Cancer patients are at high risk for potential drug interactions

Potential drug interactions from prescribed medications are common among cancer patients and may cause unnecessary harm, according to a study in the April 18 Journal of the National Cancer Institute.
Cancer patients often take several medications at the same time, not only for treating their cancer but also for side effects and other secondary illnesses. Because of this, they can be at high risk for adverse drug interactions and duplicate medications. Consequences of these interactions can range from inactivation of cancer-fighting medications to severely injuring or killing the patient.
Rachel Riechelmann, M.D., of the Princess Margaret Hospital in Toronto, and colleagues gave 405 cancer patients a questionnaire about the medications they had taken in the last four weeks. Their responses were analyzed using a drug interaction software program that could identify potential interactions and rank them by severity.
Nearly a third of patients were exposed to at least one potential drug interaction. The researchers identified 276 drug combinations with the potential to interact. About nine percent of the interactions considered of major severity—risk of death—and 77 percent of moderate severity—risk of serious health problems. About eight percent of the patients received duplicate medications.