What is the recommended duration of antifungal treatment for onychomycosis, and how should I monitor treatment response?

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Posted: 16 August 2025Updated: 16 August 2025 Guideline-Aligned (High Confidence) Clinically Reviewed
Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX

Recommended Duration of Antifungal Treatment for Onychomycosis:

  • Topical antifungal treatment with amorolfine 5% nail lacquer should be applied once or twice weekly for 6 months for fingernails and 9–12 months for toenails.
  • Oral terbinafine is prescribed at 250 mg once daily for 6–12 weeks for fingernail infections and 12–24 weeks for toenail infections.
  • Oral itraconazole is given as pulsed therapy: 200 mg twice daily for 1 week, repeated after 21 days; two pulses for fingernail infections and three pulses for toenail infections.

Monitoring Treatment Response:

  • Monitor nail growth 3–6 months after starting treatment, as this is the time needed for healthy nail outgrowth and optimal clinical effect.
  • Consider filing a notch at the base of the most abnormal nail at treatment start to help compare old and new nail growth.
  • Use serial photographs (e.g., mobile phone photos) to document nail growth progress.
  • If abnormal nail remains distal to the notch as it grows out, no further treatment is needed; if abnormal nail moves proximal to the notch, ongoing infection is indicated and further treatment is required.
  • If normal nail regrowth does not occur, consider re-sampling for fungal culture, managing underlying causes, or combination topical and oral antifungal treatment.

These recommendations apply to adults; oral antifungals are not licensed for children and treatment in children is generally not advised in primary care.

Patient expectations should be managed as onychomycosis is difficult to eradicate and often recurs.

References:

Educational content only. Always verify information and use clinical judgement.