Aeronide Mechanism of Action

Pharmacology: Pharmacodynamics: Budesonide is a glucocorticosteroid which possesses a high local anti-inflammatory action, with a lower incidence and severity of adverse effects than those seen with oral corticosteroids.
Pharmacokinetics: Absorption: After a single dose of 1 mg budesonide, a peak plasma concentration of 2.6 nmol/L was obtained approximately 20 minutes after nebulization in asthmatic children 4 to 6 years of age. The exposure (AUC) of budesonide following administration of a single 1 mg close of budesonide by nebulization to asthmatic children 4 to 6 years of age is comparable to healthy adults given a single 2 mg close by nebulization. In asthmatic children 4 to 6 years of age, the Total absolute bioavailability (ie, lung + oral) following administration of budesonide inhalation suspension via jet nebulizer was approximately 6% of the labeled dose. The peak plasma concentration of budesonide occurred 10 to 30 minutes after start of nebulization.
Distribution: In asthmatic children 4 to 6 years of age, the volume of distribution at steady-state of budesonide was 3 L/kg, approximately the same as in healthy adults. Budesonide is 85% to 90% bound to plasma proteins, the degree of binding being constant over the concentration range (1 to 100 nmol/L) achieved with, and exceeding, recommended doses. Budesonide showed little or no binding to corticosteroid-binding globulin. Budesonide rapidly equilibrated with concentration independent manner with a blood/plasma ratio of approximately 0.8.
Metabolism: In vitro studies with human liver homogenates have shown that budesonide is rapidly and extensively metabolized. Two major metabolites formed via cytochrome P450 (CYP) isoenzyme 3A4 (CYP3A4) catalyzed biotransformation have been isolated and identified as 16-hydroxyprednisolone and 6-hydroxybudesonide. Budesonide is primarily cleared by the liver. In asthmatic children 4 to 6 years of age, the terminal half-life of budesonide after nebulization is 2.3 hours, and the systemic clearance is 0.5 L/min, which is approximately 50% greater than in healthy adults after adjustment for differences in weight.
Excretion: Budesonide is excreted in urine and feces in the form of metabolites. In adults, approximately 60% of an intravenous radiolabeled dose was recovered in the urine. No unchanged budesonide was detected in the urine.