[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Topical antibacterials](https://durgical.com/en/pharmacology/classes/topical-antibacterials/) › Retapamulin

# Retapamulin

## Topical antibacterials?

Topical antibacterials

A topical pleuromutilin antibiotic ointment for impetigo caused by Staphylococcus aureus or Streptococcus pyogenes; discontinued in the US.

Updated Nov 1, 2026

## Quick facts

**Group**
[Topical antibacterials](https://durgical.com/en/pharmacology/classes/topical-antibacterials/)

**Target**
Bacterial 50S ribosomal subunit (peptidyl transferase centre)

**Used for**
Impetigo caused

**Key effects**
Irritation · Headache · Diarrhoea

**Monitor**
Healing of the impetigo lesions

**ATC**
D06AX13

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

◆**Bacterial 50S ribosomal subunit (peptidyl transferase centre)**Retapamulin

ⓘ The figure shows retapamulin bound to the large (50S) ribosomal subunit of the bacterium Deinococcus radiodurans; it is not a human protein.

**Target in 3D:** Bacterial 50S ribosomal subunit (peptidyl transferase centre). PDB structure 2OGO (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/2OGO) · Drag to rotate · pinch to zoom

Retapamulin is a semisynthetic pleuromutilin, from a compound made by Pleurotus fungi. It binds a unique site on the bacterial 50S ribosomal subunit and blocks protein synthesis. It is active against gram-positive skin bacteria such as Staphylococcus aureus and Streptococcus pyogenes.

- Ointment reaches bacteria in impetigo crusts
- Retapamulin binds a unique site on the 50S ribosome
- Bacterial protein synthesis stops
- Impetigo lesions heal

## Indications

- Impetigo caused by susceptible Staphylococcus aureus or Streptococcus pyogenes, in adults and children [Impetigo →](https://durgical.com/en/conditions/impetigo/)

## Adverse effects

### Common

- Irritation, burning, redness or itching where applied
- Headache
- Diarrhoea

### Serious (rare, important)

- Blistering, swelling or oozing at the site (severe irritation or allergy)

## Contraindications

- Hypersensitivity to retapamulin

## Key interactions

**Strong CYP3A4 inhibitors**
Could raise the small absorbed amount; caution, especially in young children or on large areas of broken skin.

## What is monitored

- Healing of the impetigo lesions
- Irritation or allergic reaction at the site

## Administration and safety

- A thin layer is applied to the infected skin only, with a clean cotton swab.
- The area may be covered with a bandage or gauze, especially in young children.
- Kept out of the eyes, nose, mouth and genital mucosa, and not swallowed.

## Pregnancy and breastfeeding

Little is absorbed from the skin; pregnancy and breastfeeding are mentioned to the clinician.

## Nursing care

- Teach hand-washing after application and keeping the child's lesions covered to limit spread.
- Teach to report lesions that are spreading or not healing, or fever.
- Teach to report blistering, swelling or oozing at the site.

## Pharmacokinetics

**Absorption**
Applied to the skin; absorption is low, but higher in children and on broken skin

**Metabolism**
CYP3A4 substrate

## Memory aid

RETApamulin: RETAins impetigo bacteria at the 50S — from a mushroom (Pleurotus).

## Test yourself

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

## Which bacterial structure does retapamulin bind?

A unique site on the 50S ribosomal subunit, blocking protein synthesis.

## Which skin infection is retapamulin used for?

Impetigo caused by S. aureus or S. pyogenes.

## From what natural source do pleuromutilins come?

Fungi of the genus Pleurotus.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/retapamulin/)

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

## Connections

## Related drugs 2

- [Mupirocin](https://durgical.com/en/pharmacology/mupirocin/)
- [Bacitracin](https://durgical.com/en/pharmacology/bacitracin/)

## Related conditions 1

- [Impetigo](https://durgical.com/en/conditions/impetigo/)

[← Back to the class: Topical antibacterials](https://durgical.com/en/pharmacology/classes/topical-antibacterials/)

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

Sources: [Retapamulin: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a607049.html) (MedlinePlus (U.S. National Library of Medicine), 2025); [RCSB PDB - 2OGO: The crystal structure of the large ribosomal subunit from Deinococcus radiodurans complexed with the pleuromutilin derivative retapamulin (SB-275833)](https://www.rcsb.org/structure/2OGO) (RCSB Protein Data Bank, 2007); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=D06AX13) (WHO Collaborating Centre for Drug Statistics Methodology, 2026).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/pharmacology/retapamulin/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/retapamulin/