DEMENTIA MEDICATIONS

IMPORTANT! This information is meant to be used only for general information, in accordance with current medical information and the practice experience of this geriatrician and should never be used alone, outside of the medical advice of one’s personal physician.

The most direct drug treatments for dementia seek to improve the supply of key brain chemicals, or to improve cardiovascular health that will avoid the mini-strokes that can cause vascular dementia.

Anti-cholinesterase Inhibitors

The most focused drug for dementia is Donepezil, or Aricept®. This medicine is one of several “anti-cholinesterase inhibitors.” These drugs increase the production of “choline.” This chemical forms one of the building blocks of “acetylcholine,” a key “neurotransmitter,” the scientific name for a substance that helps brain cells signal each other.

This class of drugs can help keep the nursing home at bay for an extra six to nine months. However, the drugs only help 10 to 30 percent of dementia patients. Unfortunately, it’s impossible to knowwhich 10 to 30 percent. Therefore, it’s common to give these medicines to all patients with declining brain function. While these medications cannot reverse delirium (the sudden confusion of time and events), they may take the edge off angry reactions. Empirically, some patients’ behavior may improve somewhat with these drugs.

Donepezil is by no means a cure-all. While the drug is perhaps the best-studied of the dementia drugs, it remains controversial in many medical circles. The medication is expensive and the benefits are modest. In fact, there is no definitive proof that the drug alters the course or the progression of Alzheimer’s. Further, the FDA has not approved it for use in other kinds of dementia. (However, it is commonly prescribed “off-label” for these conditions.) The side effects may be uncomfortable: insomnia, or sedation, nausea, diarrhea, decreased blood pressure and heart rate. Occasionally, the drug causes behavioral problems. Still, Donepezil is certainly worth trying. If the patient’s function remains stable, it may even be working.

Several similar drugs also affect choline uptake:

Galantamine/Razadyne®Rivastigmine/Exelon® In my practice, I have seen Rivastigmine relieve the behavior symptoms of dementia in several patients Yet these drugs also remain controversial for similar reasons as, and have side effects similar to, Donepezil/Aricept®. If the drug causes side effects like stomach upset or decreased appetite, the medication may be administered in a patch form, in which the drug is absorbed through the skin.Memantine/Namenda® works by affecting how nerves absorb “glutamate,” another chemical that helps brain cells communicate. It’s thought that in Alzheimer’s patients, brain cells take in too much glutamate. This may lead to an “over-excited” state that makes the cells die. Some studies have shown that prescribing Donepezil and Memantine together may be more effective than Donepezil alone. But, again, controversy reigns. Memantine can calm behavior but may leave patients over-sedated. I have had some patients benefit from this medicine. Yet for many, this medicine does not make a difference.

Blood Thinners

One of the major types of dementia is “vascular dementia,” in which little strokes damage small parts of the brain. These little strokes may not show up on a head CAT scan, but rather as small “white matter changes,” or little scars. Patients who have suffered from little strokes like these may exhibit increased confusion, or loss of abilities. These problems may improve slightly, but rarely improve to the level of function before the stroke. Thinning the blood can help avoid the damaging strokes.

Baby aspirin (81 mg) thins the blood. In preventing these problems, baby aspirin is more cost effective than any other medication. The biggest side effect of thinning the blood is that it increases the risk of bleeding: mostly in the stomach, but sometimes elsewhere. Injuries, especially falls, may be a concern when a patient is taking baby aspirin. This risk of stomach bleeding can be decreased with a “proton pump inhibitor” such as omperazol/Prilosec, the most common and inexpensive.

To prevent strokes, baby aspirin generally should not be used with clopidogrel/Plavix, a drug that prevents blood clots. (However, if a patient has a stent keeping a heart artery open, both aspirin and Plavix may be prescribed.)

Make sure to discuss these issues with your doctor. Studies have not shown that baby aspirin and Plavix prevent recurring stroke better than Plavix alone. However, it will increase the bleeding risk. Yet, when a patient who is already taking baby aspirin has a stroke, the evidence indicates switching to Plavix or Aggrenox®, rather than just increasing the dose of aspirin. Recent studies have also suggested that patients with irregular heart rhythms (“atrial fibrillation”), Plavix may be a good second choice to reduce stroke risk (of course Coumadin is the first choice). Unfortunately, the major side effect is bleeding, something that cannot be reversed quickly.

Aggrenox®, a combination of aspirin and dipyridamole/Persantine®, may be used if a patient has a stroke while taking aspirin. The stronger blood thinning effect may decrease the risk of another stroke, but may increase headache risk. Warfarin/Coumadin® reduces the amount of vitamin K, needed for the formation of blood clots. This will thin the blood. It may be used if there’s a risk of clots “upstream” from the brain that might break off and cause major damage. This drug may also be useful for a patient whose carotid artery has narrowed, if there’s a clot on a heart valve, or if the heart beats irregularly (“atrial fibrillation”). To follow the response to this medication, patients should have regular blood tests for prothrombin time (how long it takes blood to clot).

Risks and benefits need to be weighed carefully with this drug; thinning someone’s blood comes with very real downsides. If a patient remains quite functional—walking, communicating, eating well—then the goal is to preserve that function and reduce the risk of stroke. Coumadin®, Plavix® or Aggrenox® may be the answer in that case.

However, if a patient has already become confused, and falls frequently, then the risk of increased bleeding is probably more of a danger than the risk of stroke. In that case, it might be best not to use these drugs.