Potentially inappropriate medication use in a city of Southeast Brazil

potentially inappropriate medication use by the diamantina (minas gerais state) population was investigated by analyzing medicine consumption, self-medication, polypharmacy and drug interactions of medicines prescribed among those interviewed. level of knowledge about rational drug use and its relationship to socio-economic variables was also evaluated using a semi-structured questionnaire. this survey was based on stratified sampling of 423 individuals selected randomly. the prevalence of prescription drug consumption was 42.32% (n=179) and cardiovascular drugs were the most prescribed. drug interactions were found in 45.81% (n=82) of prescriptions and 92.68% (n=76) of these interactions were moderate, with co-administration of cardiovascular drugs occurring in more than half of the cases. the inappropriate use of medication, according to beers criteria, occurred in 44.73% of prescriptions to the elderly. the prevalence of self-medication was 63.34% (n=268) while 21.99% (n=91) of individuals administered medications to their children without formal prescriptions, where this practice was associated to analgesic/antipyretic consumption. the population showed a high prevalence of inappropriate use of drugs across all strata of society, representing an issue requiring effective actions to promote rational use of medicines.