Comparative Pharmacology
Head-to-head clinical analysis: SOMOPHYLLIN versus SOMOPHYLLIN CRT.
Peer-Reviewed Evidence
Head-to-head clinical analysis: SOMOPHYLLIN versus SOMOPHYLLIN CRT.
SOMOPHYLLIN vs SOMOPHYLLIN-CRT
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 acts as a bronchodilator via nonselective phosphodiesterase inhibition, increasing intracellular cAMP levels. It also antagonizes adenosine receptors and may have anti-inflammatory effects.
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.
Theophylline 400 mg orally once daily (24-hour extended-release). Titrate based on serum theophylline levels; target trough 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: 8-10 hours in adults (non-smokers); prolonged to 12-16 hours in elderly or hepatic impairment; reduced to 4-6 hours in smokers (CYP1A2 induction).
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%.
Primarily hepatic metabolism (90%) via CYP1A2 and CYP3A4; renal excretion of unchanged drug accounts for ~10% in adults, with minor biliary/fecal elimination (<1%).
Category C
Category C
Bronchodilator
Bronchodilator