The burden of drug interactions in oncology: Prevalence, risk factors and severity in a tertiary care hospital

BackgroundPatients ongoing cytotoxic chemotherapy concomitantly receive drugs for prevention of adverse effects as well as treatment for comorbidity. Exposure to such large number of drugs increases the chances of drug-drug interactions. This study was planned to determine the potential drug interactions and risk factors associated with them, in cancer patients of a tertiary care teaching hospital.MethodologyProspective, observational study conducted in the adult and pediatric oncology units. Data of medications received by each patient entered in UpToDate software to get the information about potential drug interactions (pDDI). Any observed outcome due to the drug interaction was noted down along with its management. Welch's independent samples t-test was conducted to identify quantitative factors that had a significant impact on observed Drug-Drug Interactions (oDDI). Pearson's correlation coefficient was calculated for all quantitative variables.ResultsOut of 110 patients, pDDI were found in 93.6% of them and actually occurred in 49.1% of these patients. Most of the pDDI were between the co-administered drugs (67.1%) in whom supportive medications were given or patient monitored. Significant association was found between the number of drug-drug interactions (DDIs) and age of the patient (p = 0.020), total number of drugs used (p < 0.001), number of drugs for comorbidities (p = 0.024), and number of co-administered medications (p < 0.001).ConclusionHigh prevalence of drug interactions among cancer patients indicates the need to develop protocols for monitoring and effective communication between healthcare providers for safe and effective care.