Comparative Pharmacology
Head-to-head clinical analysis: MAXAIR versus THEOPHYL 225.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MAXAIR versus THEOPHYL 225.
MAXAIR vs THEOPHYL-225
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, and antagonizes adenosine receptors (A1, A2). This results in bronchodilation, reduced airway inflammation, and enhanced diaphragmatic contractility.
2 inhalations (340 mcg) via oral inhalation every 4-6 hours as needed for bronchospasm; not to exceed 12 inhalations per day.
225 mg orally every 6 hours; adjust based on serum theophylline levels to maintain therapeutic range 10-20 mcg/mL.
None Documented
None Documented
3.5–4.0 hours; clinically, this supports dosing every 4–6 hours as needed.
Terminal half-life: 3–12 hours (adults); shorter (1–5 hours) in children and smokers; prolonged in hepatic cirrhosis, heart failure, or elderly. Steady-state achieved in 1–2 days.
Renal excretion of unchanged drug accounts for approximately 90% of elimination; fecal excretion is minimal (<5%).
Renal: 10% unchanged; hepatic metabolism (CYP1A2, CYP3A4) accounts for ~90% of elimination, with metabolites (e.g., 3-methylxanthine, 1,3-dimethyluric acid) excreted renally.
Category C
Category C
Bronchodilator
Bronchodilator