Penthrox® Europe
Penthrox® Europe

This website is an information resource intended for healthcare professionals only.

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Patients who have been given Penthrox® can find the Patient Information Leaflet (PIL) here.

Report adverse events

If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in the package leaflet. By reporting side effects, you can help provide more information on the safety of medicine.

Mundipharma routinely monitors the safety of all its medicines, including reviewing safety data from clinical studies and collecting reports of adverse events. If you are a patient or are aware of a patient who has experienced an adverse event, overdose or unexpected benefits with one of our products, please also contact Mundipharma by calling +44 (0) 1223 424 211 or by emailing Mundipharma will only use your details to contact you about your adverse event report.

Penthrox is a registered trademark of Medical Developments International Limited and is used under licence. The Mundipharma network of independent associated companies has exclusive rights in 40 European countries, but excluding the UK and Ireland.

Copyright © 2018 Mundipharma International Limited. All rights reserved.


Simple, fast, effective

trauma pain relief enables you to focus on your patient’s injury

Fast onset aids patients

Penthrox® is inhaled, it enters the lungs in the form of a vapour and is rapidly transported into the bloodstream, giving a fast onset of analgesic action.

In the STOP! Study, a randomised, double-blind, placebo-controlled trial, the median time to first pain relief with Penthrox® was just 4 minutes (vs. 10 minutes with placebo)2. Because it works so quickly, Penthrox® can help minimise patients’ suffering, in the emergency room and this may also improve patients’ satisfaction.6


vs 10 minutes placebo2

Works within 6-10 breaths1,2

Median time to onset of meaningful pain relief

morphine sulphate
- mins12
- mins13
- mins13

Penthrox® – the STOP! Study shows fast, effective action11

The STOP! Study was a randomised, double-blind, placebo-controlled, UK trial that investigated the efficacy and safety of Penthrox® for the treatment of acute pain in the emergency department.

The investigators found that Penthrox® significantly reduces pain severity compared to placebo, and concluded:

‘Considering its fast onset of action, ease of use and minimal impact on subsequent treatment choices, methoxyflurane may also lend itself as a bridging agent in the pre-hospital/ED setting until it is possible to administer more powerful analgesia if required.’11

Results of the analysis of VAS Pain Intensity Score (adults ≥18 years)

Adapted from Coffey et al. Adv. Ther 2016.
p<0.0001 overall treatment effect, all time points.
Mean baseline VAS pain score was ~66mm.
Treatment effect was estimated as the average (least squares mean) difference between the Penthrox® treated group and placebo group.

Penthrox® has a well-established safety profile

Penthrox® has been used for over 40 years in Australia and New Zealand, accumulating a total of over 6 million administrations.2,3,53

Historical risk associated with high anaesthetic doses of methoxyflurane

Nephrotoxicity caused by metabolite fluoride, is a dose-related effect associated with high anaesthetic doses3

Analgesic dose Penthrox® significantly lower than anaesthetic dose – at least 6-fold below the upper safety limit3

Methoxyflurane Penthrox® (1 x 3mL bottle) 0.3
Methoxyflurane Upper safety limit ≤2.0
Methoxyflurane Subclinical toxicity 2.5-3.0
Methoxyflurane Clinical toxicity >5.0
MAC minimum alveolar concentration, the concentration required to produce surgical anaesthesia in 50% of healthy patients
MAC-hour determined by multiplying the MAC by the duration of administration of anaesthetic

Adapted from Dayan AD, 20163

Summary of product characteristics (PDF)

The STOP! Study found that majority of adverse events are usually mild and transient, the most common being dizziness and headache.1,2,11

Penthrox® has no clinically relevant effects on vital signs and only a low risk associated with respiratory depression1,14

See more in-depth information
MedDRA System Organ Class Common
≥1/100 to <1/10
≥1/1,000 to <1/100
Metabolism and nutrition disorders Increased appetite
Psychiatric disorders Anxiety
Euphoric mood
Nervous system disorders Amnesia
Peripheral sensory neuropathy
Eye disorders Diplopia
Vascular disorders Hypotension
Respiratory, thoracic and mediastinal disorders Cough
Gastrointestinal disorders Dry mouth
Oral discomfort
Skin and subcutaneous tissue disorders Hyperhidrosis
General disorders and administration site conditions Feeling drunk Fatigue
Feeling abnormal

Other adverse events have been seen but their frequency cannot be estimated, prescribers should consult the SmPC for further details

See more in-depth information

Use as an anaesthetic agent

Who are susceptible to malignant hyperthermia or have a relative who has had malignant hyperthermia

Altered level of consciousness due to any cause including head injury, drugs, or alcohol

Who have a history of hypersensitivity to Penthrox® or other fluorinated anaesthetics

Those who have a history of liver damage after previous Penthrox® use or halogenated hydrocarbon anaesthetics

Those with clinically significant renal impairment

Those demonstrating clinically evident cardiovascular instability

Those demonstrating clinically evident respiratory depression