Potential Drug Interactions in Terminally-Ill Cancer Patients, a Report from the Middle East

This study aims to evaluate the epidemiology of potential drug interactions in terminally-ill cancer patients receiving exclusively supportive care. In this cross-sectional study, during a 6-month follow-up, we considered the medical record of terminally-ill cancer patients referred to palliative care at the cancer center in Isfahan, Iran. Potential drug-drug interactions (DDIs) were assessed by Lexi-Interact ver.1.1 online software. During the study period, 133 terminally-ill cancer patients were recruited. We detected 1678 DDIs with moderate or major severity levels. Among them, 330, 219, 32, 1075, and 51 interactions were categorized in B, C, D, and X drug interactions categories, respectively. One hundred and twenty-two patients (91.73%) encountered at least one potential drug-drug interaction during the end of life care. Mechanistically, most drug-drug interactions (64.5%) were pharmacodynamics. The most frequent pharmacological class of drugs responsible for DDIs were quetiapine (91 cases), oxycodone (87 cases), and sertraline (55 cases). Interaction between oxycodone and sertraline was found to be in the top 10 detected DDIs (13.7%). Our results showed that potentially moderate or major drug-drug interactions often occur among terminally-ill cancer patients and the clinical significance of DDIs should be considered meticulously in the palliative care cancer setting.