Carvedilol
Pharmacologic profile and clinical uses
Description/Definition
Carvedilol is a non-selective beta-blocker with alpha-1 blocking activity, widely used in the management of heart failure and hypertension. It provides both vasodilatory effects and reduction in heart rate, which can be beneficial in heart failure management.
Mechanism of action
- Beta-blockade: Carvedilol blocks beta-1 and beta-2 adrenergic receptors, reducing heart rate, myocardial contractility, and myocardial oxygen demand.
- Alpha-1 blockade: Leads to vasodilation, decreasing peripheral vascular resistance and lowering blood pressure.
Indications
- Management of mild to severe chronic heart failure
- Left ventricular dysfunction following myocardial infarction
- Hypertension
Key aspects of drug therapy management
Dosage and administration
- Heart Failure: Start at 3.125 mg BID. Titrate every two weeks, if tolerated, up to a maximum of 25 mg BID for patients weighing less than 85 kg and 50 mg twice daily for those weighing more.
- Hypertension: Start at 6.25 mg twice daily. May increase to 12.5 mg twice daily, with a maximum dose of 25 mg twice daily.
Side effects
Common: Dizziness, fatigue, hypotension, diarrhea, hyperglycemia. Serious: Bradycardia, heart block, worsening heart failure, bronchospasm in susceptible individuals.
Drug interactions
- Additive effects: With other antihypertensives leading to hypotension.
- CYP2D6 inhibitors: May increase carvedilol levels.
- Caution: With drugs that depress myocardial function or AV conduction.
Contraindications
Bronchial asthma or related bronchospastic conditions; Second or third-degree AV block; Severe bradycardia unless a pacemaker is present; Hepatic impairment.
Monitoring
- Monitor blood pressure, heart rate, and signs of worsening heart failure.
- Use with caution in diabetic patients, as carvedilol may mask symptoms of hypoglycemia. Patients should be advised not to discontinue carvedilol abruptly.
- Prognosis: Carvedilol has been shown to reduce mortality and hospitalization in heart failure patients and improve left ventricular ejection fraction.
