Chloroprocaine

Local anesthetics
Local anesthetics

Ester local anaesthetic with rapid onset and very short action: plasma pseudocholinesterase breaks it down in seconds, so systemic toxicity is low.

Updated Nov 1, 2026

Also called: Chloroprocaine hydrochloride, 2-Chloroprocaine

Quick facts

Group: Local anesthetics
Target: Voltage-gated sodium channels (Nav)
Used for: Infiltration and peripheral nerve block
Key effects: Hypotension with central blocks
Monitor: Blood pressure · Level of sensory and motor block
ATC: N01BA04

No doses: the clinician sets them by the current guideline.

Mechanism of action

Voltage-gated sodium channels (Nav)Chloroprocaine

There is no structure with chloroprocaine. The figure shows levobupivacaine, an amide local anaesthetic that blocks the same inner pore of the human Nav1.7 sodium channel.

Target in 3D: Voltage-gated sodium channels (Nav). PDB structure 8I5B (RCSB PDB, public domain). View the structure at RCSB PDB

Chloroprocaine is a chlorinated derivative of procaine, an ester of para-aminobenzoic acid. It blocks voltage-gated sodium channels from inside the nerve and stops conduction. In the blood it is hydrolysed very rapidly by plasma pseudocholinesterase, so its acute systemic toxicity is low and its block is short, which suits brief procedures and quick top-ups through an epidural catheter.

Injected near nerves or into the epidural space
Blocks the sodium channel: no conduction
Rapid hydrolysis by plasma pseudocholinesterase
Short block and low systemic toxicity

Indications

Infiltration and peripheral nerve block
Central nerve block, including lumbar and caudal epidural anaesthesia (the preservative-containing forms are not for spinal use)

Adverse effects

Common

Hypotension with central blocks
Back pain after epidural anaesthesia
Early signs of toxicity: restlessness, tinnitus, dizziness, blurred vision, tremor

Contraindications

Hypersensitivity to drugs of the PABA ester group
Spinal (subarachnoid) use of formulations not intended for it

Key interactions

Sulfonamides: Its para-aminobenzoic acid metabolite inhibits their action; it is not used during sulfonamide treatment.
Vasopressors with ergot-type oxytocics (obstetric blocks): Severe, persistent hypertension or stroke.
Other local anaesthetics: Additive toxicity in mixtures.

What is monitored

Blood pressure, heart rate, oxygen saturation and consciousness
Level of sensory and motor block in epidurals
In labour: maternal blood pressure and fetal heart rate

Administration and safety

Aspirate before and during injection and inject slowly in fractions.
This presentation is not for spinal anaesthesia: check that the vial matches the intended route.
Resuscitation equipment and drugs are at hand.
Use caution in liver disease, because the liver makes plasma cholinesterase.

Pregnancy and breastfeeding

Used in obstetric anaesthesia; local anaesthetics cross the placenta, but after a correct paracervical block only traces of a chloroprocaine metabolite were found in cord blood.

Nursing care

Ask about allergy to ester local anaesthetics or PABA, and about sulfonamide treatment.
Explain the temporary loss of sensation and movement in the lower body after an epidural.
Watch for hypotension and early signs of toxicity during the block.
Report back pain after epidural anaesthesia.

Pharmacokinetics

Metabolism: Hydrolysis of the ester bond by plasma pseudocholinesterase to β-diethylaminoethanol and 2-chloro-4-aminobenzoic acid.
Elimination: Kidney, as metabolites.
Half-life: Seconds in plasma; longer in neonates.
Onset and duration: Rapid; the anaesthesia lasts up to about an hour.

Test yourself

Think of the answer, then tap the question to see it.

Why is chloroprocaine's systemic toxicity low?

Plasma pseudocholinesterase hydrolyses it within seconds.

Which antibiotic group does chloroprocaine's metabolite antagonise?

Sulfonamides, through its para-aminobenzoic acid metabolite.

Which allergy contraindicates chloroprocaine?

Hypersensitivity to PABA ester local anaesthetics.

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Connections

← Back to the class: Local anesthetics

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: DailyMed - CHLOROPROCAINE HYDROCHLORIDE injection, solution (DailyMed (U.S. National Library of Medicine), 2025); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).

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Representative model, for educational purposes only.