Many kinase inhibitors, chemotherapeutic agents, antiemetics, antibiotics, and antifungal agents can prolong QT intervals, placing the patient as risk for the life-threatening ventricular arrhythmia Torsade de pointes (Tdp). In addition, common electrolyte imbalances experienced by many patients with cancer compound the risk. Because numerous medications used in oncology and common electrolyte imbalances in patients with cancer increase the risk for Tdp, oncology nurses must be informed about this life-threatening arrhythmia.