Cholinesterase Inhibitors
Cholinesterase inhibitors represent the only class of medications that are FDA-approved to treat dementia, specifically Alzheimer’s disease. After tacrine came donepezil (Aricept), rivastigmine (Exelon), and galantamine (Reminyl). Although these medications were developed to treat patients with Alzheimer’s disease, the pharmaceutical industry has become aware that the market for mild memory loss is much larger. Aricept has been shown to improve cognition in patients with multiple sclerosis, and is now being tested in people with mild to moderate memory loss. The other newer cholinergic agents may have similar properties. The underlying rationale is that cholinergic nerve cells decay in all of us during the aging process, and cholinesterase inhibitors can reverse this deficit and thereby improve cognitive performance.
Combination Therapies Need to Be Tested
From a theoretical perspective, tackling different pathways that lead to memory loss may be more beneficial than dealing with only one pathway, but a few studies that attempted combination therapies met with poor results. The Alzheimer’s study using vitamin E plus selegiline showed no advantage for the combination over either medication taken alone. Earlier, Ken Davis’s group at Mount Sinai Medical Center in New York tried a medication cocktail to simultaneously correct the cholinergic and adrenergic (norepinephrine) deficits in Alzheimer’s disease, but the combination did not work well in a clinical trial.
But another incidental finding suggests that the search for an optimal combination therapy should not be abandoned. In the tacrine study of patients with Alzheimer’s disease, the medication’s effect was strongest in women taking estrogen, indicating that the combination was better than tacrine alone. In an entirely different field, AIDS treatment underwent a revolution after combinations of protease inhibitors were shown to be much more effective than single medication regimens. In the future, I expect that a number of combinations will be studied from the potpourri of therapies for memory loss: ginkgo biloba, donepezil, vitamin E, estrogen, and COX-II inhibitors, to name a few. At this stage, it is impossible to predict which combination of two or three or four medications will prove superior to treatment with individual medications.
Note that the Memory Program relies on a multilayered strategy that includes the judicious use of carefully selected combinations of medications.
Taken From: The Memory Program How to Prevent Memory Loss
and Enhance Memory Power
