Not Yet RecruitingPhase 3

Use of the Methoxyflurane as Pain-killer in the Prehospital Management of Acute Myocardial Infarction

France700 participantsStarted 2026-06

Plain-language summary

* Chest pain is the main symptom of acute myocardial infarction. A precocious analgesic treatment is justified by patient's comfort and unfavorable hemodynamic consequences of persistent pain. Morphine is the painkiller historically prescribed in this situation. Morphine has never been evaluated vs placebo and is strongly suspected to decrease oral anti-platelet efficacy. Then, morphine has been downgraded, in the 2017 European guidelines (European Society of Cardiology - ESC) from I to IIa. To find alternative treatment is required. * The methoxyflurane is an anesthetic gas used in emergency setting for about twenty years. It is now commonly used in France. Its analgesic properties have been demonstrated. Its main advantages are its maneuverability as it is delivered by inhalation, i.e. without (before) any venous access and self-administered by the patient. Tolerability is good. It could be an excellent alternative to morphine.

Who can participate

Age range

18 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Patient age ≥ 18 years * Patient managed in pre-hospital setting for a ST elevation myocardial infarction (STEMI) : Chest pain \< 12 hours with moderate to severe pain (VAS \> 6/10) or STEMI on ECG according to 2017 ESC guidelines Exclusion Criteria: * Previous analgesic treatment for this episode of chest pain * Hypersensitivity to morphine, methoxyflurane, any fluorinated anesthetic or any of the excipients listed in SmPC, * Decompensated respiratory failure (in the absence of artificial ventilation), * Severe hepatocellular insufficiency (with encephalopathy), * Acute head trauma and intracranial hypertension in the absence of controlled ventilation, * Uncontrolled epilepsy, * Treatment with buprenorphine, nalbuphine and pentazocine, naltrexone, nalmefene or sodium oxybate, * Breastfeeding, in case of initiation or continuation after birth of a long-term treatment. * Known malignant hyperthermia or genetic predisposition of the patient. * History of serious adverse effects of the patient or his family after administration of inhaled anesthetics. * History of signs of liver damage after use of methoxyflurane or after anesthesia with a halogenated hydrocarbon. * Clinically significant renal impairment. * Known renal failure with creatinine clearance below 30 ml/min or undergoing extracorporeal renal replacement therapy. * Altered level of consciousness due to any cause, including head trauma, drug or alcohol use. * Clinical evidence of cardiovascular…

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1This trial is testing methoxyflurane as a painkiller during a heart attack before reaching the hospital — given that I've had a STEMI, is inhaled methoxyflurane something that could realistically be part of my emergency care plan, and what are the known risks of using it in that high-pressure situation?
2The trial is comparing methoxyflurane to morphine for pain relief during a STEMI — can you explain what my current standard of care would look like, and whether morphine or another opioid is what I'd typically receive right now if methoxyflurane isn't available?
3Since this is a Phase 3 trial that hasn't started recruiting yet, what does that mean for how soon it might be available, and is there any earlier-phase data on methoxyflurane in cardiac emergencies that you've seen that would help us understand its safety profile?
4The trial focuses on the prehospital setting — meaning from when symptoms start until I reach the hospital — so would participating in something like this require me or people around me to do anything differently in an emergency, and how realistic is that?
5If I were ever to discuss enrolling in a trial like this, what would it mean for my other heart attack treatments, and would joining this study affect the speed or approach of my standard STEMI care like getting a stent?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Demonstrate that methoxyflurane self-administered by the patient is at least as efficient in achieving pain relief that morphine

Timeframe: at 30 minutes

Trial details

NCT IDNCT07445737

SponsorAssistance Publique - Hôpitaux de Paris

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2029-06

Contact for this trial

Frederic LAPOSTOLLE, MD,PHD

01 48 96 44 54 frederic.lapostolle@aphp.fr

View on ClinicalTrials.gov More STEMI - ST Elevation Myocardial Infarction trials