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Antifungal — Tinea Capitis Pregnancy: No evidence of safety in human pregnancy; teratogenic in animals and case reports of human foetal abnormalities. Must not be used in pregnancy or become pregnant within one month of stopping; males should not father children within six months of treatment. Excretion in human milk unknown.

Griseofulvin

Brand names: Grisovin

Griseofulvin is an oral antifungal used for dermatophyte infections of the skin, hair and nails, particularly tinea capitis where topical therapy is ineffective.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 500 to 1000 mg daily (but not less than 10 mg/kg bodyweight daily)
Route: Oral
Frequency: A single dose daily is often satisfactory, but divided doses may be more effective in patients who respond poorly
Dermatology context: systemic treatment of dermatophyte (ringworm) infections of skin, hair and nails. Duration depends on thickness of keratin at the site of infection: for hair or skin at least four weeks; toe or fingernails may need six to twelve months. Therapy should be continued for at least two weeks after all signs of infection have disappeared. Doses should be taken after meals, otherwise absorption is likely to be inadequate. Should not be used prophylactically.

Paediatric dose

Dose: 10 mg/kg
Route: Oral
Frequency: Daily in divided doses
eMC (UK SPC) paediatric population: usually 10 mg/kg (5 mg/lb) body weight daily in divided doses. Doses should be taken after meals. Duration as for adults (skin/hair at least four weeks; nails six to twelve months; continue at least two weeks after signs of infection disappear).

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Paediatric weight-based calculator

eMC (UK SPC) paediatric population: usually 10 mg/kg (5 mg/lb) body weight daily in divided doses. Doses should be taken after meals. Duration as for adults (skin/hair at least four weeks; nails six to twelve months; continue at least two weeks after signs of infection disappear).

Verify in a children's formulary

Contraindications

  • Porphyria or severe liver disease
  • Systemic Lupus Erythematosus (griseofulvin has been reported to exacerbate the condition)
  • Hypersensitivity to the active substance or to any of the excipients
  • Pregnancy, or women intending to become pregnant within one month of stopping treatment; males should not father children within six months of treatment

Side effects

  • Diarrhoea, nausea and vomiting (common)
  • Headache and gastric discomfort
  • Urticarial reactions, skin rashes; photosensitivity reactions
  • CNS effects e.g. confusion, dizziness, impaired coordination, peripheral neuropathy; drowsiness
  • Rare: toxic epidermal necrolysis, erythema multiforme, significant LFT elevations, leucopenia with neutropenia, precipitation of SLE

Interactions

  • Oral contraceptives: reduced blood level/efficacy — additional contraceptive precautions needed during treatment and for a month after stopping
  • Coumarin anticoagulants: reduced efficacy — monitor and adjust dose
  • Cyclosporin: reduced blood level/efficacy
  • Phenobarbitone: inhibits absorption of griseofulvin; phenylbutazone and sedative/hypnotic enzyme-inducing drugs may impair griseofulvin efficacy
  • Alcohol: enhancement of the effects of alcohol has been reported

Clinical monograph

How it works

It binds fungal microtubules and disrupts mitotic spindle function, and is deposited in keratin precursor cells, rendering newly formed keratin resistant to dermatophyte invasion.

Prescribing in practice

  • It is contraindicated in pregnancy and in severe liver disease; effective contraception is needed during and for a period after treatment, and men should avoid fathering a child during and shortly after the course.
  • It induces hepatic enzymes and can reduce the efficacy of combined hormonal contraceptives and interact with warfarin and ciclosporin.
  • Prolonged courses are usually required, as growth of healthy keratin must replace the infected tissue.

Monitoring

For long courses, monitor liver function and full blood count, and confirm mycological cure rather than relying on appearance alone.

Counselling the patient

  • Take with or after food, ideally a fatty meal, to aid absorption.
  • Avoid alcohol, which can cause flushing, and report any yellowing of the skin or eyes.
  • Use reliable additional contraception as this medicine can make the pill less effective.

Evidence & guidelines

Oral antifungals including griseofulvin are recommended for tinea capitis, as topical agents do not reliably eradicate scalp infection.

Reference: BAD Tinea Capitis Guidelines 2014; PHE Guidance on Tinea Capitis in Schools; NICE CKS Ringworm; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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