Nitrous oxide (medication)

Nitrous oxide
	Entonox CD cylinder and giving set
Clinical data
Trade names	Entonox, Nitronox, others
ATC code	N01AX13 (WHO) ;
Pharmacokinetic data
Onset of action	30 seconds
Duration of action	1 minute
Identifiers
	IUPAC name Nitrous oxide;
CAS Number	10024-97-2;
PubChem CID	948;
DrugBank	06690;
ChemSpider	923;
UNII	K50XQU1029;
ChEBI	CHEBI:17045;
ChEMBL	ChEMBL1234579;
Chemical and physical data
Formula	N2O
Molar mass	44.013 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES [N-]=[N+]=O;
	InChI InChI=1S/N2O/c1-2-3; Key:GQPLMRYTRLFLPF-UHFFFAOYSA-N;

Nitrous oxide is an inhaled gas used as a pain medication and together with other medications for anesthesia.^[2] Common uses include during childbirth, following trauma, and as part of end-of-life care.^[2] Onset of effect is typically within half a minute, and the effect lasts for about a minute.^[1]

There are few side effects, other than vomiting, with short-term use.^[1]^[2] With long-term use anemia or numbness may occur.^[2] It should always be given with at least 21% oxygen.^[2] It is not recommended in people with a bowel obstruction or pneumothorax.^[2] Use in the early part of pregnancy is not recommended.^[1] It is possible to continue breastfeeding following use.^[3]

Nitrous oxide was discovered between 1772 and 1793 and used for anesthesia in 1844.^[4] It is on the World Health Organization's List of Essential Medicines.^[5] It often comes as a 50/50 mixture with oxygen.^[1] Devices with a demand valve are available for self-administration.^[6] The setup and maintenance is relatively expensive for developing countries.^[7]^[8]

^ ^a ^b ^c ^d ^e ^f "Anaesthesia UK : Entonox". www.frca.co.uk. 26 January 2009. Archived from the original on 31 October 2007. Retrieved 15 December 2016.
^ ^a ^b ^c ^d ^e ^f World Health Organization (2009). Stuart MC, Kouimtzi M, Hill SR (eds.). WHO Model Formulary 2008. World Health Organization. p. 20. hdl:10665/44053. ISBN 9789241547659.
^ "Nitrous Oxide use while Breastfeeding". Drugs.com. Archived from the original on 21 December 2016. Retrieved 15 December 2016.
^ Myers RL (2007). 100 Most Important Chemical Compounds, The: A Reference Guide: A Reference Guide. ABC-CLIO. p. 198. ISBN 9780313080579. Archived from the original on 2016-12-20.
^ World Health Organization (2021). World Health Organization model list of essential medicines: 22nd list (2021). Geneva: World Health Organization. hdl:10665/345533. WHO/MHP/HPS/EML/2021.02.
^ British national formulary : BNF 69 (69 ed.). British Medical Association. 2015. p. 878. ISBN 9780857111562.
^ Gregory GA, Andropoulos DB (2012). Gregory's Pediatric Anesthesia, With Wiley Desktop Edition. John Wiley & Sons. p. 1148. ISBN 9781444333466. Archived from the original on 2016-12-20.
^ WHO model prescribing information : drugs used in anaesthesia. World Health Organization. 1989. hdl:10665/41014. ISBN 92-4-140101-X.