1. Introduction
Carvedilol, marketed under brand names such as Coreg and Dilatrend, is a non-selective beta-blocker with alpha-blocking activity. It is used to manage hypertension, heart failure, and left ventricular dysfunction after a myocardial infarction. Its dual mechanism of action reduces heart rate, lowers blood pressure, and improves cardiac output in heart failure.
2. Indications
- Approved Indications:
- Hypertension.
- Symptomatic heart failure.
- Left ventricular dysfunction following a myocardial infarction.
- Off-Label Uses:
- Atrial fibrillation with rapid ventricular response (rate control).
3. Dosage
- Hypertension:
- Initial dose: 6.25 mg twice daily.
- Maintenance dose: 25 mg twice daily.
- Maximum dose: 50 mg/day in divided doses.
- Heart Failure:
- Initial dose: 3.125 mg twice daily.
- Gradually increase every 2 weeks to a maximum dose of 25 mg twice daily (for patients ≤85 kg) or 50 mg twice daily (for patients >85 kg).
- Post-Myocardial Infarction:
- Initial dose: 6.25 mg twice daily.
- Maintenance dose: 25 mg twice daily.
4. Administration
- Take with food to reduce the risk of orthostatic hypotension.
- Tablets should be swallowed whole; do not crush or chew.
5. Forms Available
- Tablets: 3.125 mg, 6.25 mg, 12.5 mg, 25 mg.
- Extended-release capsules: 10 mg, 20 mg, 40 mg, 80 mg.
6. Side Effects
6.1. Common Side Effects
- Dizziness.
- Fatigue.
- Hypotension.
- Bradycardia (slow heart rate).
6.2. Less Common Side Effects
- Peripheral oedema.
- Diarrhoea.
- Weight gain.
6.3. Rare but Serious Side Effects
- Bronchospasm in patients with asthma or chronic obstructive pulmonary disease (COPD).
- Severe bradycardia or heart block.
- Hepatotoxicity.
7. Warnings
- Contraindicated in patients with severe hepatic impairment.
- Avoid in patients with decompensated heart failure requiring inotropic support.
- Use cautiously in patients with diabetes, as carvedilol can mask symptoms of hypoglycaemia (e.g., tachycardia).
- Avoid abrupt discontinuation, as it may lead to rebound hypertension or angina.
8. Precautions
- Monitor closely in patients with bronchospastic diseases, as carvedilol may worsen symptoms.
- Use cautiously in patients with a history of severe allergic reactions, as beta-blockers may reduce the effectiveness of epinephrine.
9. Interactions
- Drug-Drug Interactions:
- Calcium channel blockers (e.g., verapamil, diltiazem): May increase the risk of bradycardia and hypotension.
- CYP2D6 inhibitors (e.g., fluoxetine, paroxetine): May increase carvedilol plasma levels.
- Antidiabetic agents: Enhanced risk of hypoglycaemia or delayed recognition of symptoms.
- Drug-Food Interactions:
- Take with food to reduce the risk of orthostatic hypotension.
10. Monitoring Parameters
- Blood pressure and heart rate regularly.
- Signs of heart failure exacerbation (e.g., weight gain, dyspnoea).
- Blood glucose levels in diabetic patients.
- Liver function tests periodically in long-term use.
11. Use in Children
- Safety and efficacy in children have not been established; not typically recommended.
12. Use in Pregnancy
- Category C: Limited data available; use only if the potential benefit outweighs the risk to the foetus.
- May cause foetal bradycardia, hypoglycaemia, or hypotension.
13. Use in Elderly
- Use with caution, as elderly patients are more prone to side effects such as dizziness and hypotension.
14. Use in Kidney Disease
- No specific dose adjustments required; use cautiously in patients with severe renal impairment.
15. Use in Liver Disease
- Contraindicated in severe hepatic impairment due to increased risk of toxicity.
16. Patient Counselling Points
- Take carvedilol with food to reduce dizziness or light-headedness.
- Do not abruptly stop taking the medication, as this may worsen heart conditions or cause rebound hypertension.
- Inform patients about the potential side effects, including dizziness, fatigue, or slow heart rate, and advise them to report severe symptoms.
- Diabetic patients should monitor blood glucose closely, as symptoms of hypoglycaemia may be masked.
- Avoid alcohol, as it may enhance the hypotensive effects of the medication.
17. Table of Brand Names, Manufacturers, and Prices
Brand Name | Manufacturer | Price (USD) |
---|---|---|
Coreg | GlaxoSmithKline | $25–40 (30 tablets, 25 mg) |
Dilatrend | Roche | $30–50 (30 tablets, 25 mg) |
Generic Options | Various | $10–20 (30 tablets, 25 mg) |
18. FAQs (15 Questions)
- What is carvedilol used for?
Carvedilol is used to treat hypertension, heart failure, and left ventricular dysfunction after a heart attack. - How does carvedilol work?
It is a beta-blocker with alpha-blocking activity that reduces heart rate, lowers blood pressure, and improves blood flow. - What are the common side effects of carvedilol?
Dizziness, fatigue, bradycardia, and hypotension. - Can carvedilol cause weight gain?
Yes, weight gain may occur, particularly in patients with heart failure. - How should carvedilol be taken?
It should be taken with food to reduce the risk of orthostatic hypotension. - Is carvedilol safe for children?
Safety and efficacy in children have not been established. - Can pregnant women take carvedilol?
It should only be used during pregnancy if the benefits outweigh the risks. - Can carvedilol cause low blood sugar?
It can mask symptoms of hypoglycaemia in diabetic patients, so caution is needed. - What should I do if I miss a dose?
Take the missed dose as soon as you remember, but skip it if it’s close to the next dose. Do not double up. - Can I stop taking carvedilol suddenly?
No, sudden discontinuation may worsen heart conditions or cause rebound hypertension. - Does carvedilol interact with other medications?
Yes, it interacts with calcium channel blockers, CYP2D6 inhibitors, and antidiabetic drugs. - Can carvedilol be used for heart failure?
Yes, it is commonly used to manage heart failure and improve symptoms. - How long does it take for carvedilol to work?
Effects on blood pressure may be seen within hours, but full benefits for heart failure may take weeks to months. - Does carvedilol cause tiredness?
Yes, fatigue is a common side effect, especially during the initial phase of treatment. - How should carvedilol be stored?
Store at room temperature, away from moisture and heat.