[Inappropriate drug prescription and adverse drug effects in elderly patients]

Aims: Inappropriate drug prescription (IP) has been related to higher hospitalization rates and development of adverse drug effects (ADE). We have studied the inappropriate drug prescriptions given to elderly patients admitted to the hospital and the frequency and severity of the adverse events related with them.

Patients and methods: A prospective study was conducted in a sample of 100 patients over 65 years admitted in an Internal Medicine Department in whom at least one inappropriate drug prescription (Beers and STOPP (B-S) criteria [Screening Tool of Older Person's Prescriptions]) as outpatients or during the first 48 hours after the admission. The relationship of the adverse events with the inappropriate drug prescription was established using the Naranjo algorithm.

Results: A total of 97 patients, mean age 81 years (range 66-101) were included. The total amount of medicines prescribed during the hospital stay was 865, average of 9 (range 3-16). Thirty two percent was being treated with more than 10 drugs. A total of 153 (17.7%) were B-S drugs. There were 26 ADEs, 18 related with B-S drugs. Digoxin and lorazepam were the IP drugs most frequently prescribed and those related with a larger number of ADE. Fifty six percent of the ADEs were considered severe. Institutionalized elderly patients were treated with more drugs, but not more B-S medicaments.

Conclusions: The frequency of ADEs related to IP is very high in the elderly. It is necessary to implement strategies to identify, and use properly these drugs in elderly population.