken at bedtime, starting at 5 mg for the first four to six weeks, then increasing to 10 mg per night or up to 23 mg per night for moderate to severe disease. Donepezil is also available as a transdermal patch.

Common side effects, according to the Cleveland Clinic, include:

• Allergic reactions
• Peptic ulcer
• Seizures
• Slow heartbeat
• Stomach bleed
• Difficulty urinating
• Diarrhea
• Fatigue
• Muscle pain or cramps
• Nausea
• Trouble sleeping

Rivastigmine (Exelon, Nimvastid, Prometax)

Rivastigmine is a cholinesterase inhibitor for treating mild and moderate Alzheimer's disease. It works by preventing the breakdown of acetylcholine and butyrylcholine in the brain. It may help with cognitive and behavioral symptoms.

Per the NIA, the drug is taken twice a day as a capsule or once daily through a skin patch.

Common side effects are:

• Nausea
• Vomiting
• Diarrhea
• Weight loss
• Indigestion
• Decreased appetite
• Anorexia
• Muscle Weakness

Galantamine (Razadyne)

Galantamine is a cholinesterase inhibitor for treating mild and moderate Alzheimer's disease. It works by preventing the breakdown of acetylcholine and stimulates nicotinic receptors to release more acetylcholine per the NIA. It may also help with cognitive and behavioral symptoms.

It is taken orally twice a day, by capsule or solution or daily as an extended-release capsule.

The NIA lists the following side effects:

• Dizziness
• Headache
• Diarrhea
• Constipation
• Confusion

Memantine (Namenda)

Memantine is an N-methyl-D-aspartate (NMDA) antagonist used to treat moderate to severe Alzheimer's disease. Per StatPearls, it works by slowing the neurotoxicity of the disease.

It is taken by tablet or capsule and increased from 5 mg to 20 mg over four weeks.

Common side effects, according to StatPearls, are:

• Dizziness
• Headache
• Confusion
• Diarrhea
• Constipation

There is concern that the drug can worsen the symptoms of dementia; the patient should be closely monitored.

Of note, memantine and donepezil (Namzaric) are often prescribed in combination, as they have different mechanisms of action.