What are the treatment options for onychomycosis?

Treatment of Onychomycosis

Oral terbinafine is the first-line treatment for onychomycosis due to its superior efficacy compared to other antifungal agents, with cure rates of 70-80% for toenail infections and 80-90% for fingernail infections. 1

Diagnosis Confirmation

Before initiating treatment:

• Obtain appropriate nail specimens for laboratory testing (KOH preparation, fungal culture, or nail biopsy) to confirm diagnosis 2
• Identify causative organism (dermatophytes, Candida, or non-dermatophyte molds)

Treatment Algorithm

First-line Treatment for Dermatophyte Onychomycosis

Oral Therapy

• Terbinafine (strength of recommendation A; level of evidence 1+) 1
  • Adults: 250 mg daily for 6 weeks (fingernails) or 12 weeks (toenails)
  • Children:
    • <20 kg: 62.5 mg daily
    • 20-40 kg: 125 mg daily

    • 40 kg: 250 mg daily

    • Duration: 6 weeks (fingernails) or 12 weeks (toenails) 3
  • Monitor: Baseline liver function tests and complete blood count

Alternative Oral Therapy

• Itraconazole (if terbinafine is contraindicated)

  • Adults: Pulse therapy - 200 mg twice daily for 1 week per month
    • 2 pulses for fingernails
    • 3 pulses for toenails
  • Children: 5 mg/kg/day for 1 week per month
    • 2 pulses for fingernails
    • 3 pulses for toenails 1
  • Monitor: Hepatic function tests

• Fluconazole (if terbinafine and itraconazole are contraindicated)

  • Adults: 150-450 mg once weekly for 3 months (fingernails) or 6 months (toenails)
  • Children: 3-6 mg/kg once weekly for 12-16 weeks (fingernails) or 18-26 weeks (toenails) 1

Topical Therapy (for mild cases or as adjunctive therapy)

• Amorolfine 5% lacquer (strength of recommendation D) 1

  • Apply once or twice weekly for 6-12 months
  • Most effective for superficial and distal onychomycosis

• Ciclopirox 8% lacquer (strength of recommendation C) 1, 4

  • Apply once daily for up to 24 weeks (fingernails) or 48 weeks (toenails)
  • Requires monthly removal of unattached, infected nail by healthcare professional
  • Clinical trials showed 8.5% complete cure rate vs 0% for vehicle 4

Special Considerations

Candidal Onychomycosis

• Itraconazole is the most effective agent 1
  • Same dosage as for dermatophytes: 400 mg daily for 1 week per month
  • 2 pulses for fingernail infection
  • 3-4 pulses for toenail infection

Diabetic Patients

• Terbinafine is preferred over itraconazole due to:
  • Lower risk of drug interactions
  • No risk of negative inotropic effect (itraconazole is contraindicated in congestive heart failure) 1

Children

• Higher cure rates and faster response to treatment than adults
• Check for concomitant tinea pedis and examine family members 3
• Terbinafine or itraconazole are first-line options 1

Combination Therapy

Combining oral and topical treatments may provide:

• Antimicrobial synergy
• Wider antifungal spectrum
• Improved fungicidal activity
• Increased cure rates 1

Research shows combination of oral terbinafine with ciclopirox nail lacquer achieves higher mycological cure rates (88.2%) compared to terbinafine alone (64.7%) 5

Treatment Failure Management

If treatment fails after excluding poor compliance, poor absorption, immunosuppression:

1. Consider subungual dermatophytoma preventing drug penetration
2. Partial nail removal may be indicated
3. Try alternative antifungal agent
4. Consider combination therapy 1

Prevention of Recurrence

• Treat concomitant tinea pedis
• Examine and treat family members if infected
• Consider periodic application of topical antifungals to prevent reinfection
• Avoid walking barefoot in public places
• Disinfect shoes and socks to reduce the 25% relapse rate 6

Pitfalls to Avoid

1. Treating without mycological confirmation
2. Choosing inappropriate agent based on causative organism
3. Inadequate treatment duration
4. Failing to address underlying conditions (diabetes, immunosuppression)
5. Not considering drug interactions, especially with terbinafine and medications like tricyclic antidepressants, SSRIs, beta blockers 6