Terbutaline Dosage for Pediatric Patients in Oral Syrup Formulation
The recommended dose of terbutaline in pediatric patients for oral syrup containing terbutaline, guaiphenesin, and bromhexine is 0.05-0.15 mg/kg/dose administered 3 times daily. 1
Dosing Guidelines
Oral Terbutaline Dosing
- Standard dose range: 0.05-0.15 mg/kg/dose administered 3 times daily
- Maximum daily dose: Should not exceed 0.3-0.45 mg/kg/day
- Age-based considerations:
- Children <12 years: 0.05-0.15 mg/kg/dose TID
- Children ≥12 years: Adult dosing may be appropriate (2.5-5 mg TID)
Administration Considerations
- Oral terbutaline has a slower onset of action compared to inhaled or parenteral routes
- Peak effect occurs within 1-2 hours after oral administration
- Duration of action is approximately 4-6 hours, supporting TID dosing
- The combination with guaiphenesin (expectorant) and bromhexine (mucolytic) is intended to address both bronchospasm and mucus production
Clinical Evidence and Recommendations
The British Thoracic Society guidelines indicate that terbutaline can be effectively used in pediatric patients with asthma 1. While the guidelines focus more on nebulized and inhaled formulations, they provide dosing information that can be extrapolated to oral preparations.
Research by The New Zealand Medical Journal demonstrated that terbutaline produces significant bronchodilation in children with asthma, with effectiveness demonstrated even at lower doses 2. This supports the conservative approach to oral dosing, starting at the lower end of the recommended range.
Monitoring and Safety Considerations
Monitor for common side effects:
- Tachycardia
- Tremor
- Nervousness
- Headache
- Potential hypokalemia with prolonged use
Important cautions:
- Start at the lower end of the dosing range and titrate based on clinical response
- Use with caution in patients with cardiac conditions, hypertension, or hyperthyroidism
- Monitor heart rate in patients receiving higher doses
- Consider checking potassium levels in patients on prolonged therapy
Special Considerations
- For acute severe asthma, oral terbutaline is not the preferred route of administration; inhaled or nebulized routes provide faster onset of action 1
- In children who cannot use inhalers effectively, oral therapy may serve as an alternative maintenance option
- The combination with guaiphenesin and bromhexine may be particularly useful in patients with productive cough or thick secretions
Alternative Routes of Administration (if oral route inadequate)
- Nebulized terbutaline: 0.1-0.3 mg/kg/dose (maximum 10 mg) every 20 minutes for acute symptoms 1
- MDI with spacer: 250 μg per actuation, with dosing similar to other beta-agonists 1
- Subcutaneous: 0.01 mg/kg (maximum 0.25 mg) for emergency situations 1
Remember that oral formulations are generally reserved for maintenance therapy rather than acute symptom relief due to their slower onset of action compared to inhaled formulations.