Cholinesterase inhibitors stabilize Alzheimer disease

During the last decade, a systematic effort to develop a pharmacological tr eatment for Alzheimer disease (AD) has resulted into three drugs being regi stered for the first time in USA and Europe for this specific indication. A ll three are cholinesterase inhibitors (ChEI). The major therapeutic effect of ChEI on AD patients is to maintain cognitive function at a constant lev el during a 6 months to one year period of treatment as compared to placebo . Additional drug effects might be slowing cognitive deterioration and impr oving behavioral and daily living conditions. Com parison of clinical effec ts of 6 ChEI demonstrates a rather similar magnitude of improvement in cogn itive measures. For some drugs, this may represent an upper limit while for other it may still be possible to increase further the benefit. In order t o maximize and prolong positive drug effects it is important to start early and adjust dosage during the treatment. Recent studies show that in many p atients the stabilization effect produced by ChEI can be prolonged for as l ong as a 24 month period. In order to explain the stabilizing effect of ChE I, a mechanism other than AChE inhibition, based on beta-amyloid metabolism , is postulated.