What is the recommended treatment for a patient with candida onychomycosis?

Treatment of Candida Onychomycosis

Itraconazole is the first-line treatment for Candida onychomycosis, given as 200 mg daily or pulse therapy at 400 mg daily for 1 week per month, with superior efficacy and shorter treatment duration compared to alternatives. 1

First-Line Therapy: Itraconazole

Itraconazole demonstrates significantly superior efficacy over terbinafine for Candida onychomycosis, with cure rates of 92% versus 40% when both are given as pulse therapy for 4 months. 1

Dosing Regimens

• Pulse therapy (preferred): 400 mg per day (200 mg twice daily) for 1 week per month 1, 2
• Continuous therapy: 200 mg per day 1
• Minimum treatment duration: 4 weeks for fingernails, 12 weeks for toenails 1

Administration Requirements

• Must be taken with food and acidic beverages for optimal absorption 2
• Baseline liver function tests required before initiating therapy 2
• Monitor hepatic function tests when receiving continuous therapy for more than one month 2
• Monitor hepatic function tests with concomitant use of hepatotoxic drugs, including statins 2

Key Advantages

• Shorter treatment duration makes itraconazole more cost-effective and improves compliance compared to alternatives 1
• Broad-spectrum activity against both Candida species and nondermatophyte moulds 1
• Persists in nails for 27 weeks after stopping administration 3

Second-Line Therapy: Fluconazole

Fluconazole is equally effective to itraconazole for Candida onychomycosis and should be used when itraconazole is contraindicated or not tolerated. 1

Dosing Regimens

• Weekly dosing: 300 mg per week 1
• Daily dosing: 50 mg per day 1
• Minimum treatment duration: 4 weeks for fingernails, 12 weeks for toenails 1
• For severe toenail infections, 450 mg weekly for at least 6 months may be required 1, 2

Key Advantages

• Fewer drug interactions than itraconazole, as it is a weaker inhibitor of cytochrome P450 enzymes 1
• Once-weekly dosing may improve compliance in some patients 1
• High oral bioavailability with nail:plasma ratios of 1.5 to 2 at steady state 3

Common Adverse Effects

• Headache, skin rash, gastrointestinal complaints, and insomnia 1
• Adverse effects leading to treatment discontinuation occur in 20% of patients receiving 150 mg per week, increasing to 58% for higher weekly doses (300-450 mg) 1

Third-Line Therapy: Terbinafine

Terbinafine is effective for Candida onychomycosis only when given for prolonged treatment periods, making it less practical than azole antifungals. 1

Efficacy Data

• Mycological cure rates of 70% for C. albicans and 85% for C. parapsilosis after 48 weeks of terbinafine 250 mg per day 1
• Only 60% cure rate when given for 4 months 1
• Significantly inferior to itraconazole (40% vs 92% cure rates with pulse therapy) 1

When to Consider

• May be preferred for C. parapsilosis specifically, which shows better susceptibility than C. albicans 4
• Requires higher doses or longer duration compared to dermatophyte infections 4

Special Populations and Considerations

Chronic Mucocutaneous Candidiasis

• Characterized by frequent relapses and poor response to normal drug dosages 1
• High-dose therapy for long periods is recommended, though this risks development of drug-resistant strains 1
• Alternative agents include flucytosine, amphotericin, voriconazole, posaconazole, and echinocandins 1

Patients with Local Predisposing Factors

Distinguish between patients with local causes (Raynaud phenomenon, occupational exposure) versus those with immune suppression. 1

• Local causes benefit from adjunctive measures: warm hands, improved work practices 1
• These measures help both eradication and prevention of relapse 1

Critical Pitfalls to Avoid

• Do not use terbinafine as first-line for Candida onychomycosis - it requires 48 weeks of therapy versus 12-16 weeks for itraconazole 1
• Do not prescribe itraconazole to patients with heart failure due to negative inotropic effects 2
• Do not use itraconazole in patients with hepatotoxicity or active liver disease 2
• Monitor for drug interactions, particularly with statins when using itraconazole 1, 2

Adjunctive Topical Therapy

While not specifically studied for Candida onychomycosis, combination with topical antifungals may enhance outcomes:

• Amorolfine 5% lacquer applied once or twice weekly for 6-12 months 2
• Ciclopirox 8% lacquer applied once daily for up to 48 weeks 2, 5
• Combination therapy provides wider antifungal spectrum and improved fungicidal activity 2