What are the treatment options for onychomycosis (toenail fungus)?

Treatment Options for Onychomycosis (Toenail Fungus)

Oral terbinafine is the first-line treatment for toenail fungus (onychomycosis) due to its superior efficacy compared to other treatments, with cure rates of 70-80% for toenail infections. 1

Diagnosis Before Treatment

• Proper diagnosis through laboratory testing (KOH preparation, fungal culture, or nail biopsy) should be obtained before initiating treatment, as incorrect diagnosis is the most common cause of treatment failure 1
• Dermatophytes are the most common causative organisms in onychomycosis 1

Treatment Algorithm

First-line Treatment:

• Oral terbinafine: 250 mg daily for 12 weeks for toenail infections 2, 1
  • Highest cure rates (70-80%) for toenail infections 1
  • Fungicidal action with very low minimum inhibitory concentration 1
  • Superior to itraconazole both in vitro and in vivo for dermatophyte onychomycosis 1

Alternative Oral Treatments:

• Oral itraconazole: 200 mg daily for 12 weeks continuously, or as "pulse therapy" at 400 mg daily for 1 week per month for 3 months 1
  • Second-line option if terbinafine is contraindicated 1
  • Less effective than terbinafine for dermatophyte infections 1

Topical Treatments (for mild cases only):

• Ciclopirox 8% nail lacquer: Applied daily as part of a comprehensive management program that includes monthly removal of unattached, infected nails 3
• Only appropriate for very distal infection or superficial white onychomycosis (SWO) 1
• Significantly lower success rates compared to oral therapy 1

Special Considerations

Contraindications and Monitoring

• Terbinafine:

  • Contraindicated in patients with history of allergic reaction 2
  • Liver function tests should be performed before treatment and monitored periodically 2
  • Watch for hepatotoxicity, taste disturbance, smell disturbance, and depressive symptoms 2

• Itraconazole:

  • Use caution in patients with heart failure or liver disease 1
  • Significant drug interactions with many medications 1

Treatment Failure Management

• If treatment fails despite proper compliance, consider:
  • Presence of subungual dermatophytoma (dense white lesion beneath the nail) 1
  • Partial nail removal may be necessary for dermatophytomas or thick nails (>2mm) 1
  • Alternative drug or nail removal in combination with further antifungal therapy 1

Preventing Recurrence

• Recurrence rates are high (40-70%) after successful treatment 1
• Preventive measures include:
  • Wearing protective footwear in public bathing facilities, gyms, and hotel rooms 1
  • Using antifungal powders containing miconazole, clotrimazole, or tolnaftate in shoes 1
  • Keeping nails short and avoiding sharing nail clippers 1
  • Consider discarding contaminated footwear or treating with naphthalene mothballs in a sealed plastic bag for 3 days 1

Emerging Treatments

• Laser therapy: Near infrared diode and neodymium-doped yttrium aluminum garnet lasers show promising results but insufficient evidence for recommendation 1
• Photodynamic therapy: Limited evidence with cure rates of 36-44%, not currently recommended 1

Treatment Outcomes

• Even with optimal treatment, complete clinical cure rates are often below 50%, though mycological cure rates are about 30% better 1
• Patient satisfaction typically correlates with mycological cure rather than perfect clinical appearance 1
• Treatment should be considered not just for cosmetic reasons but also to prevent complications such as cellulitis in elderly or diabetic patients 1

Remember that onychomycosis is a chronic infection that requires patience and persistence for successful treatment, as complete nail regrowth can take up to 18 months due to the slow growth pattern of toenails 1.