Two of the three latest treatments for fungal nail infections — itraconazole (brand name Sporanox), terbinafine (Lamisil), and fluconazole (Diflucan) — have been on the market for more than a year, and they have proved to work quickly, safely, and less expensively than the medications previously prescribed by dermatologists. The treatment of onychomycosis (fungal infection of the nail) has changed markedly in the past several years, and treatments are being prescribed more often. This is because there has been an increase in the incidence of onychomycosis, especially in people with conditions that make them prone to fungal nail infections, patients with AIDS, for example, or patients who are immuno-suppressed from an organ transplant, and patients taking high dosages of antibiotics and cortisone. Therefore, it is important that we take a fresh look at the treatments for this condition.

Diflucan is the only one of the three medications that hasn’t yet been approved as a nail fungus treatment by the FDA. Accurate diagnosis is very important because the treatments for other conditions that resemble fungus — such as nail psoriasis — are quite different.

All three of the new drugs work by interfering with the production of a chemical called ergosterol, which is necessary for the survival of the fungus organisms. When the production of this chemical is interrupted, the fungus’s protective outer capsule cannot be manufactured, causing the fungus to die.

Doctors also have better methods to diagnose fungal nail infections now than ever before. In addition to the conventional scraping and culture techniques used for many years, we are now doing biopsies of the nail.

Not only is a fungus-infected nail uncomfortable and unattractive, the infection affects the nail’s function — making it difficult to pick up small objects or manipulate machinery, for example. Infected toenails can interfere with walking.

One of the problems with the old antifungal agents is that they required a long treatment time. Using the old medications, toenails had to be treated for as long as 12 months and fingernails for as long as six months in order to get a significant response. The treatment time on the new medications is much shorter. These new drugs get to the nail as quickly as 7-21 days from the start of the treatment. Unlike the old drugs, the new drugs remain in the nail after treatment is discontinued and continue to work long after the patient quits taking the drug.

Shorter treatment time is desirable because it’s considered safer. A shorter medication period can reduce the incidence of unwanted side effects, which occur only in about 10%—12% of patients on the medications. Most of the side effects, however, are minor: stomach upset, headache, or allergic reactions, such as a rash.

A serious potential side effect of these drugs is damage to the liver, but it is a rare occurrence with the new agents. The possibility of liver damage would most likely be detected by the blood test administered during the course of treatment. If a doctor prescribes one of the new antifungals, he or she will probably take blood tests before and during the treatment. If there is a liver problem, the blood test may become abnormal and the antifungal treatment can then be discontinued.

Another significant factor about the new antifungal agents is that they can be administered in a number of different ways. They may be given on a daily-dose schedule, or on what is called a pulse-dose schedule, which means the medication is taken for one week and then there is a three-week rest period, and then it is repeated for one week followed by another three-week rest period. This schedule can be prescribed for a period of several months. Finally, there is what is known as an intermittent-dose schedule, where the medication is taken only once a week for as few as eight weeks or as long as six months. The dosage method a doctor chooses for a particular patient depends on what the patient prefers. There are many dosing options with the new antifungal agents that weren’t available with the old treatments.

Before anyone takes an oral antifungal medication, it is very important that she discuss with her physician in considerable detail whether she should take any other medications. This is because there may be some drug interaction between the antifungal drug and other drugs, such as antihistamines.