The EMA’s Pharmacovigilance Risk Assessment Committee is considering recommending more rigorous patient screening before starting treatment with a common family of anti-cancer and topical skin cream drugs.

Fluorouracil, known under the brand name Adrucil, and similar drugs can be delivered in an injection to treat several forms of cancer and as a topical cream to treat skin conditions. The drug works by causing the death of abnormal skin cells. The topical drug is used to treat scaly overgrowths of skin but may also be used for treatment of superficial basal cell carcinoma.

The advisory committee is worried that the drugs may be building up in the bodies of patients who lack a key enzyme, potentially leading to lower white blood cells, neurotoxicity, severe diarrhea and inflammation of the throat.