Emerging Concepts In Treating Onychomycosis
Transungual laser therapy (TLT, Arpida) is a new device which makes partial micro-holes to the dorsal nail plate. This facilitates the permeation of terbinafine to the ventral side of the nail.25 Patients then apply a daily topical formulation of a terbinafine lacquer solution and ethanolic liquid on a daily basis. A European regulatory agency has initiated a phase III clinical trial to evaluate the efficacy, safety and tolerability of the TLT therapy.
Keraderm is creating a UVC device that offers two to four phototherapy treatments using a germicidal light. The treatment uses UVC rays, which are shorter than UVA and UVB rays. Microorganisms are very sensitive to UVC light and therefore only small amounts of UVC light can make microorganisms harmless. The radiation that the nail bed experiences is approximately equal to 20 minutes of sun exposure.
With respect to current clinical trials, the FDA has designated this device as having a non-significant risk. In the pilot trial, there were no significant side effects and 73 percent of those treated showed significant improvement in their nails.26
The device will be introduced in 2010 at approximately $100 for several treatments. The goal is to eventually only need one treatment for about $100. Keraderm’s research with this device has been published in the peer-reviewed British Journal of Dermatology and presented at the 2007 World Congress of Dermatology.26,27
Talima Therapeutics is working on a micro-implant to deliver a broad-acting time release antifungal molecule to the site of the nail infection. One would place the implant in a non-invasive manner with an applicator at the target site.28 Phase III clinical trials are currently underway in the U.S. to determine the safety and efficacy of the micro-implant. This technology has the potential to deliver high and sustained therapeutic levels of drug to the diseased area, thereby minimizing blood levels of the drug by up to a thousand-fold in comparison to conventional administration.
A new device called the Toemate (Innovation Biomedical Devices) reportedly treats onychomycosis by heating (40ºC max) a viscous antifungal liquid through the keratin in the nail plate. The theory is that heat will increase kinetic energy and facilitate drug absorption.
When keratin is heated, it has a tendency to absorb water into its structure and will absorb antifungal medication attached to absorbed fluid. Applying heat increases the rate and depth of this absorption by increasing the space between molecular bonds. This device is currently undergoing clinical trials at Temple University.29
Dr. Mozena is in private practice at the Town Center Foot Clinic in Portland, Ore. He is a Fellow of the American College of Foot and Ankle Surgeons and is board certified in foot and ankle surgery.
Dr. Mitnick is in private practice at Town Center Foot Clinic in Portland, Ore.
For further reading, see “Treating Fungal Infections,” a March 2004 supplement to Podiatry Today, “Managing Onychomycosis,” a June 2004 supplement, or “A Guide To Treatments For Onychomycosis” in the August 2003 issue.
For other related articles, please visit the archives at www.podiatrytoday.com.