From the Guidelines
The recommended dose of terbinafine (Lamisil) for treating onychomycosis is 250 mg orally once daily, with treatment durations of 6 weeks for fingernail infections and 12–16 weeks for toenail infections. This recommendation is based on the British Association of Dermatologists' guidelines for the management of onychomycosis 2014 1, which suggests that terbinafine should be considered as the first choice for treating dermatophyte onychomycosis due to its higher efficacy and tolerability compared to itraconazole.
Key Considerations
- Terbinafine is an allylamine antifungal that works by inhibiting squalene epoxidase, disrupting fungal cell membrane synthesis 1.
- The medication can be taken with or without food and should be continued for the full prescribed duration, even if improvement is seen earlier, to prevent recurrence.
- Patients should be aware that complete nail clearing may take several months after completing therapy as the healthy nail grows out.
- Liver function tests are recommended before starting treatment due to the rare risk of hepatotoxicity 1.
- Terbinafine is generally preferred over alternatives like itraconazole for dermatophyte nail infections because of its higher cure rates and fewer drug interactions 1.
Treatment Duration and Monitoring
- For fingernail infections, the typical treatment duration is 6 weeks.
- For toenail infections, the treatment duration is 12–16 weeks due to the slower growth rate of toenails and deeper fungal penetration.
- Patients should be re-evaluated 3–6 months after treatment initiation, and further treatment should be given if the disease persists 1.
From the FDA Drug Label
DOSAGE AND ADMINISTRATION Fingernail onychomycosis: One 250 mg tablet, once daily for 6 weeks. Toenail onychomycosis: One 250 mg tablet, once daily for 12 weeks
The recommended dose of terbinafine (Lamisil) for treating onychomycosis is:
- 250 mg once daily for 6 weeks for fingernail onychomycosis
- 250 mg once daily for 12 weeks for toenail onychomycosis 2
From the Research
Recommended Dose of Terbinafine for Onychomycosis
The recommended dose of terbinafine (Lamisil) for treating onychomycosis is:
- 250 mg/day for 12 or 16 weeks, as shown in studies 3, 4
- Alternatively, a pulse regimen of 500 mg/day for 7 days every 3 months, totaling four treatments, has also been found to be effective 5
- Another study suggests that a combination of oral terbinafine 250 mg/day for 12 weeks with ciclopirox nail lacquer topical solution, 8% may also be an effective treatment option 6
Efficacy of Terbinafine
The efficacy of terbinafine in treating onychomycosis has been demonstrated in several studies, with:
- Mycologic cure rates ranging from 66.7% to 81% 3, 6, 7
- Complete cure rates ranging from 35% to 42% 3, 7
- Clinical cure rates ranging from 40% to 46% 3, 6
Safety and Tolerability
Terbinafine has been found to be generally well-tolerated, with: