Anti-Dementia Drugs and Co-Medication Among Patients with Alzheimer’s Disease

Abstract

There is a substantial risk of drug-interactions, adverse events, and inappropriate drug use (IDU) among frail Alzheimer's disease (AD) patients; however, there are few studies about co-medication and IDU in clinical settings. To investigate anti-dementia drugs, associated characteristics of cholinesterase inhibitors (ChEIs) and NMDA antagonists, co-medication, and IDU in a large population of outpatients with mild AD. In this cross-sectional analysis of medication characteristics, we analyzed data from the Swedish Dementia Quality Registry (SveDem) on 5,907 newly diagnosed AD patients who were registered in memory clinics. SveDem is a national quality registry in Sweden, which was established in 2007 to evaluate and improve dementia healthcare. Comparisons were performed concerning co-medications, use of ≥3 psychotropic drugs (IDU) and polypharmacy (≥5 drugs) based on anti-dementia treatment (ChEIs or NMDA antagonists). Information on baseline characteristics such as age, sex, living conditions, cognitive evaluation based on the Mini-Mental State Examination (MMSE) score, and diagnostic work-up was also evaluated. The majority of the AD patients were in the mild stage of the disease. Overall, 4,342 (75.4 %) patients received any ChEI, 438 (7.6 %) used an NMDA antagonist and 74 (1.3 %) patients were treated with both. However, 907 (15.7 %) patients were not treated with any anti-dementia drug. While polypharmacy was seen in 33.5 % of patients, only 2.6 % concurrently used ≥3 psychotropic medications. Patients on ChEIs were significantly younger, had a higher MMSE score and were treated with a smaller number of medications (a proxy for overall co-morbidity). Co-medication with antipsychotics [3.3 vs. 7.6 %; adjusted odds ratio (OR) 0.55 (95 % CI 0.38-0.79)] and anxiolytics [5.8 vs. 10.9 %; adjusted OR 0.62 (95 % CI 0.46-0.84)] was significantly lower in the ChEI+ group than in those with no anti-dementia treatment. Patients taking ChEIs were treated with less antipsychotics and anxiolytics than those not taking ChEIs. More research is warranted to elucidate whether use of ChEIs in clinical practice can reduce the need for psychotropic drugs in AD patients.