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Antifungal — Tinea Capitis Pregnancy: CONTRAINDICATED — teratogenic; must use effective contraception during and for 1 month after treatment

Griseofulvin

Brand names: Grisovin

Adult dose

Dose: 500 mg once daily (or 250 mg twice daily) for 6–8 weeks (tinea capitis); up to 1 g/day for severe infections
Route: Oral (take with fatty meal — enhanced absorption)
Frequency: Once or twice daily
Max: 1 g/day
Systemic antifungal for tinea capitis (scalp ringworm) — particularly effective for Microsporum canis infections where terbinafine is less effective. Also used for tinea corporis, tinea pedis, and onychomycosis when other agents fail or are contraindicated.

Paediatric dose

Dose: 10 mg/kg/day (or 10–20 mg/kg/day for fine-particle preparation) mg/kg
Route: Oral (with fatty food or full-fat milk)
Frequency: Once or twice daily
Max: 500 mg/day
BNFc: tinea capitis — 10 mg/kg once daily for 6–12 weeks; Microsporum canis may require longer (12–16 weeks). Suspension not licensed — tablets can be crushed and given with fatty food.

Dose adjustments

Renal

No dose adjustment required

Hepatic

Avoid in significant hepatic impairment

Paediatric weight-based calculator

BNFc: tinea capitis — 10 mg/kg once daily for 6–12 weeks; Microsporum canis may require longer (12–16 weeks). Suspension not licensed — tablets can be crushed and given with fatty food.

Clinical pearls

  • First-line for Microsporum canis tinea capitis — terbinafine has inferior efficacy against Microsporum species; species identification (culture + PCR) guides treatment choice
  • Trichophyton species (T. tonsurans, T. violaceum): terbinafine preferred; Microsporum species: griseofulvin preferred
  • Must be taken with fatty food — lipophilic drug requiring fat for absorption; full-fat milk is ideal vehicle for children
  • Contraception: OCP efficacy reduced — additional barrier contraception required; pregnancy must be excluded before initiating and for 1 month after
  • School exclusion in tinea capitis: UK guidance (PHE/BAD) — children do NOT need to be excluded from school; can return once treatment started; share shampoo and combs are main transmission vectors
  • Selenium sulfide or ketoconazole shampoo: adjunct to systemic treatment — reduces contagion by killing surface spores

Contraindications

  • Pregnancy — CONTRAINDICATED and for 1 month after stopping (teratogenic)
  • Severe hepatic impairment
  • Porphyria (precipitates acute attack)
  • Systemic lupus erythematosus (may exacerbate)
  • Hypersensitivity to griseofulvin

Side effects

  • Headache (most common)
  • GI disturbance
  • Photosensitivity
  • Skin rash (including SJS/TEN rare)
  • Hepatotoxicity
  • Leucopenia (prolonged use)
  • Peripheral neuropathy (prolonged use)
  • Lupus-like reactions

Interactions

  • Warfarin — reduces anticoagulant effect (induces CYP enzymes; monitor INR)
  • OCP — reduces efficacy (enzyme induction; additional contraception required)
  • Ciclosporin — reduces ciclosporin levels
  • Alcohol — flushing reaction

Monitoring

  • FBC and LFTs (baseline; monthly for prolonged courses)
  • Treatment response (scale/hair loss improvement at 4–6 weeks)
  • Mycological cure (post-treatment culture)

Reference: BNFc; BNF 90; BNFc; BAD Tinea Capitis Guidelines 2014; PHE Guidance on Tinea Capitis in Schools; NICE CKS Ringworm. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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