What are the treatment options for toenail fungus infection?

Treatment Options for Toenail Fungus Infection

Terbinafine is the first-line oral treatment for toenail fungus infection (onychomycosis), with a recommended dosage of 250 mg daily for 12 weeks for toenail infections. 1

Diagnosis Before Treatment

Before initiating any treatment:

• Mycological confirmation of infection is essential through:
  • KOH preparation
  • Fungal culture
  • Nail biopsy 2

Treatment Algorithm

First-line Treatments:

1. Oral Terbinafine:

   • Dosage: 250 mg daily
   • Duration: 12-16 weeks for toenails
   • Efficacy: 70-80% mycological cure rate 1
   • Monitoring: Baseline liver function tests and complete blood count recommended, especially with history of hepatotoxicity 1
   • Mechanism: Fungicidal action through inhibition of squalene epoxidase 1

2. Oral Itraconazole (alternative first-line):

   • Continuous regimen: 200 mg daily for 12 weeks
   • Pulse regimen: 400 mg daily for 1 week per month for 3 months (toenails)
   • Efficacy: Slightly lower than terbinafine for dermatophyte infections 1
   • Monitoring: Liver function tests recommended with pre-existing abnormalities or continuous therapy 1
   • Best taken with food and acidic pH for optimal absorption 1

Second-line Treatments:

1. Oral Fluconazole:

   • Dosage: 150-450 mg once weekly
   • Duration: At least 6 months for toenail infections
   • Consider when terbinafine or itraconazole cannot be tolerated 1
   • Weekly dosing may improve compliance 1

2. Topical Treatments (for mild cases or when oral therapy is contraindicated):

   • Ciclopirox 8% nail lacquer:

     • Applied once daily for up to 48 weeks
     • Requires removal of unattached, infected nails monthly 3
     • Best for mild to moderate cases without lunula involvement 3

   • Amorolfine 5% lacquer:

     • Applied once or twice weekly for 6-12 months
     • Useful for superficial and distal onychomycosis 1

Special Considerations

For Diabetic Patients:

• Terbinafine is preferred due to lower risk of drug interactions and hypoglycemia 1
• Onychomycosis is a significant predictor for foot ulcers in diabetics 1

For Immunosuppressed Patients:

• Terbinafine is preferred over itraconazole when patients are on antiretrovirals 1

For Treatment Failures:

• Consider nail removal in combination with antifungal therapy, especially with subungual dermatophytoma 1
• Evaluate for poor compliance, poor absorption, immunosuppression, or resistance 1

Prevention of Recurrence

• Keep nails short
• Wear protective footwear in public areas (hotels, gyms, swimming pools)
• Use absorbent powders and antifungal powders in shoes
• Consider discarding old footwear or decontaminating with naphthalene mothballs 1
• Treat all infected family members simultaneously 1

Comparative Efficacy

The 2014 British Association of Dermatologists guidelines indicate that terbinafine is generally preferred over itraconazole for dermatophyte onychomycosis 1, with recent research showing that continuous dosing of terbinafine is more effective than pulse therapy 4.

A Cochrane review found high-quality evidence that both terbinafine and azoles are more effective than placebo, with terbinafine probably being more effective than azoles for achieving clinical and mycological cure 5.

The most common adverse effects of oral antifungals include headache, gastrointestinal symptoms, and skin rashes, but these are generally well-tolerated 1, 6.