Dr. Greene’s Answer:
Topical methods are usually ineffective, although they do work occasionally in some people. Two effective, oral medications have become the standard treatment options. Itraconazole (Sporanox) and terbinafine (Lamasil) are both FDA approved for the treatment of nail fungus. Other treatment options include griseofulvin and fluconazole. The most frequent side effects include nausea, diarrhea, and rash. As with other medications used to treat nail fungus, liver enzyme abnormalities can occur and should be monitored. The medicines work even better if part of the fungus-filled nail is filed away, perhaps by a podiatrist.
If people who are prone to fungal infections fail to keep up a preventive regimen, and their feet get moist for a prolonged period, then the fungal infection is likely to start up again. I recommend keeping the nails as dry as possible most of the time. When they do become wet, they should be dried thoroughly, perhaps even with a hair dryer.
For those who are especially prone, I recommend an effective preventive routine: shoes that breathe, cotton socks, athlete’s foot powder (any brand) in the shoes, Fungoid Tincture on the nails before bed, and Lamisil cream to the whole foot once a week.