Recommended Pediatric Dose of Salbutamol Plus Guaifenesin Syrup
For combination salbutamol-guaifenesin syrup in pediatric patients, dose each component separately based on weight and age: salbutamol 0.1-0.15 mg/kg per dose (maximum 2-4 mg) every 6-8 hours, and guaifenesin 100-400 mg per dose based on age, every 4-6 hours as needed.
Salbutamol Dosing Component
Oral Syrup Dosing by Weight/Age
- Children under 20 kg (typically <6 years): 0.1 mg/kg per dose, typically 1-2 mg every 6-8 hours 1, 2
- Children over 20 kg (typically ≥6 years): 2-4 mg per dose every 6-8 hours 1, 3
- Maximum single dose: 4 mg per dose 3
Safety Considerations for Salbutamol
- Oral salbutamol syrup at 1-2 mg every 8 hours has been demonstrated safe in children aged 2-6 years, with minimal side effects at these doses 3
- Monitor for tachycardia, tremors, and hypokalemia with repeated dosing 1, 2
- Always assess heart rate, respiratory rate, and oxygen saturation when administering salbutamol 1, 2
Guaifenesin Dosing Component
Age-Based Dosing
- Children 2-5 years: 100 mg per dose every 4-6 hours 4
- Children 6-11 years: 200 mg per dose every 4-6 hours 4
- Adolescents 12-17 years: 200-400 mg per dose every 4-6 hours 4
Pharmacokinetic Considerations
- Guaifenesin clearance and volume of distribution increase with age due to body size changes, but no maturation-related changes occur beyond age 2 years 4
- Systemic exposure remains similar when comparing upper pediatric doses (6-11 years) with lower adolescent doses (12-17 years) 4
Critical Dosing Principles
Avoid Simple Weight-Based Scaling
- Do not simply scale adult doses down by weight alone - this results in underdosing in children over 2 years (who are metabolically mature but smaller) and overdosing in neonates/infants (who have immature elimination pathways) 5
- Children ≥2 years are essentially metabolically mature adults who differ only in size, while neonates and infants require special consideration for immature drug elimination 5
Administration Timing
- Administer guaifenesin with food or 2 hours after meals to optimize absorption 4
- Space salbutamol doses at least 6-8 hours apart to minimize cardiovascular side effects 3
Common Pitfalls to Avoid
- Overdosing salbutamol: Can lead to significant tachycardia, tremors, and hypokalemia requiring dose reduction 1
- Underdosing in older children: Using infant doses in school-age children results in inadequate bronchodilation 1, 5
- Ignoring age-specific formulations: Many combination products lack pediatric-specific dosing guidelines, requiring individual component calculation 6