What is the treatment for persistent onychomycosis?

From the Guidelines

For persistent onychomycosis, terbinafine should be considered as the first choice of treatment due to its higher efficacy and tolerability, with a recommended dose of 250 mg per day for 12–16 weeks in toenail infection. This recommendation is based on the British Association of Dermatologists' guidelines for the management of onychomycosis 2014 1. The guidelines suggest that terbinafine is more effective than itraconazole, with higher efficacy rates and lower rates of mycological and clinical relapse.

Some key points to consider when treating persistent onychomycosis with terbinafine include:

• The treatment duration, which is typically 12–16 weeks for toenail infections and 6 weeks for fingernail infections
• The importance of re-evaluating patients 3–6 months after treatment initiation and considering further treatment if the disease persists
• The potential for intermittent or "pulse" treatment regimens, although continuous treatment is often recommended

If terbinafine is not effective or contraindicated, alternative treatments may include:

• Itraconazole 200 mg per day for 12 weeks continuously, or as pulse therapy at a dose of 400 mg per day for 1 week per month
• Combination therapy with topical antifungals, such as ciclopirox 8% nail lacquer, to improve outcomes
• Mechanical nail debridement by a podiatrist to reduce fungal load

It is also essential to advise patients on preventive measures to reduce the risk of reinfection, including:

• Keeping nails short and dry
• Wearing breathable footwear
• Using antifungal powder in shoes
• Avoiding walking barefoot in public areas

Overall, the treatment of persistent onychomycosis requires a comprehensive approach that addresses both systemic and local fungal presence, and terbinafine is a highly effective option for many patients 1.

From the FDA Drug Label

The optimal clinical effect is seen some months after mycological cure and cessation of treatment due to the time period required for outgrowth of healthy nail. In the first toenail study, for patients evaluated at least six months after achieving clinical cure and at least one year after completing terbinafine therapy, the clinical relapse rate was approximately 15%

• Treatment for persistent onychomycosis is not explicitly stated in the provided drug labels.
• However, based on the available information, terbinafine (PO) 2 has been shown to be effective in treating onychomycosis, with a clinical relapse rate of approximately 15% after completion of therapy.
• Ciclopirox (TOP) 3 is also indicated for the treatment of mild to moderate onychomycosis, but its effectiveness in treating persistent onychomycosis is not directly stated.
• No conclusion can be drawn regarding the treatment of persistent onychomycosis.

From the Research

Treatment Options for Persistent Onychomycosis

The treatment for persistent onychomycosis typically involves oral antifungal medications. The most commonly used oral antifungals are:

• Itraconazole
• Terbinafine
• Fluconazole

Dosage Regimens

The dosage regimens for these medications are as follows:

• Itraconazole: 100 to 200 mg daily for 3 months, or pulse therapy with 200 mg twice daily for 1 week per month for 3 pulses 4, 5, 6
• Terbinafine: 250 mg daily for 12 weeks 4, 7, 6, 8
• Fluconazole: 150 mg weekly for at least 6 months, or 150 mg/wk until the abnormal-appearing nail plate has grown out, typically over a period of 9 to 18 months 4, 6

Efficacy and Safety

The efficacies of these antifungal agents for dermatophyte great toenail onychomycosis treatment are:

• Terbinafine: 38% complete cure, 70% mycologic cure 7
• Itraconazole: 14% complete cure, 54% mycologic cure 7
• Posaconazole: 54.1% complete cure, 70.3% mycologic cure 7
• Fosravuconazole: 59.4% complete cure, 82.0% mycologic cure 7
• Oteseconazole: 45% complete cure, 70% mycologic cure 7 These medications are generally well tolerated, with common adverse reactions including gastrointestinal symptoms, cutaneous eruptions, and CNS effects 6

Alternative Therapies

Alternative therapies, such as posaconazole, fosravuconazole, voriconazole, and oteseconazole, have also been evaluated for the treatment of onychomycosis, although they are not yet US FDA approved for this indication 7