Comparative Pharmacology
Head-to-head clinical analysis: SOMOPHYLLIN versus SOMOPHYLLIN DF.
Peer-Reviewed Evidence
Head-to-head clinical analysis: SOMOPHYLLIN versus SOMOPHYLLIN DF.
SOMOPHYLLIN vs SOMOPHYLLIN-DF
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 levels, and antagonizing adenosine receptors. It also has anti-inflammatory and immunomodulatory effects.
Theophylline relaxes bronchial smooth muscle by inhibiting phosphodiesterase, increasing intracellular cAMP, and blocking adenosine receptors.
Oral: 200–400 mg every 6 hours; IV: 6 mg/kg loading dose over 30 minutes, then 0.4–0.6 mg/kg/h continuous infusion.
Oral: 300-600 mg every 12 hours; extended-release tablets. Titrate to serum theophylline concentration of 5-15 mcg/mL.
None Documented
None Documented
The terminal elimination half-life of theophylline is approximately 8 hours in healthy non-smoking adults (range 3-12 hours). It is prolonged in patients with hepatic cirrhosis (up to 30 hours), heart failure (up to 30 hours), and in neonates (20-30 hours). Smoking (including marijuana) decreases half-life to 4-5 hours. Half-life is shorter in children (3-5 hours). Clinical context: Due to narrow therapeutic index, half-life variability necessitates therapeutic drug monitoring.
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).
Theophylline is primarily eliminated by hepatic metabolism (>90%), with only about 10-15% excreted unchanged in urine. Renal excretion of the parent drug is minor; however, metabolites are excreted renally. Biliary/fecal excretion accounts for less than 1%.
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