Adverse drug reactions in elderly patients with cognitive disorders: A systematic review

Elderly subjects with cognitive disorders are at particularly high risk of adverse drug reactions (ADRs). The objectives of our systematic review were to describe the prevalence of ADRs in elderly patients with cognitive disorders, the different types of ADRs and the medications suspected of involvement; to describe whether the ADRs were preventable or not, and to identify risk factors for occurrence of ADRs in this population. A bibliographic search was performed in the following databases: PubMed, Embase, Google Scholar, Opengrey and Scopus. The search included all publications up to and including 4th February 2015, with no specific start date specified. Studies concerning ADRs in elderly patients with cognitive disorders or dementia were included. Two senior authors identified eligible studies and extracted data independently. In total, 113 studies were identified by the bibliographic search, of which six full-text articles were retained and analyzed. Prevalence of ADRs ranged from 4.8 to 37%. The main ADRs reported were neurological and psychological disorders, gastro-intestinal disorders, dermatological and allergic disorders, falls, renal and urinary disorders, cardiovascular disorders, metabolic disorders and electrolyte imbalance, and hemorrhagic events. The medications most commonly suspected of involvement in the ADRs were drugs affecting the nervous system, cardiovascular drugs, anticoagulants, and painkillers. Medical prescriptions should take into account the presence of Alzheimer's disease and related syndromes. Compliance should systematically be evaluated, and cognitive disorders need to be better recognized. Therapeutic education of patients and/or their caregiver is key to management of elderly patients with cognitive disorders.