Good afternoon. Welcome to Demystifying Alzheimer’s. I’m your hostess Mary Yamin-Garone.
Today’s topic is “Treating Alzheimer’s Symptonms.”
Medications can’t stop or cure Alzheimer’s but there are drugs that can treat certain symptoms. The U.S. Food and Drug Administration (FDA) has approved five prescription medications that target memory loss and other cognitive symptoms of Alzheimer’s and dementia. Other FDA-approved medications treat psychological symptoms, like depression, and behavioral problems, like anger and aggression, in individuals with AD. While none of these drugs will stop or reverse the progression of the disease, they may ease symptoms and provide comfort.
Drugs that Treat Cognitive Symptoms
Cholinesterase inhibitors block the activity of an enzyme in the brain called cholinesterase, which breaks apart the neurotransmitter acetylcholine, a chemical messenger involved in memory, learning and judgment. These inhibitors reduce the action of cholinesterase, which makes more acetylcholine available to the brain’s nerve cells.
Experts believe these medications are only moderately successful in treating the cognitive symptoms of Alzheimer’s. Generally, they delay the worsening of symptoms for six to twelve months in approximately one-half of those who take them. Some individuals see their symptoms improve dramatically but as many as one-half see no noticeable improvement.
The four cholinesterase inhibitors approved to treat different stages of AD differ slightly.
- Donepezil: Originally patented as the brand name Aricept, it is more widely available now as just generic donepezil. It’s the most frequently prescribed cholinesterase inhibitor, accounting for roughly 70 percent of all prescriptions written. It’s approved to treat mild, moderate and severe Alzheimer’s.
- Rivastigmine: Originally patented as Exelon, it’s also available as other brands as well as generic rivastigmine. It prevents the breakdown of both acetylcholine and a similar chemical, butyrylcholine in the brain. It’s approved to treat mild to moderate AD.
- Galantamine: Originally patented as Reminyl, it’s now available as generic galantamine and the brands Reminyl XL, Acumor XL, Galsya XL and Gatalin XL. It prevents the breakdown of acetylcholine and stimulates nicotine receptors in the brain. It’s approved to treat mild to moderate Alzheimer’s.
- Tacrine: (Cognex). The first cholinesterase, approved in 1993, is rarely prescribed today because of its side effects, which include possible liver damage.
How They Work
A brain of someone with Alzheimer’s has lower levels of acetylcholine. Acetylcholine helps send messages between certain nerve cells. In AD, there also is a loss of the nerve cells that use acetylcholine. Falling acetylcholine levels and progressive loss of these nerve cells are linked to worsening symptoms.
Donepezil, rivastigmine and galantamine all stop acetylcholinesterase from breaking down acetylcholine in the brain. As a result, an increased concentration of acetylcholine leads to increased communication between nerve cells. This may temporarily alleviate or stabilize some symptoms.
According to the American Academy of Family Physicians, none of these drugs has proven more clinically effective than another. There also is no evidence that combining two or three of them would improve their results. In fact, combining the drugs appears to cause more side effects.
Some individuals have shown improvement taking doses higher than those typically recommended for each drug. Higher-than-recommended doses also are likely to cause side effects. Common side effects include nausea, vomiting, loss of appetite and increased frequency of bowel movements.
The chemical makeup of each cholinesterase inhibitor varies slightly. One may work better for your loved one than another. Check with your physician if they start to experience any side effects to see if a similar medication will work better for your loved one. Many side effects can be reduced or avoided altogether by taking the drug in different doses or at different times of the day.
Namenda (Memantine) was widely used in Europe for more than 20 years before it was approved to treat moderate and severe Alzheimer’s in the United States in 2003. I was actually able to get this drug for my mother from a London pharmacy well before it was approved here. The action of memantine differs from that of donepezil, rivastigmine and galantamine. Glutamate is another chemical that helps to send messages between nerve cells. It’s released in excessive amounts when brain cells are damaged by Alzheimer’s. Namenda protects brain cells regulating the activity of glutamate, another messenger chemical involved in learning and memory. It is thought to be just as effective as cholonesterase inhibitors in temporarily delaying the worsening of symptoms in some individuals.
According to the National Institute on Aging, because Namenda works differently from other inhibitors in the brain, it may be prescribed in combination with another of those drugs. Some doctors report that individuals who are given Aricept with Namenda do better than those just taking Aricept.
Are These Drugs Effective for All Alzheimer’s Sufferers?
Between 40 and 70 percent of Alzheimer’s sufferers benefit from taking a cholinesterase inhibitor. They can experience reduced anxiety and hygiene, improvements in motivation, memory and concentration and improved ability to perform activities of daily living, including person hygiene, dressing and shopping. It’s unclear if the inhibitors also result in behavioral changes, like agitation or aggression. Trials in this area have yielded mixed results.
Memantine can slow down the progression of symptoms, including disorientation and difficulties carrying out activities of daily living. Some evidence shows it also may help with delusions, aggression and agitation.
That’s all for today. Thanks for listening. I hope this information was helpful.
Join me next time for more about treating Alzheimer’s symptoms.