Comparative Pharmacology
Head-to-head clinical analysis: MAXAIR versus SOMOPHYLLIN T.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MAXAIR versus SOMOPHYLLIN T.
MAXAIR vs SOMOPHYLLIN-T
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Beta-2 adrenergic receptor agonist; relaxes bronchial smooth muscle via increased intracellular cAMP.
Theophylline is a methylxanthine that inhibits phosphodiesterase, leading to increased intracellular cAMP levels, causing bronchodilation, and also acts as an adenosine receptor antagonist.
2 inhalations (340 mcg) via oral inhalation every 4-6 hours as needed for bronchospasm; not to exceed 12 inhalations per day.
Oral: 200-400 mg twice daily (12-hourly). Dose titration: start 200 mg twice daily, increase by 200 mg/day every 3 days as tolerated to achieve serum theophylline level 5-15 mcg/mL. Maximum: 800 mg/day or 400 mg twice daily.
None Documented
None Documented
3.5–4.0 hours; clinically, this supports dosing every 4–6 hours as needed.
Terminal elimination half-life is approximately 8 hours in healthy adults (range 3-13 hours). In neonates, it is prolonged (20-30 h). In smokers, half-life is reduced to 4-5 h. In patients with hepatic cirrhosis or heart failure, half-life may exceed 24 hours.
Renal excretion of unchanged drug accounts for approximately 90% of elimination; fecal excretion is minimal (<5%).
Approximately 90% is eliminated via hepatic metabolism (primarily via CYP1A2, CYP3A4), and about 10% is excreted unchanged in the urine. Renal clearance accounts for <10% of total clearance in adults. Biliary/fecal excretion is minimal (less than 5%).
Category C
Category C
Bronchodilator
Bronchodilator