Terbinafine
Terbinafine is an allylamine antifungal medication that inhibits squalene epoxidase. It is used mainly for fungal infections of the nails and skin.
Squalene epoxidase: An enzyme in sterol synthesis that converts squalene into 2,3-oxidosqualene. Terbinafine inhibits this enzyme, disrupting fungal membrane sterol production.
Onychomycosis: A fungal infection of the nails, most often caused by dermatophytes. Oral terbinafine is a common treatment for dermatophyte nail infection.
Fungal infection: A disease caused by fungi infecting or growing on a host’s tissues. Terbinafine treats fungal infections, but its usefulness depends on the organism and site.
Hepatotoxicity: Liver injury caused by exposure to a drug, chemical, or other substance. Rare serious liver injury is a key safety concern with oral terbinafine.
Ergosterol: The principal sterol in fungal cell membranes, helping maintain their structure and function. Blocking its synthesis weakens fungal membranes and contributes to terbinafine’s action.
Tinea corporis: A dermatophyte infection of the body’s glabrous skin, often forming ring-shaped patches. Topical terbinafine can treat localized cases of this skin infection.
Dermatophytosis: An infection of keratinized tissue caused by dermatophyte fungi. Many of terbinafine’s standard indications are forms of dermatophytosis.
Cytochrome P450 2D6: A liver enzyme that metabolizes many medicines and is inhibited by some drugs. Terbinafine inhibits this enzyme and can raise concentrations of certain co-administered medicines.
Squalene: A lipid precursor used in the biosynthesis of sterols, including cholesterol and ergosterol. Terbinafine’s enzyme blockade causes squalene to accumulate inside susceptible fungal cells.
Tinea pedis: A dermatophyte infection of the feet, commonly called athlete’s foot. Topical terbinafine is widely used for this common superficial infection.