Terbinafine is an allylamine antifungal that inhibits squalene epoxidase (also known as squalene monooxygenase) to prevent the formation of ergosterol and cause an accumulation of squalene, weakening the cell wall of fungal cells.
Terbinafine is commonly prescribed to treat fungal infections of the nails, both fingernails and toenails. This condition, known as onychomycosis, is caused by dermatophytes.
It is used to treat athlete's foot, a common fungal infection affecting the feet, which can cause itching, burning, and peeling, It is used to treat ringworm, a fungal infection of the body that presents as round, red, scaly patches on the skin.