Prevalence of drug-drug interactions in pediatrics with cardiac disorders receiving off label drugs- a cross-sectional study

Background: Evidence based medical interventions have improved outcomes of cardiovascular diseases, however, pediatric therapy is still based on clinical experience and extrapolation of adult data. Lack of evidence-based therapy increases the exposure of children to off-label (OL) drugs and clinically significant drug-drug interactions (CSDDIs) ultimately leading to adverse drug reactions. This study evaluated the prevalence of CSDDIs, OL drug use and the associated predictors. Methodology: A cross-sectional study was designed to assess prevalence of CSDDIs and OL prescriptions in 250 patients admitted to pediatric cardiology ward of Hayatabad Medical Complex, Pakistan. DDIs of major severity were categorized as CSDDI. Association of various predictors including OL drug use with CSDDIs was evaluated using logistic regression. Result: Of the total 250 pediatric patients, 28.6% patients were exposed to at least one clinically significant DDI, while 228 (91.20%) patients received at least one OL prescription. Furosemide was the most frequently prescribed drug involved in CSDDIs, while it was also one of the highly prescribed OL drug. Multivariate analysis revealed that, adolescent age group (OR 12.795; CI 3.077-53.198) and patients prescribed > 5 drugs (OR 3.544; CI 1.906-6.589) were significantly 12.7 and 3.5 times more likely to experience CSDDIs in reference to their corresponding categories. Conclusion: A high prevalence of CSDDIs and OL prescriptions was observed. OL drug presence was also observed to be a significant predictor associated with an increased risk of CSDDIs. Thus, to improve pediatric pharmacotherapy suitable medical interventions are required to decrease OL drug use and CSDDIs.