Comparative Pharmacology
Head-to-head clinical analysis: SOMOPHYLLIN versus THEOBID.
Peer-Reviewed Evidence
Head-to-head clinical analysis: SOMOPHYLLIN versus THEOBID.
SOMOPHYLLIN vs THEOBID
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 is a methylxanthine that relaxes bronchial smooth muscle by inhibiting phosphodiesterase, increasing cAMP, and blocking adenosine receptors. It also has anti-inflammatory and immunomodulatory 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 extended-release capsules: 300-600 mg/day orally divided every 12 hours. Initial dose 300 mg/day, titrate based on serum concentrations (target 10-20 mcg/mL). Max 600 mg/day unless serum levels monitored.
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.
Neonates: 24-36 h; Children (1-9 y): 3-4 h; Adults (non-smokers): 6-12 h; Adults (smokers): 4-5 h; Hepatic cirrhosis: prolonged (up to 30 h); Heart failure: prolonged (up to 20 h).
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 (10% unchanged), hepatic metabolism (90%, primarily via CYP1A2 and CYP3A4); 20% excreted in feces as metabolites.
Category C
Category C
Bronchodilator
Bronchodilator