Provexel Mechanism of Action

Pharmacology: Pharmacodynamics: Salbutamol is a selective short acting beta-2-adrenergic agonist with a preferential effect on beta-2-adrenergic receptors found in the respiratory tract. It stimulates adenyl cyclase, the enzyme which catalyzes the conversion of adenosine triphosphate (ATP) to cyclic-3',5'-adenosine monophosphate (cAMP). CAMP mediates cellular responses such as bronchial smooth muscle relaxation resulting in bronchodilation.
Pharmacokinetics: After oral inhalation of salbutamol, onset of bronchodilation is within 5 to 15 minutes; peaks in 0.5 to 3 hours and persists for 2 to 5 hours; bronchodilation in some patients may persist for up to 6 hours. Much of the salbutamol dose delivered by oral inhalation is deposited on the buccal mucosa and subsequently swallowed and absorbed from gastrointestinal tract.
Salbutamol is metabolized in the liver, being converted to salbutamol 4'-O-sulfate. This is then excreted in the urine and feces. In patients with asthma, about 70% of the inhaled dose is excreted in urine as unchanged drug and metabolites within 24 hours, and 80 to 100% within 72 hours; about 30% of the inhaled dose is excreted unchanged in the urine in 24 hours. About 10% of the inhaled dose may be excreted in the feces.
Animal studies show that salbutamol is capable of crossing the blood-brain barrier and the placenta. It may be secreted in breast milk, but concentrations are not known.