Indications
Ephedrine is indicated to reverse hypotension induced by spinal or epidural anaesthesia. It is of little value in hypotensive crisis due to shock, circulatory collapse, or haemorrhage.
Pharmacology
Ephedrine is a stimulant drug, belonging to a group of medicines known as sympathomimetics. Specifically it is both an alpha and beta adrenergic agonist. In addition, Ephedrine enhances the release of norepinephrine, a strong endogenous alpha agonist. The action of this compound is notably similar to that of the body's primary adrenergic hormone epinephrine (adrenaline), which also exhibits action toward both alpha and beta receptors. When administered, Ephedrine will notably increase the activity of the central nervous system, as well as have a stimulatory effect on other target cells.
Dosage And Administration
To reverse hypotension induced by spinal or epidural anaesthesia 3 to 6 mg (or at most 9 mg) Ephedrine Hydrochloride is given by slow intravenous injection and repeated every 3 to 4 minutes as required; the maximum total dose is 30 mg. Ephedrine has also been given by intramuscular or subcutaneous injection.
Interaction
Administration of Ephedrine may cause a hypertensive crisis in patients receiving an Monoamine Oxidase Inhibitor (including an Reversible Inhibitor of Monoamine Oxidase type A). Ephedrine should be avoided or used with care in patients undergoing anaesthesia with cyclopropane, halothane, or other volatile anaesthetics. An increased risk of arrhythmias may occur if given to patients receiving cardiac glycosides, quinidine, or tricyclic antidepressants, and there is an increased risk of vasoconstrictor or pressor effects in patients receiving ergot alkaloids or oxytocin
Contraindications
The use of Ephedrine is contraindicated in the presence of coronary thrombosis. It should be used with caution in patients with organic heart disease, cardiac decompensation, hyperthyroidism, hypertension, and angina pectoris, and in patients receiving digitalis.
Side Effects
Adverse effects reported are nausea, vomiting, anorexia; tachycardia (sometimes bradycardia), arrhythmias, anginal pain, vasoconstriction with hypertension, vasodilation with hypotension, dizziness and flushing; dyspnoea; headache, anxiety, restlessness, confusion, psychoses, insomnia, tremor; difficulty in micturition, urine retention; sweating, hypersalivation; changes in blood-glucose concentration; very rarely angle-closure glaucoma.
Pregnancy And Lactation
Pregnancy: Category C. Either studies in animals have revealed adverse effects on the foetus (teratogenic or embryocidal or other) and there are no controlled studies in women or studies in women and animals are not available. Drugs should be given only if the potential benefit justifies the potential risk to the foetus.
Lactation: Ephedrine Hydrochloride is distributed into breast milk, and therefore Ephedrine Hydrochloride Injection is not recommended for use during lactation because of the risk of adverse effects in the infant.
Precautions And Warnings
Ephedrine should be given with care to patients with hyperthyroidism, diabetes mellitus, ischemic heart disease, hypertension, renal impairment, or angle-close glaucoma. In patients with prostatic enlargement, Ephedrine may increase difficulty with micturition. Use in pregnancy and lactation: Increased fetal heart rate reported with parenteral Ephedrine. Irritability and disturbed sleep have been reported in breast-fed infants.
Overdose Effects
When given in sufficiently large doses Ephedrine gives rise in most patients to certain minor reactions, such as giddiness, headache, nausea, vomiting, sweating, palpitations, difficulty in micturition, tremors, anxiety, restlessness and insomnia; some patients may exhibit these symptoms even with the usual therapeutic dosage.
Therapeutic Class
Other adrenoceptor stimulants, Vasoconstrictor/Venotonic
Storage Conditions
Store in a cool, dry place, protected from light. Keep all medicines out of reach of children.