Treatment for Onychomycosis (Fungal Nail Infection)
Terbinafine 250 mg once daily for 12 weeks is the first-line treatment for toenail onychomycosis due to its superior efficacy, fungicidal action, and lower relapse rates compared to other antifungal agents. 1
Diagnostic Confirmation
Before initiating treatment:
- Obtain appropriate nail specimens for laboratory testing (KOH preparation, fungal culture, or nail biopsy) to confirm the diagnosis of onychomycosis 2
- Identify the causative organism, as treatment effectiveness varies by pathogen
First-Line Treatment
Oral Terbinafine
- Dosage: 250 mg once daily
- Duration:
- Toenails: 12 weeks (standard)
- Fingernails: 6 weeks 1
- Efficacy: Clinical studies show 71-82% cure rates at 48 weeks after 12 weeks of treatment 3, 4
- Mechanism: Fungicidal action against dermatophytes (most common cause of onychomycosis)
- Monitoring: Baseline liver function tests and complete blood count recommended before starting treatment 1
Alternative Oral Treatments
When terbinafine is contraindicated or ineffective:
Itraconazole
- Dosage: Either 200 mg daily for 12 weeks continuously OR pulse therapy (400 mg daily for 1 week per month for 3 months) 1
- Best for: Candida onychomycosis (may be more effective than terbinafine for this specific pathogen) 1
- Caution: More drug interactions than terbinafine 1, 5
Fluconazole
- Dosage: 150-450 mg once weekly for at least 6 months 1
- Note: Not FDA-approved specifically for onychomycosis
- Efficacy: Lower efficacy rates compared to terbinafine 1, 5
Topical Treatments
For mild cases or when oral therapy is contraindicated:
Ciclopirox 8% Nail Lacquer
- Application: Once daily for up to 48 weeks 6
- Efficacy: 34% mycological cure rate and 8% clinical cure rate 1
- Note: Requires removal of unattached, infected nail as frequently as monthly by a healthcare professional 6
Other Topical Options
- Amorolfine 5% nail lacquer: First-line topical treatment for mild to moderate cases (~50% mycological cure rate) 1
- Efinaconazole 10% solution: Applied once daily for 48 weeks (~50% mycological cure rate) 1
Special Populations
- Diabetics: Consider topical treatments for mild-to-moderate infections; terbinafine preferred due to lower risk of drug interactions 1
- Immunosuppressed patients: Topical options when systemic therapy is contraindicated; terbinafine or fluconazole preferred over itraconazole 1
- Pediatric patients: Terbinafine dosing based on weight; 6 weeks for fingernails, 12 weeks for toenails 1
Treatment Considerations
- Recent research (2023) confirms that continuous terbinafine therapy (250 mg daily for 12 weeks) is significantly more effective than pulse dosing, with clinical cure rates of 76.67% versus 26.67% 7
- Treat any associated tinea pedis (athlete's foot) to prevent reinfection 1
- Treat all infected family members simultaneously 1
Management of Treatment Failure
If infection persists after initial treatment:
- Consider partial nail removal plus antifungal therapy
- Try alternative antifungal drug
- Complete nail avulsion combined with antifungal therapy may be necessary 1
Prevention
- Keep nails short
- Avoid sharing nail clippers
- Wear protective footwear in public areas
- Apply antifungal powders in shoes and on feet
- Wear cotton, absorbent socks 1