Comparative Pharmacology
Head-to-head clinical analysis: THEOLAIR SR versus THEOPHYL 225.
Peer-Reviewed Evidence
Head-to-head clinical analysis: THEOLAIR SR versus THEOPHYL 225.
THEOLAIR-SR vs THEOPHYL-225
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Theophylline is a methylxanthine that relaxes bronchial smooth muscle by inhibiting phosphodiesterase, increasing cAMP, and antagonizing adenosine receptors.
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.
Oral: 300-600 mg every 12 hours; sustained-release formulation; adjust based on serum theophylline concentrations (target 5-15 mcg/mL).
225 mg orally every 6 hours; adjust based on serum theophylline levels to maintain therapeutic range 10-20 mcg/mL.
None Documented
None Documented
Adults: 8 hours (range 5-12). Children: 3.5 hours (range 1-8). Smokers: 4-5 hours. Congestive heart failure/hepatic cirrhosis: >24 hours.
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 (10% unchanged) and hepatic metabolism (90%). Metabolites excreted in urine.
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