ASSESSMENT OF CLINICALLY SIGNIFICANT DRUG–DRUG INTERACTIONS IN PATIENTS UNDERGOING POLYPHARMACY IN OUTPATIENT SETTINGS

Abstract

Polypharmacy is on the rise in the outpatient conditions because of the increase in multimorbidity and because of complex treatment regimes. Although multidrug therapy is usually clinically justified, its use increases the chances of possible drug-drug interactions that can impair the efficacy of treatment or result in adverse events that can be prevented. It is imperative to know the prevalence, pattern and determinants of these interactions to enhance medication safety.

Methods: It was a cross-sectional observational study that was carried out by undertaking outpatient departments at a tertiary care hospital during a period of three months. The inclusion criteria were adult patients who were receiving five or more drugs in one prescription. A structured proforma was used to retrieve prescription data and screen them to identify possible drug-drug interactions through a verified prescript interaction database. The severity and mechanism with which interactions took place were categorized, and their association with demographic and clinical variables analyzed using the necessary statistical tests.

Results: Four hundred two hundred patients were involved and those with old age constituted the greatest proportion. All in all, it was possible to identify 822 potential interactions and 71.2% of the patients engaged in at least one interaction. The largest proportion was moderate interactions then minor and major interactions. The most common classes involved cardiovascular medications, antidiabetic medications, NSAID, CNS-acting medications, and antibiotics. These were found to be strongly and statistically significantly correlated with the occurrence of major interactions with patients having over ten medications showing significantly increased risk.

Conclusion: Possible drug-drug interactions outcomes are very common with outpatient polypharmacy prescription and it is evident with the growth of medication burden. Such dominance of clinically meaningful interactions identifies the necessity of systematic medication evaluation, enhanced decision support systems, cautious prescribing conduct, and combined actions of the pharmacist to enhance medicine safety within ambulatory care.