DRUG-USE AND ADVERSE DRUG-REACTIONS IN 105 ELDERLY PATIENTS ADMITTED TO A GENERAL MEDICAL WARD

Objective: To examine the influence of admission to hospital on the nu mber of drugs used by the elderly and to study the occurrence of adver se drug reactions (ADRs), their contribution to the need for hospitali zation and the relation to hospital stay. Patients and methods: Drug u se and its sequelae were studied by one observer in 105 patients aged 65 years and older, successively admitted to a general medical ward. N aranjo's algorithm was used to estimate the probability of an ADR. Mul tiple regression analysis was used to measure interrelationships betwe en variables. Results: There was a slight but significant increase in drug use per patient (4.9 prescriptions on admission, 5.3 at discharge ); 120 ADRs occurred, 57 on admission, 63 during stay. Two ADRs were p otentially fatal. Drugs most often involved were diuretics, ADRs occur ring mainly on admission. During stay in hospital antimicrobials were mainly responsible. There was a strong correlation of both ADRs on adm ission and ADRs during stay with duration of hospital stay. ADRs did n ot correlate with the number of drugs in use on admission or with the number of diagnoses. A direct correlation between the occurrence of AD Rs and age could not be confirmed, when corrected for possible confoun ding factors. Fourteen of 105 admissions were definitely or probably d rug-induced; diuretics were incriminated 6 times. Conclusions: Drug us e per patient corresponded with that in the literature. Thirty-seven p er cent of patients experienced a definite or probable ADR. The percen tage of drug-induced admissions (14.7%) agrees with the literature, al though the drugs involved (mainly diuretics in our study) were markedl y different. The occurrence of ADRs, both on admission and during stay is correlated with the duration of hospital stay, but not with drugs in use or with the number of diagnoses.