Comments on Draft Revision of Medicare Prescription Drug Benefit Model Guidelines, Jan 2006

Published Friday, January 6, 2006 7:00 am

US Pharmacopeia
12601 Twinbrook Parkway
Rockville, MD 20852

Attention: Deborah Perfetto

Dear Ms. Perfetto:

The American Association for Geriatric Psychiatry (AAGP) is pleased to offer comments on the draft revision of Medicare Prescription Drug Benefit Model Guidelines that was published by United States Pharmacopeia on December 9, 2005.

AAGP is a professional membership organization dedicated to promoting the mental health and well-being of older adults and improving the care of those with late-life mental disorders. Our membership consists of more than 2,000 geriatric psychiatrists as well as other health care professionals who focus on the mental health problems faced by senior citizens.

Use of psychotropic medications and other drugs by elderly patients especially frail elderly patients poses complex challenges. The effects of normal aging on pharmacokinetics and pharmacodynamics, coupled with the presence of multiple chronic diseases, and the common need for treatment with multiple prescription drugs, require careful medication management and coordination with other physicians. Geriatric psychiatrists typically treat patients with such a profile. They must choose drug regimens that minimize the risk of adverse events, including disease-drug and drug-drug interactions, and carefully monitor drug treatment responses and tolerability in this vulnerable segment of our patient population.

AAGP would like to address one specific proposal contained in the revised guidelines. The proposal to collapse the pharmacologic classes of anti-dementia drugs into a single category is mistaken both in concept and in its effect on this most frail and vulnerable patient population.

Anti-dementia drugs currently available fall into two distinct classes, cholinesterase inhibitors, including three drugs currently marketed in the United States, and glutamate pathway modifiers, currently including only one drug, memantine.

The following points, singly and together, make it clear that the proposal to collapse these drugs into a single category is misguided and, most importantly, will jeopardize the health and safety of these frail patients.

* The mechanisms of action for cholinesterase inhibitors and glutamate pathway modifiers are entirely different. They work in different parts of the brain and have different biological effects.

* The two classes are approved by the FDA for different stages of dementia. Cholinesterase inhibitors are approved for mild to moderate dementia, while memantine is approved for moderate to severe stages.

* Patients with moderate to severe dementia may safely take both medications and there is evidence that they may benefit from taking both, precisely because they are different drugs with different mechanisms of action.

* Especially important for these patients, the side effects of these two classes are different. For patients who cannot tolerate a cholinesterase inhibitor due to excess sensitivity to the gastrointestinal side effects, it is most important to have memantine available. It is likely that this gastrointestinal sensitivity would exist for a second cholinesterase inhibitor but not with memantine. If memantine is not available for these patients, they are effectively barred from any treatment.

AAGP believes this proposal is clearly contrary to the whole concept of setting up a system that differentiates classes of drugs to allow access to those best suited for individual patients and their conditions. The decision arbitrarily concludes that there is only one class of dementia drugs when in every description of the drugs how they act, the part of the brain affected, the stage of illness to be treated, and the side effects there are clear differences, which have been demonstrated by both clinical and scientific evidence.

AAGP strongly opposes the proposed revisions in the anti-dementia category and we urge USP to reject them. We appreciate the opportunity to offer our comments.


Christine M. deVries
Executive Director