Diclofenac Suppository Dosing in Children
Recommended Dose
For children aged 1-12 years, the recommended dose of diclofenac suppository is 0.5 mg/kg as a single dose, with a maximum frequency of every 8 hours if repeated dosing is needed. 1
Evidence-Based Dosing Algorithm
Single Dose Administration
- Rectal suppository: 0.5 mg/kg is the evidence-based dose that achieves equivalent drug exposure (AUC) to a 50 mg adult dose 1
- This dose is lower than oral diclofenac (1 mg/kg) due to higher bioavailability of the rectal formulation (63% for suppositories vs 36% for oral suspension) 1
- The suppository route provides rapid absorption with complete systemic availability 2
Dosing Frequency
- Administer every 8 hours if repeated doses are required 3
- This 8-hourly interval is the most commonly employed dosing schedule among pediatric anesthesiologists (53% of practitioners) 3
Age and Weight Considerations
- Minimum age: 1 year - Diclofenac is licensed for children over 1 year of age 3
- The 0.5 mg/kg dose produces consistent drug exposure across the 1-12 year age range without need for age-specific adjustments 1, 4
- Allometric size models adequately predict clearance and volume of distribution changes with age, supporting weight-based dosing 4
Clinical Context and Effectiveness
Antipyretic Use
- Rectal diclofenac 1 mg/kg demonstrates superior fever reduction compared to paracetamol 15 mg/kg in the first hour (temperature reduction 1.73°C vs 0.65°C, P < 0.001) 5
- Note: The antipyretic study used 1 mg/kg, but for analgesic purposes in surgical pain, 0.5 mg/kg suppository is the pharmacokinetically validated dose 1
Perioperative Analgesia
- Diclofenac suppositories are widely used intraoperatively (78% of pediatric anesthesiologists) and provide effective opioid-sparing analgesia 3
- The rectal route (80% usage) is preferred intraoperatively when oral administration is not feasible 3
Critical Safety Considerations
- Avoid in adenotonsillectomy: Only 57% of practitioners use NSAIDs for this procedure due to bleeding risk concerns 3
- Contraindicated in active bleeding disorders or when hemostasis is critical
- Renal function monitoring may be needed with repeated dosing, as conjugate metabolites are renally excreted 2
- No dosage adjustment needed for routine pediatric use, as clearance scales appropriately with body size 2
Common Pitfall to Avoid
Do not use the oral dose (1 mg/kg) for rectal administration - this would result in 75% higher drug exposure than intended due to the higher bioavailability of suppositories (63% vs 36%) 1. The correct suppository dose is 0.5 mg/kg, not 1 mg/kg.