Incidence of cancer in patients taking valsartan or amlodipine for ≥1 year

Abstract

Introduction: In July 2018, five generic valsartan products suspected to contain nitrosodimethylamine were recalled. Subsequently, nitrosamines have been found in other drugs produced by chemical synthesis. As valsartan is widely used for hypertension, heart failure and nephropathy, we investigated whether valsartan increases cancer risk relative to amlodipine, a commonly used antihypertensive drug. Methods: Patients who took valsartan or amlodipine for at least 1 year between 1 January 2003 and 30 June 2009 were identified using the Clinical Data Analysis and Reporting System of the Hong Kong Hospital Authority. Patients with previously diagnosed cancers were excluded. Patients were followed until cancer diagnosis, death, loss to follow-up or 30 June 2019, whichever occurred first. Results were analysed using R version 3.6.1. The incidence and 95% confidence interval (CI) of cancer were estimated using Poisson regression. Results: Among 5639 valsartan users and 4386 amlodipine users, 1001 and 855, respectively, had cancer diagnosed during a median follow-up period of 10.97 and 12.12 years. The incidences of cancer are 161.82 (95% CI=138.89-188.54) per 10 000 person-years and 160.84 (95% CI=137.98-187.49) per 10 000 person-years, respectively. Conclusion: Valsartan does not appear to increase cancer incidence when compared with amlodipine.