Alzheimer's still has no cure, but two types of drugs can help manage symptoms of the disease.

By Mayo Clinic Staff

Learning you have Alzheimer's disease can be devastating. Working with your health care team can help you find the best strategies to manage your symptoms and prolong your independence.

Alzheimer's drugs might be one strategy to help you temporarily manage memory loss, thinking and reasoning problems, and day-to-day function. Unfortunately, Alzheimer's drugs don't work for everyone, and they can't cure the disease or stop its progression. Over time, their effects wear off.

Research into more-effective Alzheimer's drugs is ongoing. If you can't take the approved medications or they don't work for you, ask your doctor if you might be eligible for a clinical trial.

The Food and Drug Administration (FDA) has approved two types of drugs specifically to treat symptoms of Alzheimer's disease.

  • Cholinesterase inhibitors
  • Memantine

These drugs:

  • Are approved for specific Alzheimer's stages. These stages — mild, moderate and severe — are based on scores on tests that assess memory, awareness of time and place, and thinking and reasoning.

    Doctors might, however, prescribe Alzheimer's drugs for stages other than those for which the FDA has approved them. Alzheimer's stages aren't exact, individual responses to drugs vary and treatment options are limited.

    If your doctor prescribes medication as part of your Alzheimer's care plan, make sure you understand the drug's potential benefits and risks for your situation.

  • Are not approved for mild cognitive impairment (MCI). This condition, which involves subtle changes in memory and thinking, can be a transitional stage between normal age-related memory changes and Alzheimer's disease. Many people with MCI — but not all — eventually develop Alzheimer's or another dementia.

    Clinical trials testing whether Alzheimer's drugs might prevent progression of MCI to Alzheimer's have generally shown no lasting benefit.

One way Alzheimer's disease harms the brain is by decreasing levels of a chemical messenger (acetylcholine) that's important for alertness, memory, thought and judgment. Cholinesterase (ko-lin-ES-tur-ays) inhibitors boost the amount of acetylcholine available to nerve cells by preventing its breakdown in the brain.

Cholinesterase inhibitors can't reverse Alzheimer's disease or stop the destruction of nerve cells. These medications eventually lose effectiveness because dwindling brain cells produce less acetylcholine as the disease progresses.

Common side effects can include nausea, vomiting and diarrhea. Starting treatment at a low dose and working up to a higher dose can help reduce side effects. Taking these medications with food also might help minimize side effects.

People with certain types of cardiac arrhythmias shouldn't take cholinesterase inhibitors.

Three cholinesterase inhibitors are commonly prescribed:

  • Donepezil (Aricept) is approved to treat all stages of the disease. It's taken once a day as a pill.
  • Galantamine (Razadyne) is approved to treat mild to moderate Alzheimer's. It's taken as a pill once a day or as an extended release capsule twice a day.
  • Rivastigmine (Exelon) is approved for mild to moderate Alzheimer's disease. It's taken as a pill. A skin patch is available that can also be used to treat severe Alzheimer's disease.

Memantine (Namenda) is approved by the FDA for treatment of moderate to severe Alzheimer's disease. It works by regulating the activity of glutamate, a messenger chemical widely involved in brain functions — including learning and memory. It's taken as a pill or syrup. Common side effects include dizziness, headache, confusion and agitation.

The FDA has also approved a combination of donepezil and memantine (Namzaric), which is taken as a capsule. Side effects include headache, dizziness, nausea and diarrhea.

Because Alzheimer's is a progressive disease, your symptoms and care plan will change over time. If you're taking an Alzheimer's drug, ongoing review of your care plan will include working with your doctor to decide how long you should continue your medication.

Because the effects of Alzheimer's drugs are usually modest, it might be difficult to tell if the drugs are working. However, you can't know if your symptoms might be more severe without your medication.

Talk to your doctor before stopping an Alzheimer's drug, and let your doctor know if your condition worsens after you stop.

July 15, 2017