Butenafine
Butenafine, sold under the brand names Lotrimin Ultra, Mentax, and Butop, is a synthetic benzylamine derived antifungal drug.
It is structurally related to the allylamine antifungals terbinafine & naftifine.
Medical uses
Butenafine is indicated for the topical treatment of tinea versicolor due to Malassezia furfur, as well as athlete's foot, ringworm and jock itch due to Epidermophyton floccosum, Trichophyton mentagrophytes, Trichophyton rubrum, and Trichophyton tonsurans.It also displays superior activity against Candida albicans than terbinafine and naftifine. Butenafine demonstrates low minimum inhibitory concentrations against Cryptococcus and Aspergillus.
There is some evidence that it is effective against dermatophyte infections of the toenails, but needs to be applied daily for prolonged periods.
Available forms
Butenafine is typically available as a 1% topical cream.Pharmacology
Like the allylamine antifungals, butenafine works by inhibiting the synthesis of ergosterol by binding to and inhibiting squalene epoxidase, an enzyme in the pathway used for creation of the sterols needed in fungal cell membranes. Lacking ergosterol, the cell membranes increase in permeability, allowing their contents to leak out. Furthermore, inhibition of squalene epoxidase leads to a toxic buildup of squalene. This double action of butenafine makes butenafine fungicidal rather than merely fungistatic.In addition to being an antifungal, butenafine is an anti inflammatory. Because fungal skin infections are often accompanied by significant inflammation, this is a desirable property. The fact that butenafine has intrinsic anti inflammatory properties is also desirable since it is not necessary to add topical glucocorticoids, which often come with undesired side effects.