Terbinafine: Price, Dosage & Where to Buy

Terbinafine is an allylamine antifungal medicine used mainly for fungal infections affecting fingernails or toenails. Oral terbinafine requires a prescription in the United Kingdom, while topical cream, liquid and spray forms are also available. Generic terbinafine has been available since 2007-07-02, helping pharmacists identify it as an established treatment option.

Terbinafine is an allylamine antifungal. It interferes with an enzyme that fungi need to make ergosterol, an essential part of their cell membrane. Blocking this process causes damaging changes within the fungal cell and prevents the fungus from growing normally.

For nail infections, oral terbinafine reaches the nail as it grows, allowing treatment to act against dermatophytes within or beneath the nail. The visible nail may continue to look affected for some months after the fungal infection has cleared because healthy nail needs time to grow out.

Terbinafine tablets are indicated for onychomycosis, a fungal infection of a fingernail or toenail caused by dermatophytes. This condition is also called tinea unguium. Before oral treatment starts, appropriate nail specimens may be tested using potassium hydroxide preparation, fungal culture or nail biopsy to confirm the diagnosis.

Terbinafine is also available in topical cream, liquid and spray forms, although the tablet label specifically describes treatment for dermatophyte nail infection. Nail appearance may take some months to improve after the fungus has cleared and treatment has ended, because healthy nail must grow out.

The label lists cream and spray containing 1 g/100 g, liquid containing 0.01 g/mL, and tablets containing 250 mg. Before oral treatment, the label lists assessment for evidence of chronic or active liver disease and liver function testing. The usual starting dose is one 250 mg tablet once daily for fingernail onychomycosis.

The label lists 6 weeks for fingernail onychomycosis. The usual starting dose is one 250 mg tablet once daily for toenail onychomycosis.

The label lists 12 weeks for toenail onychomycosis. The label notes that the optimal clinical effect may be seen some months after treatment ends, as healthy nail grows out.

Store terbinafine tablets at 20° to 25°C in a tight container and protect them from light, as directed on the label. Keep the medicine in its original packaging where possible and away from children. Follow the product label for storage of cream, liquid or spray forms.

A missed dose means one scheduled dose has not been taken. General pharmacy advice is to take the missed dose when remembered unless it is nearly time for the next scheduled dose, then omit the missed dose and continue with the regular schedule.

A double dose should not be used to make up for a missed dose. A pharmacist can advise if several doses have been missed or if there is uncertainty about the schedule.

Available data from postmarketing cases in pregnant women are insufficient to evaluate the risk of major birth defects, miscarriage or adverse maternal or fetal outcomes. Animal studies did not show malformations or fetal harm at the doses described in the label.

After oral administration, terbinafine is present in human milk, but there are no data on effects on the breastfed child or milk production. Pregnancy or breastfeeding should be discussed with a doctor or pharmacist.