Drug-drug interactions in oncology: from mechanisms to patient perception

Drug-drug interactions in oncology represent a highly problematic issue to resolve. The events that give rise to clinically significant drug-drug interactions are inherently driven by cancer patients that are often being medicated by more than one drug. Polypharmacy in oncology can result in alterations of chemotherapeutic pharmacokinetic profiles via multiple mechanisms affecting the pharmacodynamics of drugs that are closely related to their pharmacokinetic profiles. In their review article,Mani and colleagues critically analyze the mechanisms by which drug-drug interactions in oncology alter pharmacokinetics and also explore the emerging field of transcriptional control of enzyme/transporter action and its impact on altered drug clearance. Adding another layer of complexity to drug-drug interactions in oncology is the patient’s perception of the definition of a “drug”. Cancer patients undergoing treatment with chemotherapeutics who also consume over-the-counter medications, herbal remedies or supplements without informing their physician run the risk of unknowingly exposing themselves to potentially dangerous drug-drug interactions. In her Editorial article, Professor Marie Hanigan highlights the dangers of patients taking treatment advice from unreliable sources or misinterpretation of the scientific literature and calls for a more in-depth inquiry by the physician into the consumption of non-prescription medicines and other supplements by cancer patients. Professor Hanigan describes the lack of knowledge and confusion among cancer patients regarding the dangers of drug-drug interactions and addresses the challenges facing this large and complex field.