IARC Classifies Three Medicines as Carcinogenic

Key facts

• The International Agency for Research on Cancer (IARC) and the World Health Organisation (WHO) have classified hydrochlorothiazide, voriconazole, and tacrolimus as Group 1 carcinogens.
• Hydrochlorothiazide, a thiazide diuretic used for hypertension, was upgraded from Group 2B based on evidence of malignant liver tumours in male mice and adrenal gland pheochromocytomas in female rats.
• Voriconazole, a broad-spectrum antifungal, is linked to an elevated risk of cutaneous squamous cell carcinoma, especially in immunocompromised patients like transplant recipients.
• Both hydrochlorothiazide and voriconazole are photosensitising drugs that enhance genotoxicity and oxidative stress when combined with UV radiation.
• Tacrolimus, an immunosuppressant used to prevent organ rejection, is also classified as a Group 1 carcinogen and is listed as an essential medicine.