The most frequent adverse reactions to Efudex (fluorouracil) occur locally and are often related to an extension of the pharmacological activity of the drug. These include burning, crusting, allergic contact dermatitis, erosions, erythema, hyperpigmentation, irritation, pain, photosensitivity, pruritus, scarring, rash, soreness and ulceration. Ulcerations, other local reactions, cases of miscarriage and a birth defect (ventricular septal defect) have been reported when Efudex (fluorouracil) was applied to mucous membrane areas. Leukocytosis is the most frequent hematological side effect.
Although a causal relationship is remote, other adverse reactions which have been reported infrequently are:
Central Nervous System: Emotional upset, insomnia, irritability
Gastrointestinal: Medicinal taste, stomatitis.
Hematological: Eosinophilia, thrombocytopenia, toxic granulation.
Integumentary: Alopecia, blistering, bullous pemphigoid, discomfort, ichthyosis, scaling, suppuration, swelling, telangiectasia, tenderness, urticaria, skin rash.
Special Senses: Conjunctival reaction, corneal reaction, lacrimation, nasal irritation.
Miscellaneous: Herpes simplex.