G. H. Sokol,1 L. S. Loftus,1 G. Wright,2 L. R. Cantilena3; 1Moffitt Cancer Center, Tampa, FL, 2Florida Cancer Specialists, Hudson, FL, 3Uniformed Services University, Bethesda, MD

BACKGROUND: Polypharmacy (PPh) is a problem of increasing magnitude with the rise in drug utilization that has been associated with drug-drug interactions, adverse drug events (ADE), hospitalizations, and potential mortality. Cancer patients receiving radiation therapy (RT) may be particularly vulnerable to PPh and its consequences due to the intensity of cancer treatment and the use of medications to alleviate side effects. The purpose of this study was to evaluate the extent of exposure to multiple pharmacologic agents in cancer patients who are receiving RT.

METHODS: 100 randomly selected patients receiving RT for treatment of cancer in an academic affiliated community-based cancer center were evaluated for medications use by retrospective chart review. Patient data included gender, age, primary tumor site, number of drugs utilized, indication, treatment with chemotherapy, and hormonal therapy, when applicable.
RESULTS: Data from 53 males and 47 females were evaluable. Median age: 74.5 (40-96) years; mean age: 73.1 years. Primary tumor sites included 25 lung, 24 skin, 16 breast, 12 head and neck, 10 prostate, 2 brain, and 11 misc. (rectum, bladder, lymphoma, sarcoma) cancers. 45 patients also received chemotherapy; 14 patients received hormonal therapy. The average number of medications/patient was 11.3 including prescribed, OTC and chemotherapeutic agents. Approximately 50% of medications were given for co-morbidities; 30% of medications for analgesia.
CONCLUSION: The use of multiple pharmacologic agents in the treatment of cancer patients receiving RT is prevalent. The potential for ADE from drug-drug, and drug-radiation interactions is significant. Radiation oncologists must be familiar with patients’ medications to prevent ADE and drug-radiation induced events.