What is the use of Terbinafine (Lamisil)?

From the Guidelines

Terbinafine should be considered as the first choice of treatment for dermatophyte onychomycosis due to its higher efficacy and tolerability compared to itraconazole. The British Association of Dermatologists' guidelines for the management of onychomycosis 2014 1 recommend terbinafine as the first-line treatment, with a licensed dose of 250 mg per day for 6 weeks in fingernail and 12–16 weeks in toenail infection. Several large studies demonstrate higher efficacy rates for terbinafine in comparison with itraconazole, with complete cure rates of 55% for terbinafine compared to 26% for pulsed itraconazole at follow-up at 72 weeks 1.

Key Points to Consider

• Terbinafine is more effective than itraconazole in treating dermatophyte onychomycosis, with higher complete cure rates and lower relapse rates 1
• The recommended dose of terbinafine is 250 mg per day for 6 weeks in fingernail and 12–16 weeks in toenail infection 1
• Patients should be re-evaluated 3–6 months after treatment initiation and further treatment should be given if the disease persists 1
• Terbinafine works by inhibiting the enzyme squalene epoxidase, which disrupts fungal cell membrane synthesis by blocking ergosterol production, making it fungicidal rather than fungistatic

Important Considerations for Treatment

• Treatment should not be commenced before mycological confirmation of infection 1
• Topical treatment is inferior to systemic therapy in all but a small number of cases of very distal infection or in SWO 1
• Cure rates of 80–90% for fingernail infection and 70–80% for toenail infection can be expected with terbinafine treatment 1

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Terbinafine Overview

• Terbinafine is an allylamine antifungal agent used to treat dermatophytic infections and onychomycosis 2
• It has been shown to be effective in treating numerous fungal infections, including those caused by dermatophytes 3

Treatment Regimens

• A quarterly terbinafine pulse regimen has been proposed as a possible alternative for treating onychomycosis caused by dermatophytes 3
• Studies have compared the efficacy of terbinafine with itraconazole, and the combination of the two drugs, in treating recalcitrant dermatophytosis 4
• Terbinafine 500 mg once daily has been shown to be efficacious and safe in the treatment of patients with dermatophytosis 5

Combination Therapy

• Terbinafine has been used in combination with other antifungal agents to treat resistant or refractory mycoses, with synergistic in vitro antifungal activity 2, 6
• High-dose regimens of terbinafine have been investigated, with predicted pharmacodynamic parameters showing increased systemic exposure 6

Efficacy and Safety

• Terbinafine has been shown to have good potency against dermatophytes, but resistance to terbinafine is on the rise 5
• Adverse drug reactions related to terbinafine have been reported, with mild to moderate intensity 5
• The combination of terbinafine and itraconazole has been shown to have a higher clinical and mycological cure rate compared to monotherapy 4