Sympathomimetic Vasopressor Pregnancy: US label: available data have not identified a drug-associated risk of major birth defects, miscarriage, or adverse maternal/fetal outcomes; clinical considerations apply due to underlying conditions. (UK SPC for the oral product advises avoiding use in pregnancy.)

Ephedrine (IV — Anaesthesia)

Brand names: Ephedrine

Intravenous ephedrine is a sympathomimetic agent used in anaesthesia to treat hypotension, particularly that associated with spinal or epidural anaesthesia.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 5 mg to 10 mg by IV bolus

Route: Intravenous (bolus)

Frequency: As needed, titrated to effect

Max: Not to exceed a total dosage of 50 mg

For clinically important hypotension in the setting of anaesthesia (US labelling; the UK SPC held in this bundle covers only oral tablets, so the IV posology is taken from the US FDA label - verify against UK SPC / anaesthetic practice). Initial dose 5 to 10 mg by IV bolus; administer additional boluses as needed, not to exceed a total of 50 mg; adjust according to blood pressure goal (titrate to effect). Ephedrine sulfate injection 50 mg/mL must be diluted before IV bolus administration (dilute with normal saline or 5% dextrose); a 5 mg/mL solution is prepared by withdrawing 50 mg (1 mL of 50 mg/mL) and diluting with 9 mL of 5% dextrose or 0.9% sodium chloride. To be administered by trained healthcare providers. Repeated administration can result in tachyphylaxis. For elderly, start at the low end of the dosing range.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

US label states None. (UK SPC for the oral product lists: hypersensitivity; ischaemic heart disease; hypertension; thyrotoxicosis; prostatic hypertrophy - clinician to reconcile for the IV/anaesthesia setting)

Side effects

Nausea, vomiting
Tachycardia, palpitations
Reactive hypertension
Bradycardia, ventricular ectopics
Dizziness, restlessness

Interactions

Oxytocin / oxytocic drugs (e.g. methylergonovine, ergonovine): serious postpartum hypertension and stroke reported - carefully monitor blood pressure
Clonidine, propofol, monoamine oxidase inhibitors (MAOIs), atropine: augment the pressor effect - monitor blood pressure
Alpha-adrenergic antagonists, beta-adrenergic antagonists, reserpine, quinidine, mephentermine: antagonise the pressor effect
Guanethidine: ephedrine may inhibit neuron blockade, causing loss of antihypertensive effectiveness

Clinical monograph

How it works

It has mixed action, directly stimulating alpha and beta adrenoceptors and indirectly releasing noradrenaline, raising blood pressure, heart rate and cardiac output.

Prescribing in practice

It should be given by titrated increments with continuous blood pressure monitoring, as it can cause hypertension, tachycardia and arrhythmias, especially with excessive dosing.
Tachyphylaxis can develop with repeated dosing, so a vasopressor with a different mechanism may be needed if the response diminishes.
It can interact dangerously with monoamine oxidase inhibitors, producing a hypertensive crisis, and should be used cautiously in cardiovascular disease and hyperthyroidism.

Monitoring

Monitor blood pressure, heart rate and ECG continuously during and after administration.

Counselling the patient

Inform the team that the patient may experience a transient rise in heart rate and blood pressure.
Check for current or recent monoamine oxidase inhibitor use before giving.

Evidence & guidelines

Its use for anaesthesia-related hypotension reflects long-standing established practice and product information.

Reference: OAA (Obstetric Anaesthetists Association) Guidelines; NICE NG121 (Caesarean Section); 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).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways