[Show abstract][Hide abstract] ABSTRACT: Forty-one observations concerning persons aged over sixty-five hospitalized for adverse drug reactions in the Emergency Service of Clermont-Ferrand University Hospital were collected and analysed by the Adverse Drug Reaction Monitoring Centre. The symptoms were predominantly haemorrhage, particularly digestive, connected with the use of oral anticoagulants, salicylates and anti-inflammatories. The follow-up of the thirty-one most severe cases (hospitalization over 48 h and/or initial resuscitation) was undertaken in hospital and other care centres. In seventeen cases, complications occurred linked to the hospitalization (especially infections and neuropsychic complications) or to the adverse reaction itself through the measures taken to correct it (particularly cardiovascular complications). The hospitalization revealed hitherto undetected conditions in twelve patients, thereby allowing the prognosis to be improved. This positive side hardly outweighs the detrimental effects of adverse drug reactions in elderly subjects (six deaths and four irreversible incapacitations). Thus vital and social prognosis of elderly appears greatly damaged by adverse drug reactions.