Lamisil has been approved as a treatment for nail fungal infections (onychomycosis). Lamisil leads to the death of the fungal cells that cause onychomycosis, as demonstrated by in vitro studies.

The course of treatment with Lamisil tablets is 12 weeks for toenail infections and 6 weeks for fingernail infections. The drug works faster than the nail grows. Therefore, it may be several months before new clear nails grow in. Lamisil is available in a once-a-day dosing with no dietary restrictions and can be taken with or without food.

The most common side effects associated with Lamisil were gastrointestinal symptoms, headaches, and rash. These were generally mild and transient in nature. Lamisil is contraindicated in individuals who are hypersensitive to terbinafine. Rare instances of symptomatic hepatobiliary dysfunction and serious skin reactions have been reported. In such cases, therapy should be discontinued.

Onychomycosis, one of the hardest to treat forms of external infection, aggressively discolors, thickens, and destroys the nail plate. An estimated 10 million individuals in the continental United States suffer from onychomycosis, an invasive infection of the nail caused by dermatophytes--fungi like Tricophyton rubrum and Tricophyton mentagrophytes.

People who work with their hands or on their feet, or those who are frequently exposed to detergents, perspiration, and water, are at high risk for contracting onychomycosis. Nail fungal infections are prevalent among the elderly, athletes, military personnel, and laborers, and may be more severe in immunocompromised patients, particularly those with HIV.