[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Local anesthetics](https://durgical.com/en/pharmacology/classes/local-anesthetics/) › Prilocaine

# Prilocaine

## Local anesthetics?

Local anesthetics

Intermediate-acting amide local anaesthetic, mostly dental and in a skin cream with lidocaine. Its o-toluidine metabolite causes methaemoglobinaemia.

Updated Nov 1, 2026

Also called: Prilocaine hydrochloride

## Quick facts

**Group**
[Local anesthetics](https://durgical.com/en/pharmacology/classes/local-anesthetics/)

**Target**
Voltage-gated sodium channels (Nav)

**Used for**
Dental infiltration · Intravenous regional anaesthesia

**Key effects**
Skin cream · Abnormal sensation at the treated area

**Monitor**
Skin and lip colour and pulse oximetry

**ATC**
N01BB04

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

On this page

- The basics Mechanism of action
- Indications
- Adverse effects
- Pharmacokinetics
- Memory aid

- Safety Contraindications
- Key interactions
- What is monitored
- Administration and safety
- Pregnancy and breastfeeding
- Nursing care

- Study Test yourself

- Connections Connections

## Mechanism of action

⇅**Voltage-gated sodium channels (Nav)**Prilocaine

ⓘ There is no structure with prilocaine. The figure shows levobupivacaine, another amide local anaesthetic, in the 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](https://www.rcsb.org/structure/8I5B) · Drag to rotate · pinch to zoom

Prilocaine is an amide local anaesthetic: its un-ionised form crosses the nerve membrane and, from inside, blocks the voltage-gated sodium channel so that no action potential travels and pain is not felt. It causes little vasodilation, so it can be used without a vasoconstrictor, and its large volume of distribution lowers its CNS toxicity. Unlike other amides, it is first hydrolysed to o-toluidine, which oxidises haemoglobin to methaemoglobin.

- Crosses the nerve membrane in its un-ionised form
- Blocks the sodium channel from inside
- No action potential: local loss of pain
- Metabolism to o-toluidine can produce methaemoglobin

## Indications

- Dental infiltration and nerve-block anaesthesia
- Topical anaesthesia of intact skin with lidocaine (eutectic cream) before venepuncture, cannulation or superficial procedures, and of genital mucosa for minor surgery
- Intravenous regional anaesthesia, where it is suitable because of its low CNS toxicity

## Adverse effects

### Common

- Skin cream: transient paleness, then redness or swelling at the site
- Abnormal sensation at the treated area
- Signs of systemic toxicity with high levels: perioral numbness, dizziness, tinnitus

### Serious (rare, important)

- Methaemoglobinaemia: grey or blue skin, headache, fast heart rate, breathlessness, fatigue; higher risk in G6PD deficiency, congenital methaemoglobinaemia and infants under six months
- Local anaesthetic systemic toxicity: seizures, arrhythmias, cardiovascular collapse
- Severe eye irritation and corneal injury if cream reaches the eye; ototoxicity if it passes into the middle ear

## Contraindications

- Hypersensitivity to amide-type local anaesthetics or to any component

## Key interactions

**Other methaemoglobin-forming drugs (nitrates and nitrites such as nitric oxide and nitroglycerin, dapsone, sulfonamides, nitrofurantoin, acetaminophen, metoclopramide, quinine)**
Higher risk of methaemoglobinaemia.

**Other local anaesthetics**
Additive systemic toxicity; total amounts from all products are added up.

## What is monitored

- Skin and lip colour and pulse oximetry; methaemoglobin level if cyanosis appears
- Consciousness and early signs of toxicity after injection
- In infants and children: treated area and application time

## Administration and safety

- The cream goes on intact skin under an occlusive dressing, ahead of the procedure; not on open wounds or near the eyes.
- It is not used where it could pass the eardrum into the middle ear.
- Dental injection: aspirate before injecting and inject slowly.
- Amounts from different local anaesthetic products are added together.

## Pregnancy and breastfeeding

Animal studies with lidocaine and prilocaine showed no fetal harm; it is not contraindicated in labour. Lidocaine, and probably prilocaine, pass into breast milk.

## Nursing care

- Ask about G6PD deficiency, methaemoglobinaemia and methaemoglobin-forming drugs before use.
- Check the skin after removing the cream and watch infants closely.
- Teach the signs of methaemoglobinaemia and to seek care at once if they appear.
- Protect the numb area (eye, mouth, skin) from injury until sensation returns.

## Pharmacokinetics

**Absorption**
Systemic absorption depends on site, area and time of contact; from the skin cream it grows with area and application time.

**Distribution**
Large volume of distribution.

**Metabolism**
Hydrolysed (liver and kidney) to o-toluidine metabolites.

**Half-life**
Prolonged in liver or kidney dysfunction.

## Memory aid

PRILOcaine → «PRetty bLue»: o-toluidine turns blood brown and lips blue; the antidote is methylene blue.

## Test yourself

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

## Which metabolite of prilocaine causes methaemoglobinaemia?

o-Toluidine, formed by hydrolysis of prilocaine.

## Which patients are at highest risk of methaemoglobinaemia from prilocaine?

Patients with G6PD deficiency or congenital methaemoglobinaemia, those with heart or lung compromise, and infants under six months.

## How is prilocaine-induced methaemoglobinaemia treated if needed?

Intravenous methylene blue, together with oxygen and supportive care.

## Why is a eutectic lidocaine–prilocaine cream able to anaesthetise intact skin?

The mixture melts below room temperature into an oil that penetrates intact skin under an occlusive dressing.

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[More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology)

## Connections

## Related drugs 3

- [Lidocaine](https://durgical.com/en/pharmacology/lidocaine/)
- [Mepivacaine](https://durgical.com/en/pharmacology/mepivacaine/)
- [Articaine](https://durgical.com/en/pharmacology/articaine/)

[← Back to the class: Local anesthetics](https://durgical.com/en/pharmacology/classes/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 - LIDOCAINE AND PRILOCAINE cream](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=833cd52c-6470-49c4-937f-1393971f4db9) (DailyMed (U.S. National Library of Medicine), 2026); [Lidocaine and Prilocaine Topical: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a625032.html) (MedlinePlus (U.S. National Library of Medicine), 2025); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=N01BB04) (WHO Collaborating Centre for Drug Statistics Methodology, 2026).

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Representative model, for educational purposes only.

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