Comparative Pharmacology
Head-to-head clinical analysis: SOMOPHYLLIN DF versus THEOPHYL 225.
Peer-Reviewed Evidence
Head-to-head clinical analysis: SOMOPHYLLIN DF versus THEOPHYL 225.
SOMOPHYLLIN-DF vs THEOPHYL-225
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Theophylline relaxes bronchial smooth muscle by inhibiting phosphodiesterase, increasing intracellular cAMP, and blocking 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; extended-release tablets. Titrate to serum theophylline concentration of 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
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).
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: approximately 10%; hepatic metabolism accounts for >90% of elimination; metabolites are excreted renally. Less than 5% eliminated in feces.
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