Onychomycosis

Onychomycosis is a common infection of the fingernails and toenails caused by naturally occurring skin fungi. Mechanical pressure (such as tight shoes) and advancing age make the nails more prone to infection. Not only does the nail become infected, but the nail bed beneath the skin is also diseased. As a result, topical medications such as creams are not effective. Involved nails are usually deformed and discolored as a result. The poor appearance of these nails causes many people to seek treatment. Oral antifungal medications have been widely advertised lately as treatment for onychomycosis. The reasons for this are twofold:

1. only recently has effective medication become available;
2. government restrictions on pharmaceutical advertising have been relaxed.

The two medications approved for treatment by the FDA are Sporanox (itraconazole) and Lamisil (terfenabine). Sporanox is taken either daily or twice a day for a week, followed by a 3 week pause; Lamisil is taken daily. Both medications are prescribed for a 3 month course. Potential side effects of Sporanox and Lamisil include gastrointestinal upset, liver damage, headache, fever, dizziness, ankle swelling, decreased blood potassium levels, rash, and hives. Sporanox has serious interactions with over one dozen different medications including potentially life-threatening heart arrhythmias when taken in conjunction with Propulsid (cisapride) or Hismanal (astemizole). Periodic blood tests for liver function testing are recommended when medications are taken daily.

Results of controlled trials to evaluate these medications have shown that at best they work 50% of the time. Recurrence of onychomycosis after treatment may occur. Toenail fungus is usually considered a cosmetic, rather than a medical problem, and is generally not covered by health plans. A 3 month course of therapy costs $300-$500.

If you wish to take medications for onychomycosis, we ask that you weigh the cost, risks, and benefits of treatment with antifungal regimens. At this time, since treatment is both expensive and relatively ineffective, we physicians at General Internal Medicine are reluctant to prescribe these medications.