Caraten Mechanism of Action

Pharmacodynamics: Mechanism of Action: Systemic: Carvedilol is a nonselective beta-adrenergic blocking agent with alpha 1-adrenergic blocking activity and no intrinsic sympathomimetic activity. The exact mechanism of the antihypertensive effect produced by beta-adrenergic blockade, may involve suppression of renin production. The beta-adrenergic blocking activity of carvedilol decreases cardiac output, exercise- and /or isoproterenol-induced tachycardia, and reflex orthostatic tachycardia. The alpha 1-adrenergic blocking activity of carvedilol blunts the pressor effect of phenylephrine, causes vasodilation, and reduces peripheral vascular resistance. The effect of alpha1-adrenergic blockade is a reduction in standing blood pressure (more than supine), presenting symptoms of postural hypotension and possibly syncope.
The mechanism by which carvedilol produces a beneficial effect in congestive heart failure is not known, but may be attributable to beta-adrenergic blockade and vasodilation.
Pharmacokinetics: Onset: hypertension, oral: Initial Response 1 hour, Peak Response 4 to 7 hours.
Duration: Single Dose, Hypertension, Oral: 24 hours.
Absorption: Rapid and extensive.
Bioavailability: 25 to 35%; food slows absorption.
Protein Binding: 95% to 98%.
Distribution: Volume of Distribution 115 L.
Metabolism: Hepatic: extensively via P450 2D6 pathway; Active metabolite: 4'-hydroxyphenyl.
Excretion: Fecal/Biliary.
Elimination Half Life: Carvedilol 6 to 10 h.