Optimizing chemotherapy: Concomitant medication lists

Identifying sources of variability in the response to cancer chemotherapy requires knowledge of all variables including concomitant medications, which can alter metabolism and pharmacokinetics of chemotherapy. This study investigated the accuracy of concomitant medication lists in the charts of cancer patients. Collated information from a questionnaire, patient interview and patient’s medical chart were used to obtain validated medication lists. Patients took an average of 4.8 prescription drugs, 1.6 non-prescription drugs and 1.6 other remedies within three days prior to chemotherapy. Medical records did not report 24% of prescription drugs, 84% of non-prescription drugs and 83% of other remedies. Electronic medical records were more complete than paper charts, but failed to report more than 75% of non-prescription drugs and other remedies. Potential drug interactions were noted. This study documents the extent and complexity of concomitant drugs taken by patients undergoing chemotherapy and the deficiencies in recording this information in medical charts.