Comparative Pharmacology
Head-to-head clinical analysis: DURAPHYL versus THEOLAIR SR.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DURAPHYL versus THEOLAIR SR.
DURAPHYL vs THEOLAIR-SR
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Bronchodilator via beta-2 adrenergic receptor agonism; increases cAMP, relaxes bronchial smooth muscle.
Theophylline is a methylxanthine that relaxes bronchial smooth muscle by inhibiting phosphodiesterase, increasing cAMP, and antagonizing adenosine receptors.
5 mg orally twice daily, increased to 10 mg twice daily after one week if tolerated; maximum dose 20 mg twice daily.
Oral: 300-600 mg every 12 hours; sustained-release formulation; adjust based on serum theophylline concentrations (target 5-15 mcg/mL).
None Documented
None Documented
Terminal elimination half-life is 7–9 hours in adults with normal hepatic function; prolonged to 20–30 hours in hepatic cirrhosis or heart failure. In neonates, half-life may exceed 30 hours due to immature CYP450 enzymes.
Adults: 8 hours (range 5-12). Children: 3.5 hours (range 1-8). Smokers: 4-5 hours. Congestive heart failure/hepatic cirrhosis: >24 hours.
Primarily hepatic metabolism (CYP1A2, CYP3A4) with renal excretion of metabolites. Less than 10% excreted unchanged in urine; approximately 70% recovered in urine as metabolites, 30% in feces.
Renal (10% unchanged) and hepatic metabolism (90%). Metabolites excreted in urine.
Category C
Category C
Bronchodilator
Bronchodilator