What medications are used to treat onychomycosis (nail fungus) of the hands?

Treatment of Fingernail Onychomycosis (Hand Nail Fungus)

For fingernail onychomycosis, oral terbinafine 250 mg once daily for 6 weeks is the first-line treatment, with itraconazole pulse therapy (400 mg daily for 1 week per month for 2 months) as the preferred alternative if terbinafine cannot be used. 1, 2

First-Line Systemic Treatment: Terbinafine

Terbinafine is the gold standard for dermatophyte fingernail infections due to its superior fungicidal activity, higher cure rates, and minimal drug interactions compared to azole antifungals. 1, 2

Dosing and Duration

• 250 mg once daily for 6 weeks for fingernail infections 1, 3
• Can be taken with or without food 2
• The drug persists in nails for 6 months after treatment completion, allowing continued antifungal activity 2

Pre-Treatment Requirements

• Obtain baseline liver function tests (LFTs) and complete blood count (CBC) before initiating therapy 1, 2
• Confirm diagnosis with laboratory testing (KOH preparation, fungal culture, or nail biopsy) 3

Monitoring During Treatment

• Monitor LFTs if patient has history of hepatitis, heavy alcohol use, or is on concomitant hepatotoxic medications 1, 2
• Re-evaluate patient 3-6 months after treatment initiation to assess response 2, 4

Contraindications

• Active or chronic liver disease (absolute contraindication) 1, 2
• Lupus erythematosus (absolute contraindication) 2
• History of allergic reaction to oral terbinafine 3

Common Adverse Effects

• Headache, taste disturbance, and gastrointestinal upset 1
• Can aggravate psoriasis and cause subacute lupus-like syndrome 1
• Rare but serious: Stevens-Johnson syndrome and toxic epidermal necrolysis 2

Second-Line Systemic Treatment: Itraconazole

If terbinafine is contraindicated or not tolerated, itraconazole pulse therapy is the preferred alternative. 1

Dosing Options

• Pulse therapy (preferred): 400 mg daily (200 mg twice daily) for 1 week per month for 2 months (2 pulses total for fingernails) 1, 5
• Continuous therapy: 200 mg daily for 12 weeks 5

Administration Requirements

• Must be taken with food and acidic beverages for optimal absorption 1, 5
• Monitor hepatic function tests at baseline and during therapy, especially with concomitant hepatotoxic drug use 1, 5

Contraindications and Cautions

• Heart failure (contraindicated due to negative inotropic effects) 5
• Hepatotoxicity or active liver disease 5
• Significant drug interactions with statins - use caution and monitor closely 5

Third-Line Systemic Treatment: Fluconazole

Fluconazole is reserved for patients who cannot tolerate both terbinafine and itraconazole. 1

Dosing

• 150-450 mg once weekly for 3 months for fingernail infections 1
• Baseline LFTs and CBC required 1
• Monitor LFTs during high-dose or prolonged therapy 1

Topical Therapy Options

Topical antifungals can be used as adjunctive therapy to systemic treatment or as monotherapy for mild, superficial infections. 1

Available Topical Agents

• Amorolfine 5% lacquer: Apply once or twice weekly for 6-12 months 1
• Ciclopirox 8% lacquer: Apply once daily for up to 48 weeks 1
• Efinaconazole 10% solution: Shows mycological cure rates approaching 50% after 48 weeks 5, 6
• Tioconazole 28% solution: Apply twice daily for 6-12 months 1

When to Consider Topical Therapy

• Mild disease with limited nail involvement 6
• Superficial and distal onychomycosis 1
• Patients in whom systemic therapy is contraindicated 1
• Combination with systemic therapy enhances cure rates through antimicrobial synergy 5

Treatment Algorithm

1. Confirm diagnosis with laboratory testing (KOH, culture, or biopsy) before initiating treatment 3
2. Assess severity: Determine extent of nail involvement and presence of matrix involvement
3. Check for contraindications: Review liver function, cardiac history, and current medications
4. First choice: Terbinafine 250 mg daily for 6 weeks 1, 2
5. If terbinafine contraindicated: Itraconazole pulse therapy (400 mg daily for 1 week/month × 2 months) 1
6. If both contraindicated: Fluconazole 150-450 mg weekly for 3 months 1
7. Consider adding topical therapy for enhanced efficacy 5

Important Clinical Pearls

• Fingernail infections respond much better than toenail infections to shorter treatment durations 7
• Clinical improvement lags behind mycological cure - healthy nail growth takes months after treatment completion 3
• Griseofulvin is not recommended due to lower efficacy (30-40% cure rates), longer treatment duration (6-9 months), and higher relapse rates 1, 5
• Terbinafine has minimal drug interactions compared to azole antifungals, making it safer for patients on multiple medications 2, 4
• The main interaction concern with terbinafine is drugs metabolized by cytochrome P450 2D6 (certain antidepressants, beta-blockers, antiarrhythmics) 2

Monitoring Treatment Response

• Re-evaluate at 3-6 months after starting treatment 2, 4
• If disease persists, a new treatment course can be started without additional waiting period 2
• Assessment should include both mycological testing (KOH and culture) and clinical examination 5
• Monitor for at least 48 weeks from start of treatment to identify potential relapse 5