Carvedilol Tablets

Mechanism

Carvedilol blocks β1 and β2 adrenergic receptors along with α1 receptors, resulting in decreased heart rate, reduced myocardial contractility, and peripheral vasodilation. This dual action helps in lowering blood pressure and improving cardiac function.

Pharmacokinetics

• Absorption: Well absorbed after oral administration but undergoes extensive first-pass metabolism, resulting in bioavailability of about 25–35%. Food delays absorption but does not significantly affect overall bioavailability.
• Distribution: Highly protein bound (approximately 98%) and widely distributed due to its lipophilic nature.
• Metabolism: Extensively metabolized in the liver by oxidation and glucuronidation to active metabolites.
• Elimination: Primarily excreted via bile and feces, with a small portion eliminated through urine. The elimination half-life is approximately 6–10 hours.

Side Effects

• Dizziness
• Fatigue
• Hypotension
• Bradycardia
• Weight gain

Contraindication

• Hypercalcemia
• Severe renal impairment
• Kidney stones
• Hypersensitivity to any component

Interaction

• Calcium channel blockers (e.g., verapamil, diltiazem)
• Digoxin (increased levels)
• Antidiabetic drugs (may mask hypoglycemia)
• Rifampicin (reduces levels)

Warning and Precautions

• Do not discontinue abruptly
• Use cautiously in asthma and COPD
• Monitor blood pressure and heart rate
• Use cautiously in diabetic patients