QTc Interval-Prolonging Medications Among Patients With Lung Cancer: Implications for Clinical Trial Eligibility and Clinical Care

Abstract

BackgroundConcomitant medication use, including agents that prolong the corrected QT (QTc) interval, can result in the exclusion of patients with cancer from clinical trials. To estimate the potential effects on accrual, we determined the prevalence of QTc-prolonging medication prescriptions in a national patient cohort. Patients and MethodsWe identified adult patients in the Veterans Affairs system with a diagnosis of lung cancer from 2003 to 2016. The use of QTc interval-prolonging medications and risk category were obtained from CredibleMeds. We calculated the prevalence of prescriptions for QTc-prolonging medications with a known or possible risk of torsade de pointes in the 3 months up to and including the date of cancer diagnosis. The rates across patient groups were compared using χ2 test. ResultsA total of 280,068 patients were included in the present study. The mean age was 70 years, 98% were male, and 72% were white. Overall, 28.4% had been prescribed a QTc-prolonging medication, and 7.3% had been prescribed ≥2 in the 3 months before the cancer diagnosis. The most commonly prescribed QTc-prolonging medications were antimicrobial agents (14.0%), psychiatric agents (10.2%), antiemetic agents (2.6%), and cardiac medications (1.7%). Excluding the antimicrobial agents, 18.4% of the patients had been prescribed a QTc-prolonging medication. ConclusionsA substantial proportion of individuals with lung cancer will be prescribed QTc-prolonging medications. These prescriptions can limit patients’ eligibility for clinical trials and complicate the administration of standard cancer therapies. Further research into the actual clinical risks and optimal management of QTc-prolonging medications in cancer populations is warranted.