Assessment and Evaluation of Drug-Drug Interactions in an Intensive Care unit of a Tertiary Care Hospital and Clinical Pharmacist's Intervention Strategies

Abstract

Aims: To identify and assess the prevalence of Drug-Drug Interactions (DDIs) in the prescriptions filled at Intensive Care Unit(ICU). To suggest necessary clinical pharmacist interventions and assess the importance of clinical pharmacist in ICUs. Methodology: Prospective interventional study conducted in a tertiary care hospital setting, South India for a period of six months (October 2017- March 2018) after the approval from Independent Review Board (PD007/IRB/NRML/17-18) A total of 120 prescriptions were screened during the study period for the possible DDIs by using Lexicomp software and Drugs.com drug interaction checkers. Identified DDIs were categorized based on their severity in to three types (major, moderate, minor DDIs) and based on their mechanism in to two types (Pharmacokinetic(PK), and Pharmacodynamic (PD) DDIs). Necessary clinical pharmacist interventions were proposed and discussed with the doctors during ward rounds. The acceptance of proposed interventions; outcomes of the study were documented. Different factors like age of the patients, number of medications, length of hospital stay and number of co morbidities were assumed to be the predictors contributing to DDIs .Statistical Analysis was done by using SPSS software 20.0 and Pearson’s test was used to assess the significant correlation between the predictors of DDIs. Results: Out of a total of 120 prescriptions screened, a total of 97 possible DDIs were observed in 65 prescriptions. The incidence of at least one DDI per prescription was 32.5%, two DDIs per prescription were 14.17% and more than two DDIs per prescription were 7.50%.The most prevalent type of DDIs was found to be moderate drug interactions accounting for 51.55% followed by major (32.99%) and minor (15.46%)DDIs. The high risk category of drugs involved in the DDIs was found to be Antibiotics (28.26%). Pharmacodynamic interactions (71.13%) with synergistic action (29.89%) were found to be most prevalent. Number of medications, length of stay and number of diagnosis were found to be significantly related to the risk of DDIs (P value 0.04, 0.05, 0.04 respectively).The level of acceptance of proposed interventions was 50%. The outcomes of the proposed interventions showed that a total of 28 possible potential DDIs had been prevented. Conclusion: Most of the drug interactions were predicable and preventable. The level of acceptance of interventions and the positive outcomes of this study supports the need for a clinical pharmacist in Indian hospital setting to optimize the patient care and improve the patient safety.