ADMINISTRATION ROUTES:
PO
ALTERNATIVE NAMES:
Cardinol, Drofate
ICU INDICATIONS:
- Thyrotoxic crisis
- Need for centrally acting beta blocker
PRESENTATION AND ADMINISTRATION:
PO:
Tablets:
Cardinol 10 mg tablets (red) and 40 mg (red)
Long Acting Capsules:
Cardinol LA 160 mg modified release capsule
DOSAGE:
PO:
Thyrotoxicosis:
10 - 40 mg TDS or QID
Max total daily dose 320 mg, given in divided doses
DOSAGE IN RENAL FAILURE AND RENAL REPLACEMENT THERAPY:
Dose in renal impairment
| GFR (ml/min) | DOSE |
|---|---|
| <10 | start with low doses |
| 10-20 | start with low doses |
| >20-50 | dose as in normal renal function |
Dose in renal replacement therapy
| MODALITY | DOSE |
|---|---|
| CAPD | start with low doses |
| HD | start with low doses |
| CVVHDF | start with low doses |
DOSAGE IN PAEDIATRICS:
PO:
0.2 - 0.5 mg/kg 6-12 hourly
Slowly increase to 1.5 mg/kg 6-12 hrly if required
CLINICAL PHARMACOLOGY:
Propranolol hydrochloride is a synthetic non-selective beta-adrenergic receptor blocking agent. It is the first line agent for thyrotoxicosis because it reduces peripheral conversion of T4 to T3.
CONTRAINDICATIONS:
- Sinus bradycardia
- Heart block greater than first degree
- Cardiogenic shock
- Overt cardiac failure
- Asthma
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 may precipitate a thyroid storm.
PRECAUTIONS:
General:
Beta blockers may aggravate peripheral arterial circulatory disorders.
Laboratory Tests:
No tests in addition to routine ICU tests are required
Drug/Laboratory Test Interactions: None known
IMPORTANT DRUG INTERACTIONS IN ICU:
Beta blockers may exacerbate the rebound hypertension which can follow the withdrawal of clonidine
ADVERSE REACTIONS:
Body as a Whole:
Tiredness, fatigue
Cardiovascular System:
Bradycardia, cold extremities, hypotension, leg pain
Respiratory System:
Wheeziness, dyspnoea
Digestive System:
Diarrhoea, nausea
Nervous System:
Dizziness, vertigo, light-headedness