Terbinafine is an antifungal medicine used to treat fungal infections such as athlete's foot and ringworm. It may be taken orally or applied topically and is available by prescription only in some countries, and over the counter in others. The trade names may differ from country to country, depending on the manufacturer.
Fungal infections can occur on almost all parts of the body and are named accordingly. Tinea is caused by a dermatophyte infection. Athlete's foot, an extremely common condition seen especially in people who use shared showers, is medically called tinea pedis. Ringworm, a condition that causes a halo-like elevated rash with a clearing in the middle, may affect any part of the body. When it affects the scalp, it is called tinea corporis.
Jock's itch, or tinea cruris, affects the groin and occurs frequently in sportsmen, especially those who wear sporting equipment. Tinea unguim affects the nails of either the hands or feet or both and requires long-term treatment to eradicate it due to the slow-growing nature of nails. There are a number of less common tinea infections too, which may be treated with terbinafine. All of them are highly contagious and can be uncomfortable and distressing.
Fungi produce ergosterol, which is a substance essential for making their cell membranes. Terbinafine blocks the production of ergosterol so that the fungi cannot create whole cell membranes, which essentially kills them. Depending on the site of infection, the length of treatment may differ and determine whether topical or oral therapy is necessary.
In most cases, topical terbinafine is used first, but if the infection is widespread or resistant to topical therapy, systemic, or oral, terbinafine may be used. It is very important to complete the course of oral or topical treatment even if all signs of the fungal infection seem to be gone, to ensure complete eradication of the fungal infection.
Various forms of topical preparation and strengths of oral treatment are available. In most countries the topical preparation is available over the counter, and the oral preparation may require a prescription from a medical doctor. Dosage and duration differs according to the site and severity of the fungal infection.
As with any medication, terbinafine may interact with other drugs and have side effects. Any concomitant medication or disease condition should be discussed with the doctor or pharmacist before use. Pregnancy, desired pregnancy or lactation should also be considered before using terbinafine. Should any untoward adverse effects occur during treatment with terbinafine, immediate medical attention should be sought.