Potenciais interações medicamentosas e fatores associados em adultos residentes em Manaus: Estudo de caso-controle de base populacional, 2019

Abstract

Introduction: drug interactions affect the population and are an important cause of adverse drug events. Evaluations of drug interactions in the population context are scarce. Objective: to evaluate the frequency and factors associated with drug interactions in adults living in Manaus. Methods: this is a case-control study nested in a population-based survey conducted in Manaus in 2019. The sample consisted of three stages; home interviews were carried out through a validated questionnaire that contained identification, sociodemographic, health conditions and medication use questions. Drug interactions were identified and classified according to the Micromedex® software into contraindicated, severe, moderate and minor, with documentation classification as excellent, good and fair. The odds ratio (OR) and the 95% confidence interval (95% CI) of the factors associated with the interaction were calculated by multivariate logistic regression. Results: 2,321 adults were interviewed, 752 participants were using two or more medications and were included. The prevalence of potential drug interactions was 30.7% (95% CI: 27.4; 34.0%). 366 drug interactions were identified, mainly one interaction per person (63.3%), of greater severity (58.2%) and with regular documentation (63.9%); two people used associations of contraindicated drugs. Individuals aged 45-59 years (OR 1.96, 95% CI 1.07-3.59), who used 3 to 4 drugs (OR 2.53, 95% CI 1.76-3.62) and 5 or more drugs (OR 6.27, 95% CI 3.60-10.91) were more likely to have potential drug interactions. Conclusion: more than three out of 10 adults living in Manaus who were treated with two or more drugs in the fortnight showed potential drug interaction, mainly classified as severe. Advanced age and polypharmacy increase the risk of drug interaction.