Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • General
  • Published:

Inhaled methoxyflurane (Penthrox) administration in dentistry as an alternative to nitrous oxide sedation: a review and feasibility study

Abstract

Methoxyflurane (MOF) as an agent for dental sedation has been used safely in Australasia for decades. The drug is now licensed for relief of pain associated with trauma and is being used during several medical outpatient procedures in the stead of traditional intravenous agents for sedation in the UK. Our aim was to analyse the safety and feasibility of the introduction of MOF as a drug for dental sedation in the UK community setting and assess its environmental impact. A literature review was conducted for available studies and a research audit of medical histories of patients that received nitrous oxide sedation in the previous year was carried out to assess suitability for MOF administration. The published literature shows MOF to be a safe drug for administration in the dental environment and local patients receiving nitrous oxide sedation are medically suitable for MOF administration. The advantages of considering MOF sedation are its environmental benefit and patient acceptability.

Key points

  • Gives knowledge on the potential for new sedative agents.

  • Provides knowledge on nitrous oxide contribution to environmental pollution.

  • Refreshes knowledge on sedation best practice.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1

Similar content being viewed by others

References

  1. Mazze R I. Methoxyflurane revisited: tale of an anesthetic from cradle to grave. Anaesthesiology 2006; 105: 843-846.

  2. Electronic medicines compendium. Penthrox 99.9%, 3 ml inhalation vapour, liquid. Available at https://www.medicines.org.uk/emc/medicine/31391#gref (accessed September 2022).

  3. Abdullah W A, Sheta S A, Nooh N S. Inhaled methoxyflurane (Penthrox) sedation for third molar extraction: a comparison to nitrous oxide sedation. Aust Dent J 2011; 56: 296-301.

  4. Roo Dental. Sedation. Available at http://roodental.com.au/services/sedation/ (accessed September 2022).

  5. Teoh L, Mariona R J, Stewart K, McCullough M J. A survey of prescribing practices by general dentists in Australia. BMC Oral Health 2019; 19: 193.

  6. FADC Dental Group. Nervous Patients. Available at https://www.fadc.com.au/for-nervous-patients (accessed September 2022).

  7. Tomlin P J. Methoxyflurane. Br J Anaesth 1965; 37: 706-709.

  8. Unkles R D, Lawson J I. Methoxyflurane in Dental Anaesthesia: A Blind Trial. Br J Anaesth 1965; 37: 422-427.

  9. Allen G D, Anderson M W, Hall R, Herrman J. Methoxyflurane analgesia for dental patients. Anesth Prog 1972; 19: 13.

  10. Ikeda S. The Reincarnation of Methoxyflurane. J Anesth Hist 2020; 6: 79-83.

  11. Grindlay J, Babl F E. Review article: Efficacy and safety of methoxyflurane analgesia in the emergency department and prehospital setting. Emerg Med Australas 2009; 21: 4-11.

  12. Jephcott C, Grummet J, Nguyen N, Spruyt O. A review of the safety and efficacy of inhaled methoxyflurane as an analgesic for outpatient procedures. Br J Anaesth 2018; 120: 1040-1048.

  13. Forrest M, Porter K, van der Velde J. Methoxyflurane (Penthrox) - a case series of use in the prehospital setting. J Paramed Pract 2019; 11: 54-60.

  14. Nguyen N, Toscano L, Lawrence M et al. Patient-controlled analgesia with inhaled methoxyflurane versus conventional endoscopist-provided sedation for colonoscopy: a randomized multicentre trial. Gastrointest Endosc 2013; 78: 892-901.

  15. Gaskell A L, Jephcott C G, Smithells J R, Sleigh J W. Self-administered methoxyflurane for procedural analgesia: experience in a tertiary Australasian centre. Anaesthesia 2016; 71: 417-423.

  16. Australian and New Zealand College of Anaesthetists. PG09(G) Guideline on procedural sedation. 2023. Available at https://www.anzca.edu.au/getattachment/c64aef58-e188-494a-b471-3c07b7149f0c/PG09(G)-Guideline-on-sedation-and-or-analgesia-for-diagnostic-and-interventional-procedures (accessed September 2023).

  17. Dental Board of Australia. Registration Standard: Endorsement for Conscious Sedation. 2015. Available at https://www.dentalboard.gov.au/Registration-Standards.aspx (accessed May 2023).

  18. University of Syndey. Graduate Diploma in Clinical Dentistry (Conscious Sedation and Pain Control). Available at https://www.sydney.edu.au/courses/courses/pc/graduate-diploma-in-clinical-dentistry-conscious-sedation-and-pain-control.html (accessed May 2023).

  19. Dental Board of Australia. Statistics: Registrant Data 2023. 2023. Available at https://www.dentalboard.gov.au/about-the-board/statistics.aspx (accessed May 2023).

  20. Franklin M, Elford J, Hall J, Porter K. Administration of Methoxyflurane (Penthrox) as a Pre-Hospital Analgesic by Specialist Police Officers; A Retrospective Audit of Patient Report Forms. 2020. Available at https://fphc.rcsed.ac.uk/media/2900/administration-of-methoxyflurane-penthrox-as-a-pre-hospital-analgesic-by-specialist-police-officers-a-retrospective-audit-of-patient-report-forms.pdf (accessed December 2023).

  21. Williams O D, Pluck G. The use of methoxyflurane (Penthrox) for procedural analgesia in the emergency department and pre-hospital environment. Trauma 2019; 22: 85-93.

  22. Oxer H F. Effects of Penthrox (methoxyflurane) as an analgesic on cardiovascular and respiratory functions in the pre-hospital setting. J Mil Veterans Health 2016 24: 14-20.

  23. Klein N C, Jeffries G H. Hepatotoxicity After Methoxyflurane Administration. JAMA 1966; 197: 1037-1039.

  24. O'Rourke K M, McMaster S, Lust K M. A case of hepatitis attributable to repeated exposure to methoxyflurane during its use for procedural analgesia. Med J Aust 2011; 194: 423-424.

  25. Therapeutic Goods Administration. Database of Adverse Event Notifications - medicines. Available at https://apps.tga.gov.au/Prod/daen/daen-entry.aspx (accessed September 2022).

  26. Mazze R I, Shue G L, Jackson S H. Renal dysfunction associated with methoxyflurane anaesthesia. A randomized, prospective clinical evaluation. JAMA 1971; 216: 278-288.

  27. Dayan A D. Analgesic use of inhaled methoxyflurane: Evaluation of its potential nephrotoxicity. Hum Exp Toxicol 2015; 35: 91-100.

  28. Coffey F, Wright J, Hartshorn S et al. STOP!: a randomised, double-blind, placebo-controlled study of the efficacy and safety of methoxyflurane for the treatment of acute pain. Emerg Med J 2014; 31: 613-618.

  29. Jacobs I G. Health Effects of Patients Given Methoxyflurane in the Pre-Hospital Setting: A Data Linkage Study. Open Emerg Med J 2010; 3: 7-13.

  30. Frangos J, Mikkonen A, Down C. Derivation of an occupational exposure limit for an inhalation analgesic methoxyflurane (Penthrox). Regul Toxicol Pharmacol 2016; 80: 210-225.

  31. Allison S J, Docherty P D, Pons D, Chase J G. Methoxyflurane toxicity: historical determination and lessons for modern patient and occupational exposure. N Z Med J 2021; 134: 76-90.

  32. Hass S A, Andersen S T, Sulbaek Andersen M P, Nielsen O J. Atmospheric Chemistry of Methoxyflurane (CH3OCF2CHCl2): Kinetics of the gas-phase reactions with OH radicals, Cl atoms and O3. Chem Phys Lett 2019; 722: 119-123.

  33. Myhre G, Shindell D, Bréon F-M et al. Anthropogenic and Natural Radiative Forcing. In Stocker T F, Qin D, Plattner G-K, Tignor M, Allen S K, Boschung J, Nauels A, Xia Y, Bex V, Midgley P M (eds) Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge: Cambridge University Press, 2013.

  34. Elliott K J, Pierce J M. Twelve-year trend in nitrous oxide use at a tertiary institution: striving for a net zero NHS. Anaesthesia 2021; 76: 1667-1668.

  35. Sedation, Analgesia and Anxiety management for Dentistry. Reducing the Climate Impact of Nitrous Oxide Use in Dentistry. DSTG and SAAD Position Statement. 2021.

  36. Air Liquide Gas Encyclopedia. Nitrous oxide. Available at (accessed May 2023).

  37. Intercollegiate Advisory Committee for Sedation in Dentistry. Standards for Conscious Sedation in the Provision of Dental Care (V1.1). 2020. Available at https://www.saad.org.uk/IACSD%202020.pdf (accessed May 2023).

Download references

Author information

Authors and Affiliations

Authors

Contributions

DI and DJ conceived and developed the study; DI collected data; DI, DJ and KB analysed data; DI produced the manuscript; DI, DJ and KB revised the manuscript.

Corresponding author

Correspondence to Diana Inkster.

Ethics declarations

The authors declare no conflicts of interest.

Caldicott and Health Board approval was obtained for logbook data collection and analysis. Medical information was gleaned retrospectively from electronic dental and medical records.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Inkster, D., Jones, D. & Barker, K. Inhaled methoxyflurane (Penthrox) administration in dentistry as an alternative to nitrous oxide sedation: a review and feasibility study. Br Dent J 236, 124–129 (2024). https://doi.org/10.1038/s41415-023-6724-6

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41415-023-6724-6

Search

Quick links