Do Alzheimer’s Disease Medications Really Work?

In this excerpt from an article in the Spring 2007 Memory Bulletin, Dr. Peter V. Rabins, Co-Director of the Division of Geriatric Psychiatry and Neuropsychiatry at The Johns Hopkins School of Medicine shares questions from his patients about Alzheimer’s disease medications.

When it comes to drugs for Alzheimer’s disease there are presently four drugs in the anti-cholinesterase class -- Aricept, Exelon, Razadyne, and Cognex (rarely used today because of it’s potential for significant liver toxicity). Namenda, a NMDA receptor antagoinist, was approved by the FDA in 2003 for middle-to-late-stage Alzheimer’s. While there is no cure for Alzheimer’s, these medications play a definite role in the treatment of Alzheimer’s symptoms.

Do the Alzheimer’s drugs really work? This question has caused a big firestorm within the Alzheimer’s field. About 15% to 30% of the time, it is clear that the drug is helping the Alzheimer’s patients. A caregiver will report to the doctor some noticeable change: For example, the patient remembered the caregiver’s name, they started to tie their shoes again, or they regained the ability to go to the bathroom by themselves. Unfortunately for many people, the benefit isn’t this clear, and they continue to decline. It’s hard to know what to do at that time.

Here are some frequently asked questions about Alzheimer’s disease medications.

Q. How do you determine which patient should be using an Alzheimer’s drug?

A. I will give the patient a cognitive screening test that consists of a series of questions and tasks designed to test an individual’s memory and other aspects of cognitive functioning. A common tool used in memory screenings is the Mini Mental State Exam (MMSE). This simple test is based on a 30-point scale and is divided into sections that address orientation, memory, attention, language, and perception -- all of which are aspects of cognitive functioning that become impaired when a person has Alzheimer’s disease or a related dementia.

Scoring on the exam is as follows:

• A score in the mid to low 20s on the exam may indicate mild impairment

• A score between 10 and 20 suggests there may be moderate impairment

• A score of 9 or lower suggests severe impairment

Q. What patient should be taking the Alzheimer’s drugs?

A. The patient who should be taking cholinesterase inhibitors is one who has probable Alzheimer’s disease and is in the mild to moderate stage of Alzheimer’s. That means he or she has a MMSE score of approximately 10 to 26. This group happens to be the best studied of all Alzheimer’s disease patients and we have the most information on them.

Q. How long do the cholinesterase medications actually help the Alzheimer’s patient?

A. This is very hard to gauge. For six months to a year, a patient can maintain the modest benefits if the Alzheimer’s drug is working. Most people I respect as scientists and clinicians are not persuaded that cholinesterase drugs delay cognitive decline or that they slow the destruction of brain tissue caused by Alzheimer’s. I explain to my patients and their caregivers that a person who responds to the drug will experience an improvement in memory of about six to eight months. By this, I mean that if the Alzheimer’s medication were started in June, it is hoped that the patient’s cognition would revert to how it was the previous November. This would be an average improvement. Moreover, if a person does improve, they could maintain this improvement for six to eight months and sometimes longer.