Systemic medications at the moment are the primary treatment for stubborn onychomycosis, says a dermatologist based in Sewickley, Pa.
The true incidence of onychomycosis is not really known. One study indicates that about 15 percent of the U.S. population has been affected. However, many cases go undiagnosed or misdiagnosed, he says.
"Also, the HIV population is probably higher at about 25 percent," says Dr. Bikowski, who also is clinical assistant professor of dermatology at the Ohio State University, Columbus, Ohio.
"In this population, these people are coming into contact with it all the time, and eventually they do not have the immune response to fight against it," Dr. Bikowski tells Dermatology Times.
Topical vs. systemic
"Overall, topical medications are not effective because there is nothing that truly penetrates the nail plate," says Dr. Bikowski, who has modified an older treatment and is now using topicals in a new fashion.
"I have had some success with the subungual installation of an alcohol-based topical antifungal solution, such as Exelderm (sulconazole) solution. If the distal half of the great toe nail is involved, I instruct the patient to place the foot in an upright position, and then place one or two drops between the nail plate and the nail bed. Gravity then carries the alcohol-based anti-fungal solution to the site of infection," Dr. Bikowski says.
Systemic medications are currently the primary treatments for onychomycosis.
"The most effective systemic treatment is terbinafine (Lamisil, Novartis), which has an overall clinical success rate of 77 percent versus about a 35 percent cure rate for intraconazole," Dr. Bikowski says.
Research has shown that terbinafine is a safer medication, he says.
"There are no drug interactions of any clinical significance with terbinafine. With intraconazole, there are drug interactions of clinical significance and also a concern of congestive heart failure," he says.
Terbinafine treatment of onychomycosis of the toenail consists of 250 mg per day for three to four months. If the entire nail is destroyed, four months; lesser cases require about three months," Dr. Bikowski says. "For intraconazole, the course is a 200 mg a day for 12 weeks."
Yet, Dr. Bikowski notes that when therapy is complete, the nails will not immediately return to their natural beauty.
"When patients finish either the three-month or four-month course of either drug, the nail is still going to be abnormal in appearance, because it takes about 12 months for a toenail to grow out. Therefore, the fungus must be killed or suppressed, and then the patient has to wait until a new nail that has not become infected to grow out," he explains.