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Griseofulvin

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Griseofulvin, Gris-Peg

  • See also
  1. Antifungal Medication
  2. Topical Antifungal
  3. Tinea Capitis
  • Indications
  1. Tinea Capitis
  2. Other indications (other Antifungals are preferred)
    1. Tinea Corporis
    2. Tinea Pedis
    3. Onychomycosis
  • Contraindications
  1. Hepatic Failure
  2. Porphyria
  • Mechanism
  1. Antifungal derived first in 1958 from the mold Penicillium griseofulvum
  2. Inhibits fungal cell division by inhibiting microtubule function in Mitosis
    1. Binds tubulin in fungi and disrupts mitotic spindles
  3. Griseofulvin is fungistatic (NOT fungicidal)
    1. It suppresses fungal growth, but does not kill fungal organisms
  4. Griseofulvin deposits in keratin precursor cells of the skin, hair and nails
    1. As superficial, keratinized skin cells slough
    2. Griseofulvin infused cells gradually rise to the surface, slowly eliminating the infection
  • Medications
  1. Griseofulvin Microsize
    1. Tablets: 500 mg
    2. Suspension: 125 mg/5 ml
  2. Griseofulvin Ultramicrosize
    1. Tablets: 125 mg, 250 mg
  1. General
    1. Take with food (especially a fatty meal) for better absorption
  2. Griseofulvin microsize (Griseofulvin V)
    1. Adult: 500 mg (up to 1 g) orally daily
    2. Child: 20 to 25 mg/kg/day (max 1000 mg/day, AAP dosing) orally daily until Hair Growth
  3. Griseofulvin Ultramicrosize (more expensive, but may have better absorption)
    1. Adult: 375 mg orally once daily (up to twice daily)
    2. Child: 10 to 15 mg/kg orally daily (max 750 mg/day, AAP off-label dosing)
  4. Duration
    1. Tinea Capitis: 4 to 6 weeks (up to 8 week) or 2 weeks after cultures are negative
    2. Other indication durations are listed, but other agents are preferred
      1. Tinea Corporis: 2 to 4 weeks
      2. Tinea Pedis: 4 to 8 weeks
      3. Fingernail Onychomycosis: 4 months
      4. Toenail Onychomycosis: 6 months
  • Adverse Effects
  1. Photosensitivity
  2. Drug-induced Lupus (or exacerbation of pre-existing Systemic Lupus Erythematosus)
  3. Other uncommon adverse effects
    1. Headache
    2. Nausea or Vomiting
    3. Bone Marrow suppression (Leukopenia)
  • Safety
  1. Avoid in pregnancy (Teratogenic)
  2. Unknown safety in Lactation
  • Drug Interactions
  1. Warfarin
    1. Decreases INR
  2. Oral Contraceptives
    1. Decreases efficacy (use reliable Contraception)
  • Efficacy
  1. Very effective for Tinea Capitis with >2 months of use
  2. Not as effective for Tinea Unguium (Onychomycosis)
  • Monitoring
  1. No baseline testing needed in the absence of liver disease
  2. Obtain labs for treatment duration >8 weeks (or history of abnormal Liver Function Tests)
    1. Liver Function Tests (ALT, AST, Serum Bilirubin) every 8 weeks
    2. Complete Blood Count (CBC) every 8 weeks
    3. Serum Creatinine every 8 weeks
  • Resources
  1. Griseofulvin Tablets (DailyMed)
    1. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=98829d90-b289-4bec-a625-7af412a5cb2d
  • References
  1. Ely (2014) Am Fam Physician 90(10): 702-10 [PubMed]