Griseofulvin Dosage for Pediatric Ringworm (Tinea Corporis)
For pediatric patients with ringworm (tinea corporis), the recommended dosage of griseofulvin is 10-20 mg/kg/day for 2-4 weeks. 1
Dosage Guidelines
Griseofulvin is the only FDA-approved antifungal medication for tinea infections in children under 12 years in the UK. The appropriate dosage depends on the child's weight and the specific formulation:
- Standard dosage: 10 mg/kg daily 1
- For children 30-50 lbs (13.6-22.7 kg): 125-250 mg daily
- For children over 50 lbs (22.7 kg): 250-500 mg daily, in divided doses 1
- Treatment duration for tinea corporis: 2-4 weeks 1
Administration Recommendations
- Administer with fatty food to increase absorption and improve bioavailability 2
- The medication can be given as a single daily dose or divided throughout the day 1
- Continue treatment until the infecting organism is completely eradicated as confirmed by appropriate clinical or laboratory examination 1
Efficacy Considerations
The effectiveness of griseofulvin varies depending on the causative organism:
- More effective for Microsporum species (88.5% response rate) 2
- Less effective for Trichophyton species (67.9% response rate) 2
- For Trichophyton infections, higher doses for longer periods (12-18 weeks) may be required 2
Monitoring and Follow-up
- Clinical improvement should be expected within 1-2 weeks of starting treatment 3
- Treatment should continue for at least one week after clinical resolution 3
- The endpoint of treatment should be mycological cure, not just clinical improvement 3
- Consider follow-up mycological examination in resistant or recurrent cases 3
Safety Profile
- Generally well-tolerated in children
- Side effects include gastrointestinal disturbances and rashes in <8% of patients 2
- Contraindicated in lupus erythematosus, porphyria, and severe liver disease 2
Important Considerations
- Topical therapy alone is not recommended for ringworm management, but can be used as an adjunct to reduce transmission 2
- General hygiene measures should be observed to control sources of infection or reinfection 1
- For extensive or resistant infections, consider alternative agents such as terbinafine (for Trichophyton species) or itraconazole 3
- Screening and treating family members may be necessary to prevent reinfection, particularly with anthropophilic species 2, 3
Treatment Failure
If treatment fails, consider:
- Poor compliance
- Suboptimal absorption
- Relative insensitivity of the organism
- Reinfection 3
In such cases, consider: