Objective:

Drug-drug interactions may modify the therapeutic effect or the safety profile of the medicines used in pediatric populations. Although interest on potential drug interactions in these age groups has increased, information on clinically relevant drug-drug interactions is still scarce. The aim of this study was to explore the prevalence and characteristics of potential and clinically relevant drug-drug interactions among pediatric patients hospitalized in two pediatric hospitals of Mexico City.

Method:

A cross-sectional study was conducted on patient records in critical, oncological, burns and other non-critical services by a pediatric resident physician at both hospitals. Micromedex® was used as a source of potential drug-drug interactions data. Subsequently, each interaction’s prevalence, severity and evidence level were estimated. Additionally, drug-drug interaction causality with regard to diverse clinical outcomes of hospitalized patients was determined through the Drug Interaction Probability Scale. The clinical consequences of each interaction were classified by severity.

Results:

The observed prevalence of one or more potential drug-drug interactions in hospitalized patients was 61.3% (52.2-70.4%), whilst the prevalence of real drug-drug interactions was 3.6% (0.1-7.1%). Of potential drug-drug interactions, 60.5% were considered major and only 5.1% contraindicated. These were generally more common in intensive care and burn units. The main pharmacological agents involved in potential drug-drug interactions were opioids analgesics and anti-infective and neurologic agents. Four clinically relevant drug-drug interactions required a regimen change and another prompted an extension of the patient’s hospital stay.

Conclusions:

Potential drug-drug interactions were common in the pediatric patients studied, whereas the frequency of real drug-drug interactions was low. However, some drug-drug interactions required medical actions in addition to routine monitoring. More information is needed on real drug-drug interactions as those related to failed efficacy might be underestimated.