Pharmacology of the allylamines

The allylamines are a new class of antifungal drugs that inhibit ergosterol synthesis at the level of squalene epoxidase. These agents are highly selective for the fungal enzyme and have a minimal effect on mammalian cholesterol synthesis. Naftifine, the original member of the allylamine series, possesses only topical activity, whereas the naftifine analog terbinafine is active both topically and orally. In vitro, terbinafine is exceptionally active against dermatophytes, molds, and dimorphic fungi in which it exerts a fungicidal action. This in vitro profile is reflected by the clinical effectiveness of this allylamine in the treatment of dermatophyte infections. When given orally, terbinafine is well absorbed and rapidly and extensively distributed to the skin and sebum in concentrations that exceed the minimum inhibitory concentrations of these organisms by several orders of magnitude.