Patterns, predictors and preventability of adverse drug reactions in the coronary care unit of a tertiary care hospital.

Aim: To determine the frequency of occurrence, risk factors, clinical spectrum and drugs associated with adverse drug reactions (ADRs) occurring in the coronary care unit (CCU) of a tertiary care hospital.

Methods: This was a retrospective cohort study based on evaluation of the medical records of consecutive patients admitted to the CCU between January 2008 and December 2008. Each prescription was monitored for ADRs, and each ADR was assessed for causality, severity, predictability and preventability by two physicians using relevant scales. The chi-square test and independent t test were used to compare the ADR and non-ADR groups. Multiple binary logistic regression was used to identify risk factors for developing ADRs in the CCU.

Results: Of 595 patients, 152 (25.5%) developed ADRs, of which 45% were potentially preventable. Severe ADRs constituted 28.6% of the total ADRs. Patients who developed an ADR had a longer duration of stay in the hospital (2.8 extra days) (p < 0.05). Hypokalemia/hyperkalemia (22%), bleeding (11%) and cardiac arrhythmias (11%) were the commonest ADRs. The highest rates of ADRs were seen with streptokinase (59.4%). The predictors for developing an ADR in the CCU included renal dysfunction [odds ratio (OR) 1.66, 95% confidence interval (CI) 1.007-2.72], arrhythmias (OR 1.74, 95% CI 1.052-2.87) and polypharmacy with more than ten drugs (OR 11.3, 95% CI 1.45-87.44).

Conclusion: A high frequency of ADR occurrence was identified, with many of the ADRs being potentially preventable. Patients with renal dysfunction or cardiac arrhythmias and those receiving polypharmacy were at an increased risk for developing an ADR in the CCU.