Treatment of Alzheimer's
Alzheimer’s disease is complex, and it is unlikely that any one drug or other intervention will successfully treat it. Current approaches focus on helping people maintain mental function, manage behavioral symptoms, and slow down the symptoms of disease.
Several prescription drugs are currently approved by the U.S. Food and Drug Administration (FDA) to treat people who have been diagnosed with Alzheimer’s disease. Treating the symptoms of Alzheimer’s can provide people with comfort, dignity, and independence for a longer period of time and can encourage and assist their caregivers as well.
Most medicines work best for people in the early or middle stages of Alzheimer’s. For example, they can slow down some symptoms, such as memory loss, for a time. It is important to understand that none of these medications stops the disease itself.
Treatment for Mild to Moderate Alzheimer’s
Medications called cholinesterase inhibitors are prescribed for mild to moderate Alzheimer’s disease. These drugs may help reduce some symptoms and help control some behavioral symptoms. The medications are Razadyne® (galantamine), Exelon® (rivastigmine), and Aricept® (donepezil).
Scientists do not yet fully understand how cholinesterase inhibitors work to treat Alzheimer’s disease, but research indicates that they prevent the breakdown of acetylcholine, a brain chemical believed to be important for memory and thinking. As Alzheimer’s progresses, the brain produces less and less acetylcholine; therefore, cholinesterase inhibitors may eventually lose their effect.
No published study directly compares these drugs. Because they work in a similar way, switching from one of these drugs to another probably will not produce significantly different results. However, an Alzheimer’s patient may respond better to one drug than another.
Treatment for Moderate to Severe Alzheimer’s
A medication known as Namenda® (memantine), an N-methyl D-aspartate (NMDA) antagonist, is prescribed to treat moderate to severe Alzheimer’s disease. This drug’s main effect is to decrease symptoms, which could allow some people to maintain certain daily functions a little longer than they would without the medication. For example, Namenda® may help a person in the later stages of the disease maintain his or her ability to use the bathroom independently for several more months, a benefit for both the person with Alzheimer's and caregivers.
The FDA has also approved Aricept®, the Exelon® patch, and Namzaric®, a combination of Namenda® and Aricept®, for the treatment of moderate to severe Alzheimer’s disease.
Namenda® is believed to work by regulating glutamate, an important brain chemical. When produced in excessive amounts, glutamate may lead to brain cell death. Because NMDA antagonists work differently from cholinesterase inhibitors, the two types of drugs can be prescribed in combination.
|Drug Name||Drug Type & Use||How It Works||Common Side Effects|
|Aricept® (donepezil)||Cholinesterase inhibitor prescribed to treat symptoms of mild, moderate, and severe Alzheimer's||Prevents the breakdown of acetylcholine in the brain||Nausea, vomiting, diarrhea, muscle cramps, fatigue, weight loss|
|Exelon® (rivastigmine)||Cholinesterase inhibitor prescribed to treat symptoms of mild to moderate Alzheimer's (patch is also for severe Alzheimer's)||Prevents the breakdown of acetylcholine and butyrylcholine (a brain chemical similar to acetylcholine) in the brain||Nausea, vomiting, diarrhea, weight loss, indigestion, muscle weakness|
|Namenda® (memantine)||N-methyl D-aspartate (NMDA) antagonist prescribed to treat symptoms of moderate to severe Alzheimer's||Blocks the toxic effects associated with excess glutamate and regulates glutamate activation||Dizziness, headache, diarrhea, constipation, confusion|
|Namzaric® (memantine and donepezil)||NMDA antagonist and cholinesterase inhibitor prescribed to treat symptoms of moderate to severe Alzheimer’s||Blocks the toxic effects associated with excess glutamate and prevents the breakdown of acetylcholine in the brain||Headache, nausea, vomiting, diarrhea, dizziness, anorexia|
|Razadyne® (galantamine)||Cholinesterase inhibitor prescribed to treat symptoms of mild to moderate Alzheimer's||Prevents the breakdown of acetylcholine and stimulates nicotinic receptors to release more acetylcholine in the brain||Nausea, vomiting, diarrhea, decreased appetite, dizziness, headache|
|Drug Name||Manufacturer's Recommended Dosage||For More Information|
||For current information about this drug's safety and use, read the prescribing information (PDF, 594K).|
||For current information about this drug’s safety and use, visit the FDA website. Click on "Search Drugs@FDA," search for Exelon, and click on drug-name links to see label information.|
||For current information about this drug's safety and use, visit the Namenda® website and the Namenda XR® website. Click on "Full Prescribing Information" to see the drug label.|
|Namzaric® (memantine and donepezil)||
||For current information about this drug’s safety and use, visit the Namzaric® website. Click on “Full Prescribing Information” to see the drug label.|
||For current information about this drug’s safety and use, visit the JanssenMD® website. Click on "Full Prescribing Information" to see the drug label.|
* Available as a generic drug.
Dosage & Side Effects of Alzheimer's Medications
Doctors usually start patients at low drug doses and gradually increase the dosage based on how well a patient tolerates the drug. There is some evidence that certain people may benefit from higher doses of the cholinesterase inhibitors. However, the higher the dose, the more likely side effects are to occur.
Patients should be monitored when a drug is started. All of these medicines have possible side effects, including nausea, vomiting, diarrhea, and loss of appetite. Report any unusual symptoms to the prescribing doctor right away. It is important to follow the doctor’s instructions when taking any medication, including vitamins and herbal supplements. Also, let the doctor know before adding or changing any medications.
Managing Behavioral Symptoms of Alzheimer's Disease
Common behavioral symptoms of Alzheimer’s include sleeplessness, wandering, agitation, anxiety, aggression, restlessness and depression. Scientists are learning why these symptoms occur and are studying new treatments—drug and nondrug—to manage them. Research has shown that treating behavioral symptoms can make people with Alzheimer’s more comfortable and makes things easier for caregivers.
Experts agree that medicines to treat these behavior problems should be used only after other strategies that don’t use medicine have been tried. Learn more about behavioral changes in people with Alzheimer's disease and ways to cope.
Medicines to Be Used with Caution in People with Alzheimer's Disease
There are some medicines, such as sleep aids, anti-anxiety drugs, anticonvulsants, and antipsychotics, that a person with Alzheimer’s disease should take only:
- After the doctor has explained all the risks and side effects of the medicine
- After other, safer non-medication options have not helped treat the problem
You will need to watch closely for side effects from these medications.
Sleep aids are used to help people get to sleep and stay asleep. People with Alzheimer’s disease should NOT use these drugs regularly because they make the person more confused and more likely to fall. There are lifestyle changes people can make to improve their sleep.
Anti-anxiety drugs are used to treat agitation. These drugs can cause sleepiness, dizziness, falls, and confusion. For this reason, doctors recommend they should only be used for short periods of time.
Anticonvulsants are drugs sometimes used to treat severe aggression. Side effects may cause sleepiness, dizziness, mood swings, and confusion.
Antipsychotics are drugs used to treat paranoia, hallucinations, agitation, and aggression. Side effects of using these drugs can be serious, including increased risk of death in some older people with dementia. They should only be given to people with Alzheimer’s disease when the doctor agrees that the symptoms are severe.
The Future of Alzheimer's Disease Treatments
Alzheimer’s disease research has developed to a point where scientists can look beyond treating symptoms to think about addressing underlying disease processes. In ongoing clinical trials, scientists are developing and testing several possible interventions, including immunization therapy, drug therapies, cognitive training, physical activity, and treatments for cardiovascular disease and diabetes.