DEAR DOCTOR K:
My mother has been diagnosed with Alzheimer’s disease. Can you tell me about medications that are available to treat this disease? What can and can’t they do?
Alzheimer’s disease is a form of dementia. It often affects short-term memory early on. It then progresses to impair other cognitive functions such as thinking and judgment. As the disease advances, it can affect a person’s mood and behavior. Eventually, most people lose their ability to do normal daily activities.
Currently, no treatment prevents or stops the cognitive decline from Alzheimer’s disease. Medications can improve symptoms only temporarily.
Four drugs are FDA-approved in the U.S. to treat Alzheimer’s: donepezil (Aricept), rivastigmine (Exelon), galantamine (Razadyne) and memantine (Namenda). (I’ve put a table with more details about these medications on my website, AskDoctorK.com.) These drugs make modest improvements in memory and cognitive function in some people with the disease.
The first three of these drugs are in a class called cholinesterase inhibitors. Only about 30 to 50 percent of the people who take them show benefits. Even then, the effects last only an average of six months.
Memantine is an NMDA antagonist. It is most effective for people with moderate to severe Alzheimer’s disease. Again, it usually provides only a modest benefit that might be apparent for six months or less. It’s not clear whether taking memantine with a cholinesterase inhibitor provides more benefit than taking each alone.
Medications can also help with behavior problems, such as agitation or outbursts of anger. Brain damage influences the way people act and react. As comprehension falters, behavior problems can soar. When the environment seems confusing and overwhelming, someone with Alzheimer’s disease may become angry or even violent.
Strategies such as simplifying the environment and establishing a routine can help. But if behavior problems continue, a doctor may prescribe psychiatric medications.
Three classes of drugs may be used to treat emotional and behavioral problems. They are antidepressants, mood stabilizers and antipsychotics. Try not to expect immediate results. Doctors usually begin with a low dose and increase it gradually.
Research is ongoing to find new, effective treatments. The goal of future therapies is to prevent the loss of neurons in the areas of the brain involved in memory and cognition. Only then can scientists slow or stop the worsening of the disease. Researchers are investigating several compounds that intervene in this destructive process.
When I attended medical school, medicine knew what the brain of a person with Alzheimer’s disease looked like under the microscope. But we didn’t know why it looked that way, or what was causing the brain to malfunction.
In the past 30 years, medical research has identified several molecules that clearly are involved in producing the brain damage of the disease. I’m optimistic that targeting these molecules with conventional (pharmaceutical) and unconventional treatments (even types of immunization) will someday prove to be effective. When will that day come? I’d guess within 25 years.