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Mixed alpha/beta-adrenergic agonist (vasopressor) Pregnancy: Studies in animals have shown a teratogenic effect. Clinical data from epidemiological studies on a limited number of women appear to indicate no particular effects of ephedrine with respect to malformation. Isolated cases of maternal hypertension have been described after abuse or prolonged use of vasoconstrictor amines. Ephedrine crosses the placenta and this has been associated with an increase in fetal heart rate and beat-to-beat variability. Therefore ephedrine should be avoided or used with caution, and only if necessary, during pregnancy. Breastfeeding: ephedrine is excreted in breast milk; irritability and disturbed sleep patterns have been reported in breast-fed infants. Ephedrine is eliminated within 21 to 42 hours after administration, so a decision needs to be made on whether to avoid ephedrine therapy or suspend lactation for 2 days following its administration, taking into account the benefit of breastfeeding for the child and of therapy for the woman. Fertility: no data available.

Ephedrine hydrochloride

Brand names: various

Ephedrine hydrochloride is a sympathomimetic agent used in anaesthesia, given by injection to treat hypotension, particularly that caused by spinal or epidural anaesthesia.

Adult dose

Dose: Reversal of hypotension from spinal or epidural anaesthesia: up to 30 mg in increments of 3 - 7.5 mg, given by slow intravenous injection after the development of hypotension
Route: Intravenous (slow injection)
Frequency: In increments of 3 - 7.5 mg, given after hypotension has developed (the SPC states no dosing interval)
Max: Up to 30 mg in total (SPC: 'Up to 30 mg in increments of 3 - 7.5 mg'); the SPC does not state a time period for this total
The pinned product, Ephedrine Hydrochloride 30 mg/ml Solution for Injection (eMC product 9291), is licensed in section 4.1 only for 'Reversal of hypotension from spinal or epidural anaesthesia', which is the vasopressor use of this page. ROUTE THIS CARD DOES NOT COVER: oral (PO) - this is an injection SPC ('Method of administration: Intravenous use'), so no oral dose is given. Hypotension from causes other than spinal or epidural anaesthesia (e.g. general anaesthesia, sepsis, other shock states) is not a licensed indication of this product and no dose is given for it. Preparation: 'For instructions on dilution of the medicinal product before administration, see section 6.6' - section 6.6 was not retrieved, so no dilution instruction is given here; check the solution is clear and contains no visible particles before administration. Adults and the elderly: same posology. Paediatric: 'generally not recommended for use in children due to insufficient data on efficacy, safety and dosage recommendations'; safety and efficacy under 12 years have not been established (no data); 'Children over 12 years: the posology and method of administration is the same as for adults.' Caution: ephedrine should be avoided or used with caution in patients undergoing anaesthesia with cyclopropane, halothane or other halogenated anaesthetics (they may induce ventricular fibrillation), and the SPC lists halogenated volatile anaesthetics as a combination with a risk of perioperative hypertensive crisis and serious ventricular arrhythmias.

Dose adjustments

Renal

The retrieved SPC sections (4.2-4.8) contain no renal-impairment dosing guidance; no adjustment is stated and none is asserted here.

Hepatic

The retrieved SPC sections (4.2-4.8) contain no hepatic-impairment dosing guidance; no adjustment is stated and none is asserted here.

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Hypersensitivity to the active substance or to any of the excipients
  • In combination with other indirect sympathomimetic agents such as phenylpropanolamine, phenylephrine, pseudoephedrine and methylphenidate
  • In combination with alpha sympathomimetic agents
  • In combination with non-selective monoamine oxidase inhibitors (MAOIs) or within 14 days of their withdrawal

Side effects

  • Common: confusion, anxiety, depression; nervousness, irritability, restlessness, weakness, insomnia, headache, sweating
  • Common: palpitations, hypertension, tachycardia; dyspnoea; nausea, vomiting
  • Rare: cardiac arrhythmias; acute urinary retention
  • Not known: angina pain, reflex bradycardia, cardiac arrest, hypotension; cerebral haemorrhage; pulmonary oedema
  • Not known: hypersensitivity; psychotic states, fear; tremor, hypersalivation; episodes of angle-closure glaucoma; reduced appetite; hypokalaemia, changes in blood glucose levels; primary haemostasis modifications

Interactions

  • Contraindicated combinations: indirect sympathomimetic agents (phenylpropanolamine, pseudoephedrine, phenylephrine, methylphenidate) and alpha sympathomimetics - risk of vasoconstriction and/or acute hypertension; non-selective MAO inhibitors - paroxysmal hypertension, possibly fatal hyperthermia
  • Combinations not recommended: ergot alkaloids, selective MAO-A inhibitors (given concomitantly or within the last 2 weeks), linezolid - risk of vasoconstriction and/or episodes of hypertension
  • Combinations not recommended: tricyclic antidepressants (e.g. imipramine), noradrenergic-serotoninergic antidepressants (milnacipran, venlafaxine), sibutramine - paroxysmal hypertension with possibility of arrhythmias; guanethidine and related products - substantial increase in blood pressure
  • Halogenated volatile anaesthetics - risk of perioperative hypertensive crisis and serious ventricular arrhythmias
  • Cardiac glycosides, quinidine, tricyclic antidepressants - increased risk of arrhythmias
  • Antihypertensive therapy - special care as ephedrine increases blood pressure; interactions with alpha- and beta-blocking drugs may be complex (propranolol and other beta-blockers antagonise beta2 agonist effects)
  • Theophylline - insomnia, nervousness and gastrointestinal complaints; corticosteroids - ephedrine increases the clearance of dexamethasone; antiepileptics - increased plasma concentration of phenytoin and possibly phenobarbitone and primidone
  • Doxapram - risk of hypertension; oxytocin - hypertension with vasoconstrictor sympathomimetics; reserpine and methyldopa may reduce the vasopressor action of ephedrine

Monitoring

  • Use with caution in patients particularly susceptible to its effects, especially hyperthyroidism
  • Great care in cardiovascular disease (ischaemic heart disease, arrhythmia or tachycardia, occlusive vascular disorders including arteriosclerosis, hypertension, aneurysms); angina pain may be precipitated in angina pectoris
  • Care in diabetes mellitus, closed-angle glaucoma and prostatic hypertrophy
  • Special care in patients receiving antihypertensive therapy (ephedrine increases blood pressure)
  • Hypokalaemia associated with high doses of beta2 agonists may increase susceptibility to digitalis-induced arrhythmias
  • Athletes: the preparation contains an active substance which might give a positive reaction in anti-doping tests

Clinical monograph

How it works

It acts both directly on adrenoceptors and indirectly by promoting noradrenaline release, producing increases in heart rate, contractility and blood pressure with mixed alpha and beta activity.

Prescribing in practice

  • It can cause hypertension, tachycardia and arrhythmias, so titrate carefully and use cautiously in patients with cardiovascular disease, hyperthyroidism or diabetes.
  • Tachyphylaxis can occur with repeated dosing as noradrenaline stores become depleted, reducing the response.
  • Avoid or use with great caution in patients taking monoamine oxidase inhibitors, in whom an exaggerated pressor response may occur.

Monitoring

Monitor blood pressure and heart rate closely after each dose during anaesthesia.

Counselling the patient

  • Team: anticipate tachyphylaxis with repeated boluses.
  • Team: monitor for tachycardia and hypertension, especially in cardiac patients.

Evidence & guidelines

Ephedrine is an established vasopressor for the management of anaesthesia-induced hypotension, particularly after neuraxial blockade.

Reference: AAGBI Obstetric Anaesthetists Association guidelines; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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