Comparative Pharmacology
Head-to-head clinical analysis: SOMOPHYLLIN DF versus XOPENEX.
Peer-Reviewed Evidence
Head-to-head clinical analysis: SOMOPHYLLIN DF versus XOPENEX.
SOMOPHYLLIN-DF vs XOPENEX
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Theophylline relaxes bronchial smooth muscle by inhibiting phosphodiesterase, increasing intracellular cAMP, and blocking adenosine receptors.
Selective beta-2 adrenergic receptor agonist that relaxes bronchial smooth muscle by increasing intracellular cyclic AMP levels.
Oral: 300-600 mg every 12 hours; extended-release tablets. Titrate to serum theophylline concentration of 5-15 mcg/mL.
Nebulized solution: 0.63 mg or 1.25 mg 3 times daily every 6-8 hours; metered-dose inhaler: 2 inhalations (90 mcg per inhalation) 3 times daily every 6-8 hours.
None Documented
None Documented
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).
Terminal elimination half-life: 3.3-4.0 hours in adults. Clinically, twice-daily dosing is not recommended due to shorter half-life; every 4-6 hour dosing is standard for acute bronchodilation.
Renal excretion of unchanged drug: approximately 10%; hepatic metabolism accounts for >90% of elimination; metabolites are excreted renally. Less than 5% eliminated in feces.
Renal: 80-100% as unchanged drug and metabolites (approximately 60% as unchanged levalbuterol, 20% as inactive sulfate conjugate). Fecal: <5%.
Category C
Category C
Bronchodilator
Bronchodilator