Cardipres Mechanism of Action

Pharmacology: Drug Mechanism: Carvedilol is used for treating high blood pressure and congestive heart failure. Carvedilol blocks receptors of the adrenergic nervous system, the system of nerves in which epinephrine (adrenalin) is active. Nerves from the adrenergic system enter the heart and release an adrenergic chemical (norepinephrine) that attaches to receptors on the heart's muscle and stimulates the muscle to beat more rapidly and forcefully. By blocking the receptors, carvedilol reduce the heart's rate and force of contraction and thereby reduces the work of the heart. Carvedilol also blocks adrenergic receptors on arteries and causes the arteries to relax and the blood pressure to fall. The drop in blood pressure further reduces the work of the heart since it is easier to pump blood against a lower pressure.
Pharmacokinetics: Absorption: Following oral administration, carvedilol is rapidly absorbed. The maximum serum concentration is reached after approximately 1 hr. Approximately 98-99% of carvedilol is bound to plasma proteins. Carvedilol is a lipophilic compound, the distribution volume is approximately 2 L/kg and is during long-term treatment.
Elimination: The average elimination half-life of carvedilol ranges from 6-10 hrs. Plasma clearance is approximately 590 mL/min. Elimination is mainly biliary. The primary route of excretion is via the feces. A minor part is eliminated via the kidneys in the form of various metabolites.
Bioavailability: The absolute bioavailability of carvedilol in humans is approximately 25%. Food does not affect the extent of bioavailability, although the time to reach maximum plasma concentrations is prolonged.
In patients with impaired liver function, bioavailability is raised to as much as 80% due to a reduced first-pass effect.