Guaifenesin Dosing for a 6-Year-Old Child Weighing 21 kg
For a 6-year-old child weighing 21 kg, administer guaifenesin 5 to 10 mL (100 to 200 mg) every 4 hours, not exceeding 6 doses in 24 hours. 1
Specific Dosing Parameters
- Dose range: 5 to 10 mL (equivalent to 1 to 2 teaspoonfuls) per dose 1
- Dosing interval: Every 4 hours 1
- Maximum frequency: Do not exceed 6 doses in any 24-hour period 1
- Standard concentration: Guaifenesin oral solution is typically 100 mg/5 mL 1
Practical Dosing Approach
Start with 5 mL (100 mg) every 4 hours and titrate upward to 10 mL (200 mg) every 4 hours if symptom control is inadequate. 1, 2 The flexible dosing range allows for dose titration to increase plasma concentrations as needed for therapeutic effect. 2
Important Clinical Considerations
- Rounding tolerance: Guaifenesin can be rounded by up to 15% for ease of home administration, making practical dosing more convenient for caregivers. 3
- Multiple daily doses required: Immediate-release guaifenesin has a short half-life, necessitating dosing every 4 hours to maintain therapeutic efficacy throughout the day. 4, 2
- Mechanism of action: Guaifenesin works by stimulating the gastrointestinal tract rather than through systemic absorption, which is why oral administration is essential for expectorant action. 5
Common Pitfalls to Avoid
- Do not exceed 6 doses in 24 hours: This translates to a maximum daily dose of 60 mL (1,200 mg) for this child, even if symptoms persist. 1
- Verify the formulation concentration: Ensure caregivers understand the concentration of the specific product being dispensed, as concentrations may vary between brands. 1
- Avoid combination products without accounting for total dose: If using guaifenesin-containing combination products (with dextromethorphan or other agents), ensure the guaifenesin component does not exceed the maximum daily limit. 3, 1