What is Lamisil Cream?
Lamisil cream is a topical antifungal medication containing 1% terbinafine hydrochloride that is used to treat superficial fungal skin infections, particularly those caused by dermatophytes. 1
Mechanism of Action
Terbinafine works by inhibiting squalene epoxidase, an enzyme essential for fungal cell wall synthesis. This dual action depletes ergosterol (fungistatic effect) and causes squalene accumulation (directly fungicidal). Terbinafine is the only topical antifungal with true fungicidal properties against dermatophytes, making it particularly potent against Trichophyton rubrum and T. mentagrophytes. 2
Because terbinafine is strongly lipophilic, it distributes exceptionally well into skin and persists after treatment completion, allowing for shorter treatment durations compared to other topical antifungals. 2
Approved Uses
Lamisil cream is FDA-approved for:
- Athlete's foot (tinea pedis) - particularly effective for interdigital infections
- Jock itch (tinea cruris)
- Ringworm (tinea corporis)
Clinical Efficacy
The evidence strongly supports short-duration therapy with Lamisil cream:
For tinea corporis/cruris: Once-daily application for just 7 days achieves 84.2% mycological cure rates, significantly superior to placebo (23.3%). 3
For interdigital tinea pedis: Once-daily treatment for 1 week produces 91.4% mycological cure rates maintained for 7 weeks post-treatment, compared to 37.1% with vehicle. 4
Compared to clotrimazole: One week of terbinafine twice daily is more effective than 4 weeks of clotrimazole twice daily (93.5% vs 73.1% mycological cure). 5
Application Instructions
- Apply once or twice daily (depending on formulation) for 7 days only for most superficial dermatophyte infections
- For external use only
- Do not use on nails, scalp, in/near mouth or eyes, or for vaginal yeast infections 1
Important Limitations
Terbinafine has lower activity against Candida species than azole antifungals, so it should not be first-line for yeast infections. 2
Emerging resistance: Recent data shows over 60% of T. mentagrophytes isolates demonstrate terbinafine resistance in some regions, particularly with T. indotineae strains. 6, 7 If treatment fails, consider fungal culture with susceptibility testing and alternative agents like griseofulvin or itraconazole.
Safety Profile
- Most common side-effects: local irritation, erythema (generally mild)
- Stop use if excessive irritation occurs
- Keep out of eyes; rinse thoroughly if contact occurs
- Safe for external use; keep out of reach of children 1
The short 7-day treatment duration significantly improves patient compliance compared to traditional 4-week antifungal regimens, while maintaining superior cure rates. 3, 4