Recommended Dose of Etophylline
For adults and children ≥12 years, etophylline (as theophylline extended-release) should be dosed at 400-600 mg once daily with meals, with dose titration guided by serum theophylline levels targeting 10-20 mcg/mL. 1
Standard Dosing by Age Group
Adults and Children ≥12 Years
- Initial dose: 400-600 mg once daily (morning or evening) with meals 1
- Tablets must be swallowed whole; do not chew or crush (may split scored tablets) 1
- Consistent administration with or without food is essential—if taken with food, always take with food; if fasted, always take fasted 1
Children 1-9 Years
- Average maintenance dose: 24.1 mg/kg/day (range typically 10-36 mg/kg/day) 1, 2
- Weight-adjusted dosing remains relatively constant in this age group 2
Children 9-16 Years
- Dose requirements decrease progressively with age from 24 mg/kg/day at age 9 to approximately 13 mg/kg/day by age 16 2
Adults <60 Years
- Typical range: 400-1600 mg/day to achieve therapeutic serum concentrations 1
- Most adults achieve therapeutic levels with 200-400 mg (approximately 10 mg/kg) twice daily of slow-release preparations 3
Dose Titration Strategy
Start low and titrate slowly to minimize adverse effects: 1
- Begin with sufficiently low dose for the patient's age group 1
- Increase in small increments only if previous dose is well tolerated 1
- Wait minimum 3 days between dose adjustments to allow serum concentrations to reach steady-state 1
- Discontinue if adverse effects occur, withhold until symptoms resolve, then resume at lower previously tolerated dose 1
Therapeutic Monitoring
Target Serum Concentrations
- Therapeutic range: 10-20 mcg/mL 1, 3
- Lower therapeutic range (5-10 mg/L) may be adequate for anti-inflammatory effects in chronic asthma management 4
Monitoring Frequency
- Rapidly growing children: every 6 months 1
- All other stable patients: yearly 1
- Acutely ill patients: every 24 hours 1
- Monitor after any dose adjustment once steady-state is achieved 1
Special Considerations
Dose Calculation
- Calculate mg/kg dose based on ideal body weight, as theophylline distributes poorly into body fat 1
Patients Already on Theophylline
- 68% of patients on maintenance oral theophylline already have therapeutic levels (>10 mcg/mL) when presenting with acute exacerbations 3
- Check serum level before administering additional doses to avoid toxicity 3
- Direct mg-for-mg conversion is acceptable when switching from immediate-release to extended-release formulations, though peak/trough levels may vary 1
Alternative Formulation (Etofylline)
- Standard oral dose: 50-100 mg three times daily 5
- Bioavailability approximately 80% with peak levels around 3.9 mg/L after 200 mg dose 5
- For COVID-19-associated sinus bradycardia: 150 mg once daily (etophylline/theophylline prolonged-release combination) 6
Critical Warnings
Avoid Toxicity
- At 900 mg/day in adults or 22 mg/kg/day in children ages 1-9: approximately 30% will have subtherapeutic levels (<10 mcg/mL), 50% therapeutic (10-20 mcg/mL), and 20% potentially toxic (20-30 mcg/mL) 1
- Individual clearance varies fourfold among similar patients, making population-based dosing unreliable 1
- Serum level monitoring is mandatory to individualize dosing and prevent toxicity 1