Drug-drug interaction study in an intensive care unit: An assessment of prevalence, nature, and severity of the medications involved

Abstract

Background: Intensive care unit (ICU) patients are at an increased risk of drug-drug interactions (DDIs) due to polypharmacy and pharmacokinetic changes in critically ill patients. Adverse drug reactions in hospitals caused by DDIs pose a significant risk to the patient’s health outcome with an additional economic burden on the health -care system. Aims and Objectives: This study was conducted to measure the prevalence and nature of potential DDIs (pDDIs) as primary objective and to know the severity of pDDIs and association of pDDIs with the length of stay in ICU (if any) as a secondary objective. Materials and Methods: This was a 2-month, prospective, observational study that was conducted in an ICU of ESIC Medical College and Hospital, Gulbarga. Drugs.com interaction database was utilized to screen patient’s medication profiles for DDIs and for severity assessment. Results: Of 112 study population, 755 pDDIs were identified, averaging 6.74 interactions per patient. About 6.9% (52/755) were major, 75.9% (573/755) were moderate, and 19.9% (150/755) were minor DDIs. The most frequent drug pairs involved in pDDIs in major, moderate, and minor were rifampin and isoniazid (15.4%), furosemide and pantoprazole (4.01%), and digoxin and spironolactone (8%), respectively. Conclusions: DDIs occur frequently in the ICU. Nature and Severity of medications related to DDIs in an ICU differ from other hospital ICU settings. Based on the prescribing pattern in an ICU, a database at an institutional level can be developed so as to decrease the burden of interactions and overall result in improved patient safety.