Methoxyflurane for IUD Insertion and Endometrial Biopsy | NCT07046572

Studies
Methoxyflurane for IUD Insertion and Endometrial Biopsy

NCT07046572

Sponsor

Mount Sinai Hospital, Canada

Status

Recruiting

Last Update Posted

Jul 30, 2025Actual

Enrollment

174Estimated

Phase

Not Applicable

Conditions

Endometrial Biopsy
Intrauterine Devices

Interventions

Methoxyflurane - Penthrox
Placebo Penthrox inhaler

Countries

Canada

Protocol Section

Identification Module Status Module Sponsor/Collaborators Module Oversight Module Description Module Conditions Module Design Module Arms/Interventions Module Outcomes Module Eligibility Module Contacts/Locations Module References Module IPD Sharing Statement Module

Results Section

Participant Flow Module Baseline Characteristics Module Outcome Measures Module Adverse Events Module More Info Module

Annotation Section

Annotation Module

Document Section

Large Document Module

Derived Section

Miscellaneous Info Module Condition Browse Module Intervention Browse Module

Protocol Section

Identification Module

NCT ID

Results Section

No data available

No data is available for this block.

Annotation Section

No data available

No data is available for this block.

Document Section

No data available

No data is available for this block.

Derived Section

Miscellaneous Info Module

Version Holder

Status Module

Record Verification Date

Jul 2025

Overall Recruitment Status or Expanded Access Status

Recruiting

Last Known Status

Not provided

Delayed Posting

Not provided

Why Stopped

Not provided

Expanded Access Info

Start Date

Jul 24, 2025Actual

Primary Completion Date

Dec 1, 2025Estimated

Completion Date

Mar 1, 2026Estimated

First Submitted Date

Jun 20, 2025

First Submission Date that Met QC Criteria

Jun 27, 2025

First Posted Date

Jul 1, 2025Actual

Results Waived

Not provided

Results First Submitted Date

Not provided

Results First Submitted that Met QC Criteria

Not provided

Results First Posted Date

Not provided

Certification/Extension (aka Delayed Results) First Submitted Date

Not provided

Certification/Extension First Submitted that Passed QC Review

Not provided

Certification/Extension First Posted Date

Not provided

Last Update Submitted Date

Jul 28, 2025

Last Update Posted Date

Jul 30, 2025Actual

Name	Class
Matthew Morton Research Award	UNKNOWN

Oversight Module

Has Data Monitoring Committee (DMC)

Is FDA Regulated Drug

Is FDA Regulated Device

Is Unapproved Device

Not provided

Pediatric Postmarket Surveillance of a Device Product

Not provided

Product Exported from US

Not provided

FDAAA801 Violation

Not provided

Description Module

Brief Summary

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:

Intervention (3ml of Methoxyflurane via a Penthrox inhaler)
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).

Detailed Description

Not provided

Design Module

Study Type

Interventional

Number of References to an Expanded Access Study

Not provided

Expanded Access Types

Not provided

Patient Registry

Not provided

Target Follow-Up Duration

Not provided

Phases

Not Applicable

Interventional Study Design

Allocation

Biospecimen

No data available

No data is available for this block.

Enrollment

174Estimated

Arms/Interventions Module

Arm Groups

Label	Type	Description	Intervention Names
3ml of Methoxyflurane	Experimental	3ml of Methoxyflurane via a Penthrox inhaler	Drug: Methoxyflurane - Penthrox
3ml of normal saline	Placebo Comparator	3ml of normal saline via an identical placebo Penthrox inhaler	Other: Placebo Penthrox inhaler

Interventions

Name	Type	Description	Arm Group Labels	Other Names
Methoxyflurane - Penthrox	Drug	3ml of Methoxyflurane via a Penthrox inhaler	3ml of Methoxyflurane

Outcomes Module

Primary Outcomes

Measure	Description	Time Frame
Global pain score	Patient reported pain by the 100 mm Visual Analogue Scale (VAS), minimum value 0 (no pain at all) and maximum value 100 (worst pain imaginable), higher scores indicate greater pain intensity.	5-minutes following the completion of the procedure

Secondary Outcomes

Measure	Description	Time Frame
Pain scores during procedure	Patient-reported verbal pain scores on a scale from 0 (no pain) to 10 (worst pain imaginable) at the following timepoints: baseline before inhaler, baseline after inhaler, insertion of speculum, tap cervix with sound, placement of tenaculum, sounding (IUD only), IUD insertion/endometrial biopsy, and 1-minute post-procedure. Higher scores indicate greater pain intensity.

Other Outcomes

Not provided

Eligibility Module

Eligibility Criteria

Inclusion Criteria

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 Criteria

Use of pain medication that is not an NSAID or acetaminophen (e.g. opioids, benzodiazepines) within past 24 hours
Misoprostol administration within 24 hours
Breastfeeding
Any diagnosed chronic pain syndromes (e.g. fibromyalgia, vaginismus)
Allergy to methoxyflurane
Renal or liver disease
Known or genetically susceptible to malignant hyperthermia or a history of severe adverse reactions in either patient or relatives
Baseline 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

Accepts Healthy Volunteers

Yes

Sex

Female

Sex/Gender Based

Not provided

Sex/Gender Description

Not provided

Minimum Age

18 Years

Maximum Age

65 Years

Standard Ages

AdultOlder Adult

Study Population

Not provided

Sampling Method

Not provided

Facility	Status	City	State	ZIP	Country	Contacts
OPG	Recruiting	Toronto	Ontario	M5G 1Z5	Canada

IPD Sharing Statement Module

Plan to Share IPD

Description

Not provided

Types

Not provided

Time Frame

Not provided

Access Criteria

Not provided

URL

Not provided

Intervention Model Description

The proposed study is a double-blind randomized controlled trial. Participants will be recruited from Mount Sinai Hospital outpatient gynecology clinics. Recruitment, consent, randomization, procedure, and post-procedure survey will occur during the same visit. Each participant will be randomly assigned to one of two arms: 1) intervention (3ml of Methoxyflurane via a Penthrox inhaler) or 2) placebo (3ml of normal saline via an identical placebo Penthrox inhaler). The primary outcome will be a global pain score, which will be patient-reported by the 100 mm Visual Analogue Scale (VAS) following the procedure.

Masking Info

Masking

Triple

Masking Description

The research coordinator (who is not involved in direct patient care) will open the allocation envelopes without the presence of the participant or the provider. They will prepare the Penthrox inhalers with either 3 mL methoxyflurane or 3 mL normal saline with a few drops of methoxyflurane on the outside of the inhaler to maintain blinding (as methoxyflurane has a distinct smell). The research coordinator will label each Penthrox inhaler with the study ID number.

The provider (who is blinded to the study) will enter the patient room with the procedure tray and the Penthrox inhaler. They will instruct the patient to inhale for 10 breaths with their finger covering the dilutor hole of the Penthrox inhaler. Once the patient has taken 10 breaths, the research assistant will start a timer for 5 minutes. The research assistant will inform the OB-GYN once the 5 minutes have passed and at that point the OB-GYN will start the procedure. All data will remain blinded until data analysis.

Who Masked

ParticipantCare ProviderInvestigator