# Norepinephrine (Noradrenaline): veterinary dose and monograph

> Norepinephrine (Noradrenaline) is a veterinary cardiovascular drug. A potent endogenous catecholamine VASOPRESSOR (strong α1 with some β1 activity) — the first-line pressor for FLUID-REFRACTORY VASODILATORY (SEPTIC) SHOCK and other severe hypotension, given ONLY as an IV constant-rate infusion… Indications include fluid-refractory vasodilatory/septic shock — first-line vasopressor; severe hypotension (anaphylactic/anaesthetic/critical illness) unresponsive to fluids; maintenance of mean arterial/perfusion pressure in ICU patients. This monograph lists 3 reference doses for dogs and cats, each with route, frequency and source.

Source: https://vetmasterji.com/drugs/norepinephrine · Last reviewed: 2026-10-01

## At a glance

- **Drug class:** Cardiovascular
- **Also known as:** Noradrenaline, Levophed, Adrenor
- **Species with doses:** Dogs and Cats
- **Routes:** IV
- **Last reviewed:** 1 October 2026

## Indications

- Fluid-refractory vasodilatory/septic shock — first-line vasopressor
- Severe hypotension (anaphylactic/anaesthetic/critical illness) unresponsive to fluids
- Maintenance of mean arterial/perfusion pressure in ICU patients

## Norepinephrine (Noradrenaline) dose by species

Doses are per administration unless stated. mg/kg doses scale with body weight; per-animal, per-quarter and infusion-rate doses are shown as the reference writes them.

### Dogs

*Norepinephrine (Noradrenaline) doses for dogs*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Persistent hypotension after adequate fluid replacement — starting rate | 0.05–0.1 µg/kg/min | IV | CRI; titrate to effect (most recommend a maximum of 1–2 µg/kg/min) | — |
| Isoflurane-induced hypotension | 0.1–2 µg/kg/min | IV | CRI, titrated to blood pressure | — |

- Persistent hypotension after adequate fluid replacement — starting rate: Plumb’s 10e p.944 (dogs/cats, extra-label): profound hypotension persisting after adequate fluid volume replacement — initial 0.05–0.1 µg/kg/minute IV CRI, titrated up to the desired effect; most recommend a maximum of 1–2 µg/kg/minute. Can be combined with dopamine, dobutamine or vasopressin. Papich 5e has no norepinephrine monograph.
- Isoflurane-induced hypotension: Plumb’s 10e p.944 (extra-label): in 12 healthy beagles the average effective dose was 0.44 µg/kg/minute IV CRI, range 0.1–2 µg/kg/minute.

### Cats

*Norepinephrine (Noradrenaline) doses for cats*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Persistent hypotension after adequate fluid replacement — starting rate | 0.05–0.1 µg/kg/min | IV | CRI; titrate to effect (most recommend a maximum of 1–2 µg/kg/min) | — |

- Persistent hypotension after adequate fluid replacement — starting rate: Plumb’s 10e p.944 (dogs/cats, extra-label): initial 0.05–0.1 µg/kg/minute IV CRI after adequate fluid volume replacement, titrated to effect; most recommend a maximum of 1–2 µg/kg/minute. (The isoflurane-hypotension figures come from a dog study.) Papich 5e has no norepinephrine monograph.

## Contraindications

Uncorrected hypovolaemia (resuscitate volume first). Severe uncorrected tachyarrhythmia. Extravasation risk (use a reliable/central line). Never as a bolus or undiluted. Known hypersensitivity (sulphite-containing formulations). MAO inhibitors (potentiated pressor effect).

## Adverse effects

- Excessive vasoconstriction → organ/peripheral ischaemia at high rates
- Reflex bradycardia or tachyarrhythmia
- Severe tissue necrosis if extravasated
- Increased myocardial oxygen demand

## Drug interactions

- MAO inhibitors / tricyclics: greatly potentiated, prolonged pressor effect — reduce dose drastically
- Alpha-blockers: antagonise the pressor effect
- Halothane/some anaesthetics: increased arrhythmogenicity
- Incompatible with alkaline solutions (bicarbonate) in the line

## Pregnancy and lactation

Used in critical maternal hypotension when needed; maternal perfusion prioritised. Limited specific data.

## Monitoring

- Continuous (ideally invasive) blood pressure — titrate to target MAP
- Perfusion markers (lactate, urine output, extremities) — avoid over-vasoconstriction
- IV catheter site (extravasation — prefer central line); ECG
- Volume status (resuscitate before/with pressor)

## Toxicity and overdose

Excessive infusion causes severe vasoconstriction with peripheral/organ ischaemia (limbs, gut, kidneys), reflex bradycardia or arrhythmia, hypertension and increased myocardial oxygen demand/ischaemia. Extravasation produces local tissue necrosis. Effects reverse quickly when the rate is reduced (short half-life).

Management: Reduce or stop the infusion (rapid resolution). For severe vasoconstriction/extravasation, phentolamine (an alpha-blocker) can be infiltrated locally at the extravasation site or given systemically. Treat arrhythmias; continuous ECG/BP monitoring. Ensure the patient is not simply hypovolaemic.

## Clinical pearls

- The first-line vasopressor for fluid-refractory vasodilatory/septic shock — raises perfusion pressure (α1) while supporting output (β1)
- CRI only, in mcg/kg/min, via a pump and ideally a CENTRAL line — never bolus; and fix hypovolaemia first (pressors don't replace volume)
- Beware extravasation (tissue necrosis) — phentolamine infiltration is the rescue; a central line is safer
- Short half-life means rapid titratability — reduce the rate and the effect fades within minutes

## Mechanism of action

A catecholamine that potently stimulates α1-adrenergic receptors (arterial and venous vasoconstriction → increased systemic vascular resistance and mean arterial pressure) with moderate β1-adrenergic activity (increased myocardial contractility/output) and minimal β2 effect. This raises perfusion pressure in vasodilatory shock while largely maintaining cardiac output — the rationale for its first-line role. Very short plasma half-life allows minute-to-minute titration.

## Formulations and products

- Injection 1 mg/mL (2 mg/2 mL ampoule) — dilute for CRI
- Levophed / Adrenor — 1 mg/mL (2 mg/2 mL) ampoule, Injection (CRI) (human-label)

## Storage

Ampoules: 15–30 °C, protect from light (discard if discoloured/brown — oxidation). Dilute for infusion; use promptly. Central line preferred.

## Before you use this dose

> **Caution:** Reference doses for veterinary professionals. Confirm the dose against the product label, the patient’s condition, current guidance and local regulations before use; the attending veterinarian remains responsible for every clinical decision.

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## Frequently asked questions

### What is the dose of Norepinephrine (Noradrenaline) for dogs?

Reference doses for Norepinephrine (Noradrenaline) in dogs: 0.05–0.1 µg/kg/min IV CRI; titrate to effect (most recommend a maximum of 1–2 µg/kg/min) (Persistent hypotension after adequate fluid replacement — starting rate); 0.1–2 µg/kg/min IV CRI, titrated to blood pressure (Isoflurane-induced hypotension). Confirm against the label and the patient before use.

### What is the dose of Norepinephrine (Noradrenaline) for cats?

Reference doses for Norepinephrine (Noradrenaline) in cats: 0.05–0.1 µg/kg/min IV CRI; titrate to effect (most recommend a maximum of 1–2 µg/kg/min) (Persistent hypotension after adequate fluid replacement — starting rate). Confirm against the label and the patient before use.

### When should Norepinephrine (Noradrenaline) not be used?

Uncorrected hypovolaemia (resuscitate volume first). Severe uncorrected tachyarrhythmia. Extravasation risk (use a reliable/central line). Never as a bolus or undiluted. Known hypersensitivity (sulphite-containing formulations). MAO inhibitors (potentiated pressor effect).

### What are the side effects of Norepinephrine (Noradrenaline) in animals?

Excessive vasoconstriction → organ/peripheral ischaemia at high rates; Reflex bradycardia or tachyarrhythmia; Severe tissue necrosis if extravasated; Increased myocardial oxygen demand.

## Sources

- Plumb's Veterinary Drug Handbook
- Merck Veterinary Manual, 11th edition
- Papich, Papich Handbook of Veterinary Drugs, 5th edition

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VetMasterJi is a clinical decision-support and education platform for veterinary professionals and students. It does not provide veterinary advice, diagnosis or treatment for specific animals. All drug doses, calculators and differentials are references that must be independently verified before clinical use; the attending registered veterinarian remains solely responsible for every clinical decision.