MIAMI BEACH – Two new topical solutions approved in 2014 for the treatment of distal subungual onychomycosis don’t eliminate the need for oral treatment, but they do represent improvement in the options available to patients, according to Dr. Boni E. Elewski.
Oral treatments, including terbinafine, itraconazole, and fluconazole are still of value – either alone or in combination with the new solutions or other agents – for this type of onychomycosis, which is “essentially a nail bed dermatophytosis,” she said at the South Beach Symposium.
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Terbinafine has been used for 2 decades, and is probably the most commonly used treatment for onychomycosis. It is approved as a once-daily pill given for 90 days, and reportedly has a cure rate just under 40%, she said.
Itraconazole is approved as a 200-mg daily dose for 12 weeks, although most physicians use pulse dosing, prescribing 400 mg daily for a week, then for 1 week each month.
“I like this drug for my nondermatophyte patients … if you have something that you don’t think is a dermatophyte, or if they’ve failed terbinafine, this is an excellent option,” she said.
Fluconazole, her “personal favorite,” is used off label for onychomycosis, but has been shown to have good cure rates with once-weekly treatment, said Dr. Elewski of the University of Alabama at Birmingham.
“I’ll confess, I like this drug because I feel comfortable with it,” she said adding that she tells her patients to think about “Fungal Fridays” or “Toesdays” as a way to remember to take their weekly treatments.
The cure rates are quite good, she said, noting that because the nails grow so slowly, the pace of the treatment matches patient expectations. They don’t finish treatment and still have a “cruddy-looking” nail, she explained.
If any of these oral drugs are used, laboratory monitoring and periodic assessments are necessary, so treatment is a bit complicated. Adverse events remain a concern – particularly drug-drug interactions, drug eruption, cardiac issues (with itraconazole), and loss of taste (with terbinafine).
“So we do have to worry about some of these conditions, which is why having other treatments is so nice,” Dr. Elewski said.
Another reason it’s good to have more options is that no matter which drug you choose, it won’t cure everyone, she noted. Sometimes that’s because the condition is severe; patients with a dermatophyte abscess, those with very thick nails, and those with complete nail involvement associated with a nondermatophyte mold, for example, will have a poorer prognosis, regardless of which oral treatment given. Also, the condition is often complicated by concomitant disorders such as psoriasis. About 5% of patients with psoriasis have nail-only disease, and about a third of them also have onychomycosis. Others are misdiagnosed as having onychomycosis.
Alternatives that can be used alone or in combination with the oral therapies, include the two new topical solutions: efinaconazole and tavaborole, Dr. Elewski said.
Solutions are good, because you can apply them on, under, and around the nail. Both of the drugs have demonstrated effective penetration of the nail plate, allowing penetration to the nail bed where the infection exists, she noted.
The mycological cure rate with efinaconazole yields outcomes comparable to those with oral drugs.
“I think [the mycological cure] is actually the most important endpoint. Because when you want to get rid of the fungus, what do you do? You want to kill the fungus,” said Dr. Elewski, adding that mycological cure is the first sign a patient will go on to experience complete cure.
The complete cure rate is lower, but that appears to be a time-related factor. The nail takes a long time to grow, so the complete cure rate will lag behind the mycological cure rate, Dr. Elewski explained.
The other topical solution – tavaborole – is a new molecule that contains boron. Mycological cure rates in studies of the drug were in the mid-30% range, and it appears able to be used with nail polish without issues to the polish or the outcomes, she said.
In Dr. Elewski’s experience, these topicals work better than expected in clinical practice, based on the clinical trials. One patient who wasn’t eligible for the clinical trials because of a dermatophytosis, for example, was nearly clear within 5 months, and is now totally cured, she said.
“So these treatments are effective as monotherapy, but could be used as an adjunct with systemic therapy, and perhaps also in nondermatophyte cases of onychomycosis,” Dr. Elewski noted. “I think it would be a better option to pick one of these topical drugs than putting someone on a prolonged course of itraconazole if at all possible.” The safety issue would be more favorable with the topical antifungal solution, she said.