Antifungal agents are medications used to treat fungal infections, which are among the most common skin disorders. These drugs may be given in topical (applied directly to the affected area) or systemic (spread throughout the entire body) form to treat invasions of fungi (a plant-like organism) into areas of the body, such as the toes, groin, under the breasts, scalp or nails. In some cases, antifungal agents are used to prevent fungal infections in people who are at risk, including AIDS patients, cancer patients and individuals taking immunosuppressants.

In most cases, topical antifungal agents are used to treat minor infections because they can be directly applied to the affected area and tend to have fewer side effects than systemic antifungal agents. Most fungi typically reside in the top, dead layer of skin cells, where they are vulnerable to topical agents. These drugs are available in both over-the-counter and prescription formulations. They are sometimes combined with topical steroids and/or antibacterial agents.

Typically, topical antifungal agents are applied to the infected area once or twice a day. Treatment normally continues for seven to 10 days, though patients should always follow the directions from their physician or the product's manufacturer. In some cases, topical medications may have to be applied over long periods of time before an infection is effectively treated.

Some types of topical medications (e.g., ciclopirox) take the form of a lacquer (polish) that can be painted directly onto the fingernails or toenails. This form of antifungal agent generally must be used for a year or more.

More severe forms of fungal infection – particularly of the scalp and nails – are treated with systemic antifungal agents, which may be used in combination with topical agents for several weeks. Systemic forms of the drug may also be recommended for extensive infections, infections that fail to respond to topical antifungals and infections that affect hair-bearing areas. Taken orally or intravenously, systemic agents are prescription medications that have a higher risk of side effects than topical antifungals. As a result, some physicians require that patients taking systemic antifungal agents be monitored with blood tests to ensure that liver or kidney damage has not occurred.

Patients who use antifungal agents should closely follow their physician’s recommendations about proper use. In some cases, patients stop taking their medication because the skin appears to have cleared. However, the infection may remain active and is more likely to worsen in patients who stop treatments before they are complete.