Three common medicines classified as carcinogenic by WHO cancer agency
The WHO's cancer agency, IARC, has classified three common medications—hydrochlorothiazide, voriconazole, and tacrolimus—as Group 1 carcinogens. Health experts emphasize that this is a hazard identification and patients should not stop their medication without medical consultation.
Why it matters
This classification affects millions of patients worldwide who rely on these essential medicines for hypertension, infections, and organ transplants.
Three widely-prescribed medicines used to treat high blood pressure, fungal infections, and organ transplant rejection have been classified as “carcinogenic to humans” (Group 1) by the International Agency for Research on Cancer (IARC), the World Health Organisation’s (WHO) cancer research agency. Experts stressed that the classification is a hazard identification and should not prompt patients to discontinue treatment without consulting their doctors.
The three medicines — hydrochlorothiazide (hypertension), voriconazole (fungal infections), and tacrolimus (an immunosuppressant preventing transplant rejection) — are on the WHO Model List of Essential Medicines, prescribed to millions worldwide.
The assessment, published as Volume 137 of the IARC Monographs, expands on conclusions first released in The Lancet Oncology in November 2024. The 22-member panel included Indian scientist G.B. Jena.
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