Product: Onychomycosis update: New antifungal therapies, both systemic and topical, are on the horizon

October 1, 2008

Emerging therapies that treat onychomycosis are expected to help patients who do not respond to currently available therapies. Both systemic and topical, these new therapies also will have shorter treatment periods, which can possibly improve patient compliance.

Key Points

"There is a great unmet need for new antifungal agents," says Joel Schlessinger, M.D., a board-certified dermatologist and general cosmetic surgeon; immediate past president of the American Society of Cosmetic Dermatology and Aesthetic Surgery; and president of http://LovelySkin.com/. "There are gaps where the older agents are concerned."

Current therapies

Itraconazole is usually administered at 200 mg twice daily for one week per month, with the drug being detectable in nail clippings for up to one year after the last administration.

Fluconazole also has demonstrated efficacy in treating onychomycosis, but it is usually not a first-line therapy.

"Terbinafine treats 82 percent of patients at best for their particular type of fungal ailment," Dr. Schlessinger tells Dermatology Times. "It does not result in enough improvement that people are satisfied in all cases. We would like to see a treatment that can improve the odds of clearance with a better treatment regimen, if possible. "

Surgery for onychomycosis has not been met with success, Dr. Schlessinger says. "Surgical treatment does not result in significant improvement and often leaves the patient with significant deformities of the nails."

Emerging treatments

An emerging systemic therapy, albaconazole provides broad-spectrum coverage against fungal infections. As a class of agents, azoles provide broad-spectrum coverage and are safe to use compared to other antifungal compounds.

Another emerging systemic therapy is posiconazole, which is thought to have more activity than currently available azoles. When comparing posiconazole head- to-head against itraconazole and fluconazole in in vitro studies, MIC values were lower than those of the older agents.

One of the troubling side effects with terbinafine is a loss of taste, Dr. Schlessinger says. "That problem is unique to terbinafine, but is not a terribly common side effect," he explains.

Because the standard therapies for onychomycosis are systemic agents, there is the potential for interactions with other oral medications, according to Dr. Schlessinger.

Given that potential, topical formulations would be an advantageous treatment choice, for they would avoid interaction with other systemic agents.

Several formulations that would permeate the nail and treat the infection of the nail and surrounding tissues are currently under investigation, Dr. Schlessinger says.

"The hope is that the topical formulations will treat nail fungus effectively in the future. If the formulations can lead to shorter treatment time and better compliance, it would be beneficial," he adds.

Unfortunately, standard therapies have relatively long treatment periods.

"It has gotten better as time goes on, but we are not at the point where it's like treating a strep throat," Dr. Schlessinger says.

Stopping the spread

Onychomycosis can affect more than one member of a family, Dr. Schlessinger says. "It's relatively common to see a husband and wife or whole family affected by the condition, especially if they are sharing the same bathroom.

"They need to ensure that shoes and other foot items are cleaned thoroughly, or discarded if they can't be cleaned thoroughly," he adds.

Frequenting health clubs and using the communal showers in such facilities represents a common source of nail fungal infection.

"Patients should wear water slippers when they use communal showers or use showers in hotels," Dr. Schlessinger says.

Services such as manicures and pedicures should also be avoided if patients are infected with fungus.

"Many patients who have onychomycosis have these (manicures and pedicures) to cover up the problem, and it's only making it worse," Dr. Schlessinger says.