Comparative Pharmacology
Head-to-head clinical analysis: DURAPHYL versus SOMOPHYLLIN DF.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DURAPHYL versus SOMOPHYLLIN DF.
DURAPHYL vs SOMOPHYLLIN-DF
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 relaxes bronchial smooth muscle by inhibiting phosphodiesterase, increasing intracellular cAMP, and blocking 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; extended-release tablets. Titrate to serum theophylline concentration of 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.
Terminal elimination half-life: 3–12 hours in healthy adults; prolonged in hepatic impairment (up to 30 hours), congestive heart failure, and in neonates; also prolonged in elderly and patients with fever or viral illness. Half-life is shorter in smokers (4–5 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 excretion of unchanged drug: approximately 10%; hepatic metabolism accounts for >90% of elimination; metabolites are excreted renally. Less than 5% eliminated in feces.
Category C
Category C
Bronchodilator
Bronchodilator