Combivent - Clinical Pharmacology

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Following this single-dose administration, 30. 8 ± 10. 2% of the estimated mouthpiece dose was excreted unchanged in the 24 hour urine. Since albuterol sulfate is rapidly and completely absorbed, this study could not distinguish between pulmonary and gastrointestinal absorption.

Intravenous pharmacokinetics of albuterol were studied in a comparable group of 16 healthy male volunteers; the mean terminal half-life following a 30-minute infusion of 1.5 mg was 3.9 hours with a mean clearance of 439 mL/ min/ 1.73 m 2 .

Intravenous albuterol studies in rats demonstrated that albuterol crossed the blood-brain barrier and reached brain concentrations amounting to about 5% of the plasma concentrations. In structures outside the blood-brain barrier (pineal and pituitary glands), the drug achieved concentrations more than 100 times those in whole brain.

Studies in pregnant rats with tritiated albuterol demonstrated that approximately 10% of the circulating maternal drug was transferred to the fetus. Disposition in fetal lungs was comparable to maternal lungs, but fetal liver disposition was 1% of maternal liver levels.

Studies in laboratory animals (minipigs, rodents, and dogs) have demonstrated the occurrence of cardiac arrhythmias and sudden death (with histologic evidence of myocardial necrosis) when beta-agonists and methylxanthines were administered concurrently. The significance of these findings when applied to humans is unknown.

Combivent Inhalation Aerosol:

Mechanism of Action Combivent Inhalation Aerosol is expected to maximize the response to treatment in patients with chronic obstructive pulmonary disease (COPD) by reducing bronchospasm through two distinctly different mechanisms, anticholinergic (parasympatholytic) and sympathomimetic.

Simultaneous administration of both an anticholinergic (ipratropium bromide) and a beta 2 -sympathomimetic (albuterol sulfate) is designed to benefit the patient by producing a greater bronchodilator effect than when either drug is utilized alone at its recommended dosage.