Testing Methoxyflurane against a placebo for endometrial biopsy
Official title: Methoxyflurane for IUD Insertion and Endometrial Biopsy
A Double-blind Placebo-controlled Randomized Controlled Trial (RCT) of 3ml Methoxyflurane for Intrauterine Device (IUD) Insertion and Endometrial Biopsy
- 2 groups
- One site, in Toronto
- Recruiting
Interventions
- Medication
Methoxyflurane - Penthrox
3ml of Methoxyflurane via a Penthrox inhaler
- Other intervention
Placebo Penthrox inhaler
3ml of normal saline via an identical placebo Penthrox inhaler
Canadian Sites (1)
1 of 1 recruiting
- Recruiting
OPG
Toronto, Ontario
Eligibility Criteria
See who this study is looking for25 criteria
The trial’s own eligibility text, word for word from the registry. Only the trial site can say who takes part.
Inclusion
- +Allergy to methoxyflurane
- +Any participant ≥18 years and ≤ 65 years presenting for an IUD insertion or endometrial biopsy
- +For IUD insertion, only nulliparous patients
- +English speaking participants only
- +Availability of a ride home from the appointment
- +Exclusion CriteriaExclusion criteriaThe things that would prevent someone from taking part.Read more →
- +Use of pain medication that is not an NSAID or acetaminophen (e.g. opioids, benzodiazepines) within past 24 hours
- +Misoprostol administration within 24 hours
- +Any diagnosed chronic pain syndromes (e.g. fibromyalgia, vaginismus)
- +Renal or liver disease
- +Known or genetically susceptible to malignant hyperthermia or a history of severe adverse reactions in either patient or relatives
- +BaselineBaselineYour starting measurements, taken before treatment begins.Read more → vital signs of systolic blood pressure \<100, diastolic blood pressure \<60 and/or pulse \<60.
- +Previous unsuccessful office attempt of IUD insertion or endometrial biopsy by the same practitioner (note of clarification: previous unsuccessful IUD insertion or biopsy attempt by a different practitioner will still be eligible)
- +Clinically evident respiratory impairment
- +Breastfeeding
Exclusion
- −Allergy to methoxyflurane
- −Use of pain medication that is not an NSAID or acetaminophen (e.g. opioids, benzodiazepines) within past 24 hours
- −Misoprostol administration within 24 hours
- −Any diagnosed chronic pain syndromes (e.g. fibromyalgia, vaginismus)
- −Renal or liver disease
- −Known or genetically susceptible to malignant hyperthermia or a history of severe adverse reactions in either patient or relatives
- −BaselineBaselineYour starting measurements, taken before treatment begins.Read more → vital signs of systolic blood pressure \<100, diastolic blood pressure \<60 and/or pulse \<60.
- −Previous unsuccessful office attempt of IUD insertion or endometrial biopsy by the same practitioner (note of clarification: previous unsuccessful IUD insertion or biopsy attempt by a different practitioner will still be eligible)
- −Clinically evident respiratory impairment
- −Breastfeeding
In plain language
Assembled directly from this trial’s registry record. Every sentence traces to a field below — nothing here is generated or interpreted.
What this study is
This study does not fall into the standard research categories.
This study is not organised into the usual phase numbers — that is common for device, behavioural, and diagnostic research.
From the trial registry
Built from these fields:
- designModule.designInfo.primaryPurpose
- designModule.phases
Who receives what
There are 2 groups in this study.
Group A receives Methoxyflurane - Penthrox.
Registry label: A: 3ml of Methoxyflurane
Group B, the placeboPlaceboA dummy treatment with no active medicine, used for comparison.Read more → group, receives Placebo Penthrox inhaler.
Registry label: B: 3ml of normal saline
From the trial registry
Built from these fields:
- armsInterventionsModule.armGroups[].label
- armsInterventionsModule.armGroups[].type
- armsInterventionsModule.armGroups[].interventionNames
How the study is run
Which group you would be placed in is decided by chance, like a coin flip — not by you and not by your doctor.
You, the study team, and the people analysing the results would all be kept unaware of which group you are in until the study ends.
From the trial registry
Built from these fields:
- designModule.designInfo.allocation
- designModule.designInfo.maskingInfo.masking
Is there a placebo?
One group receives a placeboPlaceboA dummy treatment with no active medicine, used for comparison.Read more → — a dummy treatment with no active medicine in it.
From the trial registry
Built from these fields:
- armsInterventionsModule.armGroups[].type
- armsInterventionsModule.armGroups[].interventionNames
Who the study is looking for
The study lists an age range of 18 years to 65 years.
The study lists female participants only.
The study accepts healthy volunteersHealthy volunteerSomeone without the condition being studied who takes part anyway.Read more → as well as people with the condition.
These are the criteria the study lists. Only the trial siteTrial siteA hospital or clinic where a study is actually run.Read more → can decide whether someone can take part.
From the trial registry
Built from these fields:
- eligibilityModule.minimumAge
- eligibilityModule.maximumAge
- eligibilityModule.sex
- eligibilityModule.healthyVolunteers
How big and how long
The study aims to enrol about 174 people.
The study is currently expected to finish around March 2026.
The main measurement is taken over: 5-minutes following the completion of the procedure.
From the trial registry
Built from these fields:
- designModule.enrollmentInfo.count
- statusModule.completionDateStruct.date
- outcomesModule.primaryOutcomes[].timeFrame
What the study measures
Global pain score — measured over 5-minutes following the completion of the procedure.
From the trial registry
Built from these fields:
- outcomesModule.primaryOutcomes[].measure
- outcomesModule.primaryOutcomes[].timeFrame
Source: NCT07046572 on ClinicalTrials.gov. The full registry text is further down this page — this summary never replaces it.
Not medical advice. What do these terms mean?
What is being tested — in plain terms
About Methoxyflurane - PenthroxDrug
3ml of Methoxyflurane via a Penthrox inhaler
From the trial registry — its own words, unedited.
What a drug is here: A medicine — a chemical or small-molecule treatment — given as the thing being studied.
Read the full explanation → · in clinical review
About Placebo Penthrox inhalerOther
3ml of normal saline via an identical placebo Penthrox inhaler
From the trial registry — its own words, unedited.
What a other is here: An intervention the registry did not place in another category.
Read the full explanation → · in clinical review
Common questions
Answered from this trial’s registry record. Where the record doesn’t say, these answers say so rather than filling the gap.
Am I eligible for this trial?
Only the trial siteTrial siteA hospital or clinic where a study is actually run.Read more → can decide whether someone can take part. Concord cannot make that determination, and neither can any tool that has not examined you.
What the study lists: an age range of 18 years to 65 years.
The full inclusionInclusion criteriaThe things you must have or be for a study to consider you.Read more → and exclusion criteriaExclusion criteriaThe things that would prevent someone from taking part.Read more → are published on this page, exactly as the study team wrote them.
The useful next step is to bring this trial to your doctor. Answering a few questions first gives them something concrete to review.
From the trial registry
- eligibilityModule.minimumAge
- eligibilityModule.maximumAge
- eligibilityModule.eligibilityCriteria
Is there a placebo?
Yes. This study includes a placeboPlaceboA dummy treatment with no active medicine, used for comparison.Read more → group — a dummy treatment with no active medicine in it.
From the trial registry
- armsInterventionsModule.armGroups[].type
Would I know which treatment I am getting?
You, the study team, and the people analysing the results would all be kept unaware of which group you are in until the study ends.
Which group you would be placed in is decided by chance, like a coin flip — not by you and not by your doctor.
From the trial registry
- designModule.designInfo.maskingInfo.masking
- designModule.designInfo.allocation
Who can join?
The study lists an age range of 18 years to 65 years.
It lists female participants only.
It accepts healthy volunteersHealthy volunteerSomeone without the condition being studied who takes part anyway.Read more → as well as people with the condition.
Only the trial siteTrial siteA hospital or clinic where a study is actually run.Read more → can confirm whether a particular person can take part.
From the trial registry
- eligibilityModule.minimumAge
- eligibilityModule.maximumAge
- eligibilityModule.sex
- eligibilityModule.healthyVolunteers
How long would this take?
The study's main measurement is taken over: 5-minutes following the completion of the procedure.
The study as a whole is currently expected to finish around 2026-03-01.
How long any one person takes part can differ from the study length. The study team can tell you what the schedule looks like in practice.
From the trial registry
- outcomesModule.primaryOutcomes[].timeFrame
- statusModule.completionDateStruct.date
How many people are taking part?
The study aims to enrol about 174 people.
From the trial registry
- designModule.enrollmentInfo.count
Where is this happening?
This study lists one location: Toronto, Ontario, Canada.
Sites can open and close during a study, so confirm with the team before travelling.
From the trial registry
- trial_locations
About This Trial
The aim of this study is to determine if 3ml of inhaled Methoxyflurane, in the form of a Penthrox inhaler, reduces pain during IUD insertion and/or endometrial biopsy. The proposed study is a double-blind, placebo-controlled RCT. Each participant will be randomly assigned to one of two arms: 1. Intervention (3ml of Methoxyflurane via a Penthrox inhaler) 2. Placebo (3ml of normal saline via an identical placebo Penthrox inhaler) The primary outcome is global pain score, which will be patient-reported by the 100 mm Visual Analogue Scale (VAS) 5-minutes following the procedure (endometrial biopsy or IUD insertion).
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See if this trial could fit youThis page is for informational purposes only and does not constitute medical advice. Clinical trial eligibility can only be determined by the trial site after proper screening. Trial information is sourced from ClinicalTrials.gov and may not reflect the most current status. Always consult your healthcare provider before making decisions about clinical trial participation.