Comparative Pharmacology
Head-to-head clinical analysis: SOMOPHYLLIN versus THEOLAIR SR.
Peer-Reviewed Evidence
Head-to-head clinical analysis: SOMOPHYLLIN versus THEOLAIR SR.
SOMOPHYLLIN vs THEOLAIR-SR
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 antagonizing 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; sustained-release formulation; adjust based on serum theophylline concentrations (target 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.
Adults: 8 hours (range 5-12). Children: 3.5 hours (range 1-8). Smokers: 4-5 hours. Congestive heart failure/hepatic cirrhosis: >24 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 (10% unchanged) and hepatic metabolism (90%). Metabolites excreted in urine.
Category C
Category C
Bronchodilator
Bronchodilator