Potentially inappropriate medication prescribed to elderly outpatients at a general medicine unit
To establish the prevalence of potentially inappropriate medications prescribed for elderly patients, to identify the most commonly involved drugs, and to investigate whether age, sex and number of medications were related with the prescription of these drugs.
Prescriptions for 1,800 elderly patients (≥ 60 years) were gathered from a database. These prescriptions were written by general physicians at a tertiary level university hospital in the city of Sao Paulo, Brazil, from February to May 2008. Only one prescription per patient was considered. The prescriptions were classified according to sex and age (60-69, 70-79 and ≥ 80). The Beers criteria (2003 version) were used to evaluate potentially inappropriate medications.
Most of the sample comprised women (66.6%) with a mean age of 71.3 years. The mean prevalence of potentially inappropriate medication prescriptions was 37.6%. The 60-69 age group presented the highest prevalence (49.9%). The most frequently prescribed potentially inappropriate medications to women were carisoprodol, amitriptyline, and fluoxetine; amitriptyline, carisoprodol, fluoxetine and clonidine were prescribed more often to men. The female sex (p<0.001; OR=2.0) and number of medications prescribed (p<0.001) were associated with prescription of potentially inappropriate medications. The chance of having a prescription of these drugs was lower among patients aged over 80 years (OR=0.7). The mean number of prescribed medications for both sexes and all age groups was 7.1. The mean number of medications per patient was higher among females (p<0.001); this result was not age-dependent (p=0.285).
The prevalence of potentially inappropriate medications was similar to previously reported values in the literature and was correlated with the female sex. The chance of having a potentially inappropriate medication prescription was lower among patients aged over 80 years. The chance of having a potentially inappropriate medications prescription increased proportionally with the number of medications prescribed (≥ 5).