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Allylamine antifungal

Terbinafine

Brand names: Lamisil

Adult dose

Dose: Onychomycosis: 250mg PO OD x6 weeks (fingernails) or 12 weeks (toenails). Tinea: 250mg OD x2-6 weeks
Route: PO/Topical
Frequency: OD

Dose adjustments

Renal

Reduce if eGFR <50

Clinical pearls

  • Dermatophyte onychomycosis (1st-line)
  • Confirm with mycology; check LFTs baseline + 4–6 weeks

Contraindications

  • Severe hepatic impairment
  • Active liver disease
  • Hypersensitivity

Side effects

  • Hepatotoxicity (boxed)
  • Taste disturbance
  • Cytopenias
  • Severe skin reactions (SJS/TEN, DRESS)
  • SLE-like syndrome

Interactions

  • CYP2D6 substrates
  • Warfarin
  • Caffeine

Monitoring

  • LFTs
  • FBC

Reference: BNF; NICE CKS; MHRA; https://bnf.nice.org.uk/drugs/terbinafine/. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

Pathways