Evaluation of drug interactions in patients treated with antidepressants at a tertiary care cancer center

Objective We evaluated potential drug interactions in patients treated with antidepressants at a tertiary care cancer center to determine if it affects resource utilization. Methods We identified a cohort of patients with continuous care at the study institution by tagging patients who received at least three prescriptions for antidepressants within a continuous 6-month period. Data collected included demographics, cancer type and comorbidities, resource utilization (hospital and emergency room visits), and potential major drug interactions. Descriptive statistics and logistic regression were utilized in the analysis. Results The study population, which included 297 patients, was 70% female and 71% Caucasian; the mean age was 53 years (SD, 12 years), with a mean follow-up period (duration of therapy) of 403 days. Overall, 145 (49%) of the patients had a drug combination that could result in a potential major drug interaction with antidepressants. There were 118 (40%) patients with a potential major drug interaction that could lead to serotonin syndrome symptoms and 59 (20%) patients with a potential major drug interaction with anticoagulants. Potential major drug interactions were associated with an increased number of hospital and ER visits (odds ratio [OR], 2.37; 95% confidence interval [CI], 1.39-4.03). This finding was consistent for the two subanalysis groups as well, serotonin syndrome-inducing drugs (OR, 2.28; 95% CI, 1.33-3.92) and anticoagulants (OR, 3.66; 95% CI, 1.85-7.22). Conclusion Potential drug interactions are frequent in patients receiving antidepressants in a tertiary care cancer center and are associated with an increase in resource utilization.