STEMI - ST Elevation Myocardial InfarctionPhase 3MAMINCT07445737
Use of the Methoxyflurane as Pain-killer in the Prehospital Management of Acute Myocardial Infarction
A Phase 3 study testing Methoxyflurane and Morphine in people with STEMI - ST Elevation Myocardial Infarction, run by Assistance Publique - Hôpitaux de Paris at 1 site in France.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- STEMI - ST Elevation Myocardial Infarction
- What is being tested?
- Methoxyflurane and Morphine
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 700 participants
- Where
- 1 siteFrance
- Study dates
- Jun 2026to Jun 2029
- Phase
- Phase 3
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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
Who cannot join
- 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,
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- 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 instability (PAS <90 mm Hg).
- Clinical evidence of respiratory depression.
- Incapacity to self-assess pain intensity
- Incapacity to methoxyflurane self-administration
- Known pregnancy, breastfeeding, minors or incapacity (curatorship or guardianship)
- Participation in another interventional study involving human participants or being in the exclusion period at the end of a previous study involving human participants
- Absence of a Social Security
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
France1 site
Hôpital Avicenne
Bobigny, 93000
Frederic LAPOSTOLLE, MD PhD, 01 48 96 44 54 ext. +33, frederic.lapostolle@aphp.fr
About this study
- 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.
- Being tested
- Methoxyflurane, Morphine
- Keywords
- chest pain, morphine, methoxyflurane
- Medical subject headings
- ST Elevation Myocardial Infarction, Chest Pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
MethoxyfluraneDrug
Also called Penthrox®
Patient's self-administration of methoxyflurane (Penthrox®) with dedicated inhaler Initial dose: 3 mL (1 vial). A second 3 mL dose can be used. Treatment: from inclusion to hospital arrival.
MorphineDrug
Morphine intra-venous infusion: 3 mg bolus repeated every 5 minutes until obtaining VAS ≤ 3. Treatment: from inclusion to hospital arrival
| Study group | Role | What they receive |
|---|---|---|
| Morphine | Active comparator | Morphine intra-venous infusion: 3 mg bolus repeated every 5 minutes until obtaining VAS ≤ 3 Receives: Drug: Morphine |
| Methoxyflurane | Experimental | Patient's self-administration of methoxyflurane (Penthrox®) with dedicated inhaler Initial dose: 3 mL (1 vial). A second 3 mL dose can be used. Receives: Drug: Methoxyflurane |
What is being measured
The primary outcome is the main question the study is designed to answer.
Demonstrate that methoxyflurane self-administered by the patient is at least as efficient in achieving pain relief that morphine
To demonstrate that methoxyflurane self-administered by the patient suffering chest pain related to an acute myocardial infarction is at least as efficient in achieving pain relief that morphine with better tolerance (achieving pain relief, i.e. pain intensity score on visual analogic scale (VAS) ≤ 3 at 30 minutes)
Measured: at 30 minutes
Secondary outcomes (9)
Compare the impact of the treatments on heart rate
Impact of the treatments on cardiovascular system: heart rate (data collected every 5 minutes until to 30 minutes after randomisation and at hospital arrival)
Measured: at 30 minutes
Compare the impact of the treatments on arterial blood pressure
Impact of the treatments on cardiovascular system: arterial blood pressure (data collected every 5 minutes until to 30 minutes after randomisation and at hospital arrival)
Measured: at 30 minutes
Compare the impact of the treatments on pulse oximetry
Impact of the treatments on cardiovascular system: pulse oximetry (data collected every 5 minutes until to 30 minutes after randomisation and at hospital arrival)
Measured: at 30 minutes
Compare the impact of the treatments on ECG
Impact of the treatments on cardiovascular system: ECG changes before discharge from the ambulance
Measured: at 30 minutes
Compare tolerance of the treatments on respiratory depression
Tolerance of the treatments: respiratory depression: respiratory rate < 10 cycles per minutes (data collected every 5 minutes until to 30 minutes after randomisation and at hospital arrival)
Measured: at 30 minutes
Compare tolerance of the treatments on sedation
Tolerance of the treatments: sedation: Richmond Agitation Sedation Scale (RASS) ≥ 2 or ≤ -2 (data collected every 5 minutes until to 30 minutes after randomisation and at hospital arrival)
Measured: at 30 minutes
Compare tolerance of the treatments on dizziness, pruritus, nausea, vomiting, headache
Tolerance of the treatments: dizziness, pruritus, nausea, vomiting, headache (data collected every 5 minutes until to 30 minutes after randomisation and at hospital arrival)
Measured: at 30 minutes
Compare the impact of the treatments on pain relief
Time before achieving pain relief, i.e. time to reach initial pain divided by two (initial VAS / 2)
Measured: From randomization until the first documented pain divided by two, assessed up to 30 minutes
Compare the impact of the treatments on pain relief
Time before achieving pain relief, i.e. time between randomisation and pain intensity score on VAS ≤ 3
Measured: From randomization until the first documented pain relief, assessed up to 30 minutes
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Mar 2026
- Study startJun 2026 (estimated)
- Primary completionJun 2029 (estimated)
- Study completionJun 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for STEMI - ST Elevation Myocardial InfarctionStudies of the same condition, open and under way.
- More trials run by Assistance Publique - Hôpitaux de ParisThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 700 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Assistance Publique - Hôpitaux de Paris
- Sponsor type
- University, hospital or other
- Collaborators
- Medical Developments International Limited
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07445737
- Sponsor's protocol ID
- APHP180610
- Other IDs
- 2025-523349-86-00, 2025
- Acronym
- MAMI
- Status last verified
- Feb 2026
- First submitted
- 13 Feb 2023
- Last updated
- 3 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 3 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Use of the Methoxyflurane as Pain-killer in the Prehospital Management of Acute Myocardial Infarction
- ClinicalTrials.gov ID
- NCT07445737
- Acronym / sponsor ID
- MAMI / APHP180610
- Keywords
- chest pain, morphine, methoxyflurane
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 700 participants (estimated)
- Lead sponsor
- Assistance Publique - Hôpitaux de ParisUniversity, hospital or other
- Collaborators
- Medical Developments International Limited
- Study start
- Jun 2026 (estimated)
- Primary completion
- Jun 2029 (estimated)
- Study completion
- Jun 2029 (estimated)
- First posted
- 3 Mar 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
- 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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Morphine | Active comparator | Drug: MorphineMorphine intra-venous infusion: 3 mg bolus repeated every 5 minutes until obtaining VAS ≤ 3 |
| Methoxyflurane | Experimental | Drug: MethoxyfluranePatient's self-administration of methoxyflurane (Penthrox®) with dedicated inhaler Initial dose: 3 mL (1 vial). A second 3 mL dose can be used. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- 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
Key exclusion criteria (21 listed)
- 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,
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| MethoxyfluraneAlso: Penthrox®Patient's self-administration of methoxyflurane (Penthrox®) with dedicated inhaler Initial dose: 3 mL (1 vial). A second 3 mL dose can be used. Treatment: from inclusion to hospital arrival. | Drug | Methoxyflurane |
| MorphineMorphine intra-venous infusion: 3 mg bolus repeated every 5 minutes until obtaining VAS ≤ 3. Treatment: from inclusion to hospital arrival | Drug | Morphine |
Primary outcome
Demonstrate that methoxyflurane self-administered by the patient is at least as efficient in achieving pain relief that morphine
Time frame: at 30 minutes
To demonstrate that methoxyflurane self-administered by the patient suffering chest pain related to an acute myocardial infarction is at least as efficient in achieving pain relief that morphine with better tolerance (achieving pain relief, i.e. pain intensity score on visual analogic scale (VAS) ≤ 3 at 30 minutes)
9 secondary outcomes
Compare the impact of the treatments on heart rate
Time frame: at 30 minutes
Compare the impact of the treatments on arterial blood pressure
Time frame: at 30 minutes
Compare the impact of the treatments on pulse oximetry
Time frame: at 30 minutes
Compare the impact of the treatments on ECG
Time frame: at 30 minutes
Compare tolerance of the treatments on respiratory depression
Time frame: at 30 minutes
Compare tolerance of the treatments on sedation
Time frame: at 30 minutes
Compare tolerance of the treatments on dizziness, pruritus, nausea, vomiting, headache
Time frame: at 30 minutes
Compare the impact of the treatments on pain relief
Time frame: From randomization until the first documented pain divided by two, assessed up to 30 minutes
Compare the impact of the treatments on pain relief
Time frame: From randomization until the first documented pain relief, assessed up to 30 minutes
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Mar 2026.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing Methoxyflurane and Morphine in people with STEMI - ST Elevation Myocardial Infarction, run by Assistance Publique - Hôpitaux de Paris at 1 site in France.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 21 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 3 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in France. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Frederic LAPOSTOLLE, MD,PHD (01 48 96 44 54 ext. +33, frederic.lapostolle@aphp.fr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Demonstrate that methoxyflurane self-administered by the patient is at least as efficient in achieving pain relief that morphine (time frame: at 30 minutes). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Mar 2026.