Adverse Reactions of Monobenzone

Application

The topical application of monobenzone in animals increases the excretion of melanin from melanocytes. The same action is thought to be responsible for the depigmenting effect of the drug in humans. Monobenzone may cause destruction of melanocytes and permanent depigmentation.

The histology of the skin after depigmentation with topical monobenzone is the same as that seen in vitiligo; the epidermis is normal except for the absence of identifiable melanocytes. Therefore, monobenzone is used as a topical medicine to permanently depigment normal skin surrounding vitiliginous lesions only in patients with disseminated (greater than 50 percent of body surface area) idiopathic vitiligo. Monobenzone is also being considered for the treatment of melanoma.

Adverse Reactions

Clinical Trials Experience

There is limited information regarding Clinical Trial Experience of Monobenzone in the drug label.

Postmarketing Experience

Mild, transient skin irritation and sensitization, including erythematous and eczematous reactions have occurred following topical application of Benoquin Cream 20%. Although those reactions are usually transient, treatment with Benoquin Cream 20% should be discontinued if irritation, a burning sensation, or dermatitis occur. Areas of normal skin distant to the site of Benoquin Cream 20% application frequently have become depigmented, and irregular, excessive, unsightly, and frequently permanent depigmentation has occurred.