Dermatophyte: Fingernails and Toenails

Doses are oral and for adults unless otherwise stated. Visit the Health Products Regulatory Board website or the printed Irish Medicines Formulary for drug SPCs, dosage, contraindications, interactions, or IMF/BNF/BNFC/MIMS. See guidance on dosing in children for quick reference dosage/weight guide.

Letters indicate strength of evidence range from A+ (systematic review) to D (informal opinion). Statins can interact with some antibiotics and increase the risk of rhabdomyolysis. Amiodarone and drugs which prolong the QT interval can interact with many antibiotics. Many antibiotics increase the risk of bleeding with anticoagulants. Please refer to our Drug Interactions Table for further information.

Comments from Expert Advisory Committee

  • Take nail clippings: Start therapy if infection is confirmed by laboratory.
  • Idiosyncratic liver reactions occur rarely with terbinafine. It is more effective than the azoles.
  • Itraconazole is also active against yeasts.
  • In non-dermatophyte moulds use itraconazole.C
  • For children seek specialist opinion




TX Duration

5% amorolfine nail lacquer B- (for superficial)


fingers 6 months toes 12 months


250 mg OD

fingers 6 – 12 weeks toes 3 – 6 months

second line: itraconazole 200 mg BD fingers 7 days monthly
(2 courses) toes 7 days monthly (3 courses)
  • Onychomycosis commoner in toenails than nails.
  • Baseline LFT's. Antifungals are associated with hepatoxicity rarely (idiosyncratic). Risk benefit discussion with the patient as cure rates range between only 20-50%
  • Take nail clippings and subungal debris for microscopy and culture. Exclude other nail disease.
  • 1st line : Terbenafine (preferred over Itraconazole) 250mgs od po 6/52 fingernails.
  • 12-16 weeks for toenails.
  • 1st line : Itraconazole 200mgs od po 12 weeks or a pulse dose 400mgs per day for one week per month. 2 pulses for fingernails and 3 pulse weeks for toenails.
  • 2nd line : Fluconazole 150-450mgs/week 3/12 fingernails and 6/12 toenails.
  • Griseofulvin: 500-1000mgs/day 6-9 months fingernails and 12-18months in toenails.
  • Amorolfine: 5% lacquer once or twice weekly for 6/12.


  • Ameen M et al.BAD guidelines for onychomycosis. BJD 2014;171: 937–958.
  • Shemer A. Update : medical treatment of onychomycosis. Invited article. Dermatological therapy. 2012;25:582-593.

Reviewed June 2016