What is the diagnosis and treatment for Onychomycosis (Fungal infection of the nail)?

From the Guidelines

Onychomycosis should be treated with itraconazole as the first-line treatment, given its shorter treatment duration and higher efficacy compared to terbinafine, as demonstrated in the most recent study 1.

Treatment Options

The treatment of onychomycosis depends on the severity and type of infection. For mild to moderate cases, topical treatments like ciclopirox 8% nail lacquer applied daily for up to 48 weeks can be effective, with a mycological cure rate of 34% and a clinical cure rate of 8% 1. However, for more severe or resistant infections, oral medications are recommended.

Oral Medications

The most effective oral medications for onychomycosis are itraconazole and terbinafine. Itraconazole should be considered the first-line treatment, given its shorter treatment duration and higher efficacy compared to terbinafine, as demonstrated in the most recent study 1. Itraconazole can be given at a dose of 200 mg per day or as pulse therapy (400 mg per day for 1 week each month), while terbinafine is given at a dose of 250 mg per day for 6 weeks (fingernails) or 12 weeks (toenails).

Prevention and Management

Complete cure requires patience as nails grow slowly, with fingernails taking 4-6 months and toenails 12-18 months to fully replace. The infection thrives in warm, moist environments, so keeping nails dry, wearing breathable footwear, avoiding walking barefoot in public areas, and not sharing nail tools can help prevent recurrence. Diabetic patients or those with compromised immune systems should seek treatment promptly as complications can be more serious.

Key Considerations

• The fungus invades the nail plate and nail bed, causing discoloration, thickening, and brittleness, which is why long-term treatment is necessary to completely eradicate the infection.
• The most recent study 1 demonstrates the efficacy of itraconazole in treating onychomycosis, making it the preferred treatment option.
• Topical treatments like ciclopirox 8% nail lacquer can be effective for mild to moderate cases, but oral medications are recommended for more severe or resistant infections.

From the FDA Drug Label

1 INDICATIONS AND USAGE Terbinafine tablets, USP are indicated for the treatment of onychomycosis of the toenail or fingernail due to dermatophytes (tinea unguium).

INDICATIONS AND USAGE (To understand fully the indication for this product, please read the entire INDICATIONS AND USAGE section of the labeling.) Ciclopirox Topical Solution, 8%, (Nail Lacquer), as a component of a comprehensive management program, is indicated as topical treatment in immunocompetent patients with mild to moderate onychomycosis of fingernails and toenails without lunula involvement, due to Trichophyton rubrum

Onychomycosis Treatment Options:

• Terbinafine (PO) is indicated for the treatment of onychomycosis of the toenail or fingernail due to dermatophytes (tinea unguium) 2.
• Ciclopirox (TOP) is indicated as topical treatment in immunocompetent patients with mild to moderate onychomycosis of fingernails and toenails without lunula involvement, due to Trichophyton rubrum 3.

From the Research

Causes and Prevalence of Onychomycosis

• Onychomycosis is a common disease of the nail unit caused by dermatophytes, yeasts, and molds 4, 5.
• The prevalence of onychomycosis in the world's population is 2% to 18% or higher and accounts for approximately 50% of all nail disorders 5.
• Mycotic nail infections do not always resolve spontaneously and may have a substantial impact on the patient's quality of life 4.

Treatment Options for Onychomycosis

• Current treatment modalities for onychomycosis include surgery, topical antifungals, and oral antifungals 4.
• Surgery is generally not recommended as first-line therapy 4.
• Broad-spectrum topical and oral antifungal agents are the most frequently used treatments 4.
• Topical treatment is well tolerated but is usually not effective because of poor patient compliance and inadequate penetration of the nail 4.
• Oral antifungals are more successful but carry greater risks 4, 6.

Effective Oral Antifungal Agents

• Itraconazole and terbinafine are both safe and effective first-line agents, with reported overall cure rates of 50-90% for dermatophyte-related onychomycosis 4, 7.
• Terbinafine produces the best results when a dermatophyte is the pathogen 7.
• For Candida and nondermatophyte infections, the azoles, mainly itraconazole, are the recommended therapy 7.

Combination Therapy for Onychomycosis

• Combining oral and topical antifungal drugs is associated with higher success rates 8.
• The combination of terbinafine with amorolfine tends to be more effective than terbinafine in conjunction with ciclopirox 8.
• Additive or synergistic modes of action are expected to enhance treatment success rates 8.

Safety Considerations for Onychomycosis Treatment

• Systemic antifungals offer greater efficacy for onychomycosis treatment but are limited by risks of systemic toxicity and drug-drug interactions 6.
• The risk of terbinafine-induced hepatotoxicity is negligible in healthy patients 6.
• Systemic therapies, especially azole antifungals, are associated with numerous drug-drug interactions, some of which are life-threatening and fatal 6.