Carvedilol

ADMINISTRATION ROUTES:

PO / NG

ALTERNATIVE NAMES:

Dilatrend

ICU INDICATIONS:

1. Hypertension
2. Acute myocardial infarction
3. Secondary prevention in patients with coronary artery disease
4. Angina
5. Rate control

PRESENTATION AND ADMINISTRATION:

PO/NG:

Dilatrend tablets 6.25 mg (yellow), 12.5 mg (light brown), 25 mg (white to pale yellowish beige)

When administered with food, the rate of absorption is slowed. Carvedilol should be taken with food to minimise the risk of hypotension.

DOSAGE:

PO/NG:

Start at 3.125 mg BD and increase gradually as required

DOSAGE IN RENAL FAILURE AND RENAL REPLACEMENT THERAPY:

Dose as in normal renal function

DOSAGE IN PAEDIATRICS:

0.08 mg/kg BD If tolerated, increase gradually to a maximum of 0.5-0.75 mg/kg BD

CLINICAL PHARMACOLOGY:

Non selective beta blocker and alpha-1 blocker. Carvedilol is rapidly absorbed following oral administration. Following oral administration, the apparent mean terminal elimination half-life of carvedilol generally ranges from 7 - 10 hours.

CONTRAINDICATIONS:

1. Bronchial asthma (two cases of death from status asthmaticus have been reported in patients receiving single doses of carvedilol)

2. Second- or third-degree AV block, sick sinus syndrome or severe bradycardia (unless a permanent pacemaker is in place)

3. Cardiogenic shock

4. Clinically manifest hepatic impairment

5. Hypersensitivity to any component of the product.

WARNINGS:

Cardiac Failure

Sympathetic stimulation is necessary in supporting circulatory function in congestive heart failure and beta blockade carries the potential hazard of further depressing myocardial contractility and precipitating more severe failure

Discontinuation of therapy

Discontinuation of therapy in a patient with coronary artery disease may lead to rebound angina, arrhythmia or myocardial infarction

Diabetes and Hypoglycaemia

Beta blockers may mask tachycardia occurring with hypoglycaemia

Thyrotoxicosis

Beta-adrenergic blockade may mask certain clinical signs (e.g. tachycardia) of hyperthyroidism. Abrupt withdrawal of beta blockade might precipitate a thyroid storm

PRECAUTIONS:

General:

Carvedilol may aggravate peripheral arterial circulatory disorders.

Nonallergic Bronchospasm (e.g. chronic bronchitis and emphysema)

Patients with bronchospastic disease should, in general, not receive beta-blockers. Carvedilol may be used with caution, however, in patients who do not respond to, or cannot tolerate, other antihypertensive agents. If used, the smallest effective dose should be given. In clinical trials of patients with congestive heart failure, patients with bronchospastic disease were enrolled if they did not require oral or inhaled medication to treat their bronchospastic disease

Laboratory Tests: No tests additional to standard ICU tests are required

Drug/Laboratory Test Interactions: None known

IMPORTANT DRUG INTERACTIONS IN ICU:

Clonidine:

Concomitant administration of clonidine with carvedilol may potentiate blood pressure and heart rate-lowering effects due to both agents possessing alpha-2 blocking properties

Cyclosporin:

On the average, the required dose of cyclosporin reduces by about 20% after initiation of carvedilol therapy. Close monitoring of cyclosporin levels is required

Digoxin:

Digoxin concentrations are increased by about 15% when digoxin and carvedilol are administered together. Both digoxin and carvedilol slow AV conduction. Therefore, increased monitoring of digoxin is recommended when initiating, adjusting or discontinuing carvedilol

Rifampin:

Rifampin reduces plasma concentrations of carvedilol by about 70%

ADVERSE REACTIONS:

Body as a whole:

Fatigue

Cardiovascular System:

Bradycardia, hypotension, syncope, angina

Gastrointestinal System:

Diarrhoea, nausea, vomiting

Musculoskeletal System:

Arthralgia

Respiratory System:

Cough

Nervous System:

Dizziness, headache