Regulatory response to contaminated valsartanBMJ 2018; 362 doi: https://doi.org/10.1136/bmj.k3855 (Published 12 September 2018) Cite this as: BMJ 2018;362:k3855
- Rita Banzi, head,
- Vittorio Bertele’, researcher
- Center for Drug Regulatory Policies, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via La Masa 19, 20156 Milan, Italy
- Correspondence to: R Banzi
Despite being limited by its short follow-up, the registry based cohort study by Pottegård and colleagues (doi:10.1136/bmj.k3851) provides reassuring interim evidence about the risk of cancer in patients treated with valsartan products contaminated with a probable human carcinogen (N-nitrosodimethylamine, NDMA).1 This study was planned, conducted, analysed, and published within three months from the notification of this quality issue to regulatory authorities.2 It would not have been possible without linking data from four Danish nationwide registries collecting information on prescriptions, cancer diagnoses, hospital admissions, mortality, and migration. The authors report no increase in overall cancer risk among users of potentially contaminated valsartan products followed up for a median of 4.6 years.
This study alone cannot dispel doubts about the potential risk for patients in the longer term, but it helps inform decision making around this episode. It also illustrates the usefulness of national registries for examining the relations between risk factors and health problems and how research can give a prompt response whenever public …