Comparative Pharmacology
Head-to-head clinical analysis: LUFYLLIN versus QUIBRON T SR.
Head-to-head clinical analysis: LUFYLLIN versus QUIBRON T SR.
LUFYLLIN vs QUIBRON-T/SR
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
LUFYLLIN (dyphylline) is a xanthine bronchodilator that inhibits phosphodiesterase, increasing intracellular cAMP levels, leading to relaxation of bronchial smooth muscle and suppression of airway hyperresponsiveness. It also antagonizes adenosine receptors.
Theophylline is a methylxanthine that relaxes bronchial smooth muscle by inhibiting phosphodiesterase, increasing intracellular cAMP, and antagonizing adenosine receptors.
200-400 mg orally 3-4 times daily, not to exceed 1600 mg/day. Also available as 200 mg/mL injection, administer 200-400 mg IM or slow IV every 6-8 hours.
200-400 mg orally every 12 hours; extended-release tablets. Initial dose 200 mg every 12 hours; may increase by 200 mg daily every 3-7 days based on serum theophylline levels (target 5-15 mcg/mL). Maximum 800 mg/day.
None Documented
None Documented
6-8 hours in adults with normal hepatic and renal function. In neonates, half-life is prolonged to 20-30 hours. In patients with hepatic cirrhosis, half-life may extend to 20-30 hours. In congestive heart failure, half-life is prolonged to 12-20 hours.
Terminal t1/2: 3-12 hours (adults); 1-9 hours (children); prolonged in cirrhosis (up to 30 hours), heart failure, elderly. Clinical context: Narrow therapeutic index (5-15 mcg/mL); dosing interval adjusted based on t1/2.
Primarily renal excretion of unchanged drug and metabolites. Approximately 50% is excreted unchanged in urine, with the remainder as metabolites (including 7-hydroxypropyltheophylline and 1,3-dimethyluric acid). Biliary/fecal elimination accounts for <10%.
Renal: ~10% unchanged; Hepatic metabolism (CYP1A2, CYP3A4): 90% to inactive metabolites (1,3-dimethyluric acid, 3-methylxanthine, 1-methyluric acid). Biliary/fecal: minimal (<5%).
Category C
Category C
Xanthine Bronchodilator
Xanthine Bronchodilator