Mefenamic Acid Pediatric Dosing for Fever
The recommended dose of mefenamic acid for pediatric fever is 6 mg/kg per dose, given orally every 6-8 hours, though acetaminophen (15 mg/kg) or ibuprofen (10 mg/kg) should be used as first-line antipyretics instead. 1
Primary Recommendation: Use Acetaminophen or Ibuprofen First
- Acetaminophen remains the preferred first-line antipyretic at 10-15 mg/kg per dose every 4-6 hours (maximum 60 mg/kg/day), particularly for infants under 6 months. 2
- Ibuprofen is recommended at 10 mg/kg per dose every 6-8 hours for children ≥6 months of age. 2
- NSAIDs like mefenamic acid should be reserved for pain management or chronic inflammatory conditions rather than simple fever control due to safety considerations. 1
Mefenamic Acid Dosing When Used
Standard Dosing
- The established pediatric dose is 6 mg/kg per dose, administered orally. 1
- Dosing interval follows typical NSAID patterns of every 6-8 hours, similar to ibuprofen. 2
Evidence Supporting This Dose
- A 2022 randomized controlled trial demonstrated that mefenamic acid 6 mg/kg had comparable antipyretic efficacy to high-dose paracetamol (20 mg/kg), with mean time to normal temperature of 84.90±30.42 minutes. 1
- Older studies from 1977-1978 suggested 4 mg/kg as the optimal antipyretic dose, though the more recent trial used 6 mg/kg with good safety profile. 3, 4
Clinical Context and Limitations
Why Mefenamic Acid Is Not First-Line
- The American Academy of Pediatrics guidelines for pediatric fever management do not include mefenamic acid in their recommended antipyretic agents. 2
- Standard guidelines emphasize acetaminophen and ibuprofen as the evidence-based antipyretics with established safety profiles in children. 2
- The 2022 trial concluded that "mefenamic acid may be avoided as an antipyretic and spared for pain and anti-inflammatory indications." 1
When Mefenamic Acid Might Be Considered
- Geographic regions where this medication is commonly available and approved for pediatric use. 1
- Situations where both pain control and fever reduction are needed simultaneously.
- Cases where acetaminophen and ibuprofen are contraindicated or unavailable.
Age-Specific Considerations
Infants Under 6 Months
- Acetaminophen is the only recommended antipyretic, with ibuprofen generally not recommended for this age group. 2
- Mefenamic acid has even less safety data in young infants and should be avoided.
Children 6 Months and Older
- Both acetaminophen and ibuprofen are appropriate first-line options. 2
- If mefenamic acid is used, the 6 mg/kg dose applies across pediatric age ranges based on available evidence. 1
Safety and Monitoring
Adverse Effects
- The 2022 trial reported negligible adverse effects with mefenamic acid 6 mg/kg, though the sample size was limited (n=159). 1
- As with all NSAIDs, monitor for gastrointestinal symptoms, renal function concerns, and bleeding risk.
Duration of Action
- Mefenamic acid showed a trend toward longer duration before next fever spike (8.82±3.83 hours) compared to standard-dose paracetamol (5.07±2.66 hours), though this was not statistically significant. 1
Common Pitfalls to Avoid
- Do not use mefenamic acid as routine first-line therapy for simple fever—reserve it for specific indications. 1
- Do not exceed recommended NSAID dosing intervals; maintain at least 6-8 hours between doses.
- Avoid NSAIDs in children with dehydration, renal impairment, or bleeding disorders.
- Do not use in infants under 6 months of age where safety data is lacking.