Dosing and uses of Grifulvin V, Gris-PEG (griseofulvin)
Adult dosage forms and strengths
oral suspension, microsize
- 125mg/5mL
tablet, microsize
- 500mg (Grifulvin V)
tablet, ultramicrosize
- 125mg (Gris-PEG)
- 250mg (Gris-PEG)
Tinea Infection
Infections affecting skin, body, hair/beard, or nails
Microsize
- Tinea corporis, cruris, or capitis: 500 mg/day PO
- Tinea pedis or unguium: 1000 mg/day PO as single daily dose or divided q12hr
Ultramicrosize
- Tinea corporis, cruris, or capitis: 375 mg/day PO
- Tinea pedis or unguium: 250 mg PO q8hr
Treatment duration
- Dependent on infection site
- Tinea corporis: 2-4 weeks
- Tinea capitis: 4-6 weeks; may be up to 8-12 weeks
- Tinea pedis: 4-8 weeks
- Tinea unguium: 4-6 months
Dosing considerations
- Absorption increased with fatty meals
Pediatric dosage forms and strengths
oral suspension, microsize
- 125mg/5mL
tablet, microsize
- 500mg (Grifulvin V)
tablet, ultramicrosize
- 125mg (Gris-PEG)
- 250mg (Bris-PEG)
Tinea Infection
Infections affecting skin, body, hair/beard, or nails
<2 years old: Safety and efficacy not established
Microsize
- 11 mg/kg/day PO as single dose or divided q12hr
- 13.6-22.7 kg (30-50 lb): 125-250 mg/day
- >22.7 kg (>50 lb): 250-500 mg/day
- Off-label: 10-20 mg/kg/day PO divided q12hr
Ultramicrosize
- 7.3 mg/kg/day PO
- 13.6-22.7 kg (30-50 lb): 82.5-165 mg/day
- >22.7 kg (>50 lb): 165-330 mg/day
- Off-label: 5-15 mg/kg/day PO divided q12hr; not to exceed 750 mg/day
Treatment duration
- Dependent on infection site
- Tinea corporis: 2-4 weeks
- Tinea capitis: 4-6 weeks; may be up to 8-12 weeks
- Tinea pedis: 4-8 weeks
- Tinea unguium: 4-6 months
Dosing considerations
- Absorption increased with fatty meals
Grifulvin V, Gris-PEG (griseofulvin) adverse (side) effects
Frequency not defined
Rash (most common)
Urticaria (most common)
Headache
Fatigue
Dizziness
Insomnia
Mental confusion
Photosensitivity
Nausea
Vomiting
Epigastric distress
Diarrhea
GI bleeding
Leukopenia
Hepatotoxicity
Proteinuria
Nephrosis
Oral thrush
Angioneurotic edema (rare)
Drug-induced lupuslike syndrome (rare)
Menstrual irregularities (rare)
Paresthesia (rare)
Postmarketing Reports
Severe skin reactions (eg, Stevens-Johnson syndrome, toxic epidermal necrolysis) and erythema multiforme
Liver toxicity
Warnings
Contraindications
Hypersensitivity
Porphyria
Hepatocellular failure
Pregnancy
Cautions
Severe skin reactions (eg, Stevens-Johnson syndrome, toxic epidermal necrolysis) and erythema multiforme reported, some resulting in hospitalization or death; discontinue if severe skin reaction occurs
Elevations in AST, ALT, bilirubin, and jaundice reported, some resulting in hospitalization or death; discontinue if jaundice occurs
Patients on prolonged therapy with any potent medication should be under close observation; periodic monitoring of organ system function, including renal, hepatic and hematopoietic, should be done
Pregnancy and lactation
Pregnancy category: X; no adequate and well-controlled studies in pregnant women, but animal studies have shown embryotoxic and teratogenic effects
Lactation: Excretion in milk unknown; avoid use because of potential tumorigenicity
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Grifulvin V, Gris-PEG (griseofulvin)
Mechanism of action
Fungistatic; deposited in keratin precursor cells and is tightly bound to new keratin, and this increases resistance to fungal invasion
Absorption
Absorption of ultramicrosize griseofulvin absorption is almost complete; absorption of microsize griseofulvin is variable (25-70% of oral dose); enhanced by ingestion of fatty meal (GI absorption of ultramicrosize is 1.5 times that of microsize)
Distribution
Drug crosses placenta
Metabolism
Extensively metabolized by liver; hepatic CYP3A4 induced
Elimination
Half-life: 9-22 hr
Excretion: Urine (<1% as unchanged drug), feces, perspiration
