Assessing the Impact of Antidepressants on Cancer Treatment: A Retrospective Analysis of 14 Antineoplastic Agents.

Background: Rates of depression among patients with cancer have increased, illustrating the importance of mental health care during treatment. This study sought to identify antidepressants with boxed warnings for increased suicidal risk and known to have drug-drug interactions. Methods: This retrospective analysis used the US Department of Defense Cancer Registry, Comprehensive Ambulatory/Professional Encounter Record, and Pharmacy Data Transaction Service databases. Patients with cancer were identified, and data collected included patient diagnoses and dispensed medications. Medications were divided into groups based on the pharmacy database therapeutic codes. Results: This analysis identified 2210 patients with 2104 documented diagnoses, 2113 recorded prescriptions treated with 14 antineoplastic agents. Breast, lung, testicular, endometrial, and ovarian were the most common cancers among the 51 types treated. Of the 2113 patients with recorded prescriptions, 1297 patients (61.4%) received 109 cancer medications, including 96 different antineoplastics; 750 (35.5%) patients were prescribed 17 different types of antidepressants. In addition, 1089 unique prescriptions were filled (8 medications prescribed for ≥ 1000 patients). Patients who took antidepressants had more diagnosed health issues and received more prescription medications. The mean number of prescriptions dispensed in patients prescribed antidepressants vs those not prescribed antidepressants showed a significant difference (P < .05) in all groups, except anticonvulsants (P = .12) and other antipsychotics (P = .09). Although antidepressant treatment increased, there was no significant change in antidepressants prescribed annually (mean [SD] 23% [5%]). Conclusions: The study provides a comprehensive overview of noncancer medication use in the Military Health System during systemic cancer treatment, specifically the use of antidepressants from 2003 to 2022, and highlights potential drug interactions that may affect treatment outcomes. Future research should prioritize the analysis of drug-drug interactions between cancer and noncancer drugs with antidepressants.