Potential drug-drug interactions among hospitalized cardiac patients

Ajay D. Shanbhag, Hema N. G., K. S. Sadananda


Background: Drug-drug interactions (DDIs) are a major cause for concern in patients with cardiovascular disorders due to multiple co-existing conditions and the wide class of drugs they receive. The objective of our study was to identify potential drug-drug interactions among hospitalized cardiac patients and to identify the risk factors associated with these interactions.

Methods: After obtaining approval from Institutional Ethical Committee, a prospective observational study was carried out among 367 hospitalized cardiac patients in Sri Jayadeva Institute of Cardiovascular Sciences and Research, Mysuru. Cardiac patients prescribed at least 2 drugs and having hospital stay of more than 24 hour duration were enrolled into the study. The prescriptions were analysed for potential DDIs using MEDSCAPE multidrug interaction checker tool. Descriptive statistics, Student ‘t’ test, ANOVA and Pearson correlation coefficient were used to analyse the results.

Results: The incidence of potential DDIs was 98% with 360 prescriptions having at least one potential DDI. A total of 38 potentially interacting drug pairs were identified among which majority were of significant grade while only 3 were serious. Majority of interactions were pharmacodynamic (76.3%) in nature. Aspirin/clopidogrel (71.1%) and pantoprazole/clopidogrel (69.8%) were the most common interacting pairs. Drugs most commonly involved were aspirin, clopidogrel, heparin, pantoprazole and ramipril. Age, female gender, polypharmacy, prolonged hospital stay, stay in ICU and diabetes mellitus were the risk factors found associated with the potential DDIs.

Conclusions: Proper therapeutic planning, routine monitoring of cardiac in-patients and usage of online DDI database will avoid potentially hazardous consequences in cardiac in-patients.


DDIs, MEDSCAPE, Cardiac in-patients

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