Methoxyflurane for Pain During IUD Insertion

Age: 18+

Sex: Female

Trial Phase: Academic

Sponsor: Mount Sinai Hospital, Canada

Must not be taking: Opioids, Benzodiazepines, Misoprostol

Disqualifiers: Chronic pain, Renal disease, others

Compensation: Varies

Number of Visits: 2

Duration: Single session

174 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to determine if inhaling 3ml of Methoxyflurane, a pain relief medication, can reduce pain during IUD insertion or an endometrial biopsy. Participants will receive either Methoxyflurane or a placebo (a substance with no therapeutic effect) through a Penthrox inhaler. The trial is double-blind, so neither participants nor researchers will know who receives which treatment, ensuring unbiased results. Individuals who have never had children, are undergoing an IUD insertion or biopsy, speak English, and have a ride home may be suitable for this trial. As an unphased trial, this study provides a unique opportunity to contribute to medical research and potentially benefit from innovative pain relief methods.

Will I have to stop taking my current medications?

You may need to stop taking certain medications, like opioids or benzodiazepines, 24 hours before the trial. The protocol does not specify other medications, so check with the trial team for more details.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research has shown that methoxyflurane is generally safe as an inhaled pain reliever. In past studies, it did not cause kidney or liver problems, making it a good choice for pain relief during minor procedures. Methoxyflurane is also considered safe and easy to use for outpatient procedures like hysteroscopies, which are similar to getting an IUD. Participants in these studies found it effective and acceptable, with fewer side effects than other pain medications. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Methoxyflurane is unique because it offers a different approach to managing pain during IUD insertion. Unlike traditional methods like NSAIDs or local anesthetics, which can take time to work and may not fully alleviate discomfort, Methoxyflurane is administered via a Penthrox inhaler, allowing for rapid pain relief. Researchers are excited about its potential to provide fast-acting, effective pain management with minimal invasiveness, enhancing the overall experience for those undergoing this procedure.

What evidence suggests that Methoxyflurane might be an effective treatment for pain during IUD insertion?

This trial will compare methoxyflurane with a placebo for pain reduction during IUD insertion. Research has shown that methoxyflurane, used with a Penthrox inhaler, effectively reduces pain during certain medical procedures. Studies have found it to be a safe and acceptable option for pain relief in outpatient settings, such as hysteroscopy or other intrauterine procedures. Patients using methoxyflurane reported less pain, making it a promising choice for managing discomfort during procedures like IUD insertion or endometrial biopsy. This suggests methoxyflurane may help reduce pain for individuals undergoing these specific procedures. ^{3 4 5 6 7}

Are You a Good Fit for This Trial?

This trial is for individuals undergoing IUD insertion or endometrial biopsy. Participants must meet certain criteria to join, but specific inclusion and exclusion details are not provided here.

Inclusion Criteria

I speak English.

I am between 18 and 65 years old and need an IUD insertion or endometrial biopsy.

For IUD insertion, only nulliparous patients

Exclusion Criteria

Baseline vital signs of systolic blood pressure less than 100, diastolic blood pressure less than 60, and/or pulse less than 60

I or my family have a history of severe reactions to anesthesia.

I have taken Misoprostol within the last 24 hours.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive either 3ml of Methoxyflurane or placebo via a Penthrox inhaler during IUD insertion or endometrial biopsy

Single session

1 visit (in-person)

Follow-up

Participants are monitored for immediate pain and satisfaction following the procedure

Immediate post-procedure

1 visit (in-person)

What Are the Treatments Tested in This Trial?

Interventions

• Methoxyflurane

Trial Overview The study tests if inhaling Methoxyflurane (Penthrox) reduces pain during the procedures compared to a placebo. It's a double-blind, randomized controlled trial where patients won't know if they're getting the real drug or saline solution.

How Is the Trial Designed?

Group I: 3ml of Methoxyflurane Experimental Treatment 1 Intervention

3ml of Methoxyflurane via a Penthrox inhaler

Group II: 3ml of normal saline Placebo Group 1 Intervention

3ml of normal saline via an identical placebo Penthrox inhaler

Who Is Running the Clinical Trial?

Mount Sinai Hospital, Canada

Lead Sponsor

Trials

210

Recruited

70,700+

Matthew Morton Research Award

Collaborator

Citations

1. pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov/39303369/

Inhaled methoxyflurane (Penthrox®) as a novel pain relief ... Conclusion: Penthrox® appears safe, feasible and acceptable as a pain relief option during outpatient hysteroscopy and other intrauterine procedures. The ...

2. anzctr.org.au anzctr.org.au/Trial/Registration/TrialReview.aspx?id=380045

Methoxyflurane analgesia for outpatient intrauterine device ... Phase 4, open, single centre, single arm pilot study of methoxyflurane inhalation during outpatient intrauterine device insertion.

3. ejog.org ejog.org/article/S0301-2115(24)00487-1/abstract

Inhaled methoxyflurane (Penthrox®) as a novel pain relief ... Penthrox® appears safe, feasible and acceptable as a pain relief option during outpatient hysteroscopy and other intrauterine procedures. The ...

4. clinicaltrials.gov clinicaltrials.gov/study/NCT07046572

Methoxyflurane for IUD Insertion and Endometrial Biopsy 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 ( ...

5. sciencedirect.com sciencedirect.com/science/article/abs/pii/S0301211524004871

Inhaled methoxyflurane (Penthrox®) as a novel pain relief ... Penthrox® appears safe, feasible and acceptable as a pain relief option during outpatient hysteroscopy and other intrauterine procedures.

6. sogc.org sogc.org/common/Uploaded%20files/ACSC/ACSC2025/DAY3_1220_NONACCREDITED_Inhaled%20methoxyflurane.pdf

Inhaled Analgesia in Gynaecologic Procedures Compared to other analgesics, the positive safety profile and the possibly lower potential for abuse makes methoxyflurane an attractive treatment option for ...

7. cda-amc.ca cda-amc.ca/methoxyflurane-inhalation-analgesic-minor-gynecological-ambulatory-or-emergency-procedures

Methoxyflurane Inhalation as an Analgesic for Minor ... Methoxyflurane at the analgesic dose appears to be safe — that is, not associated with kidney or liver toxicity and resulting in fewer ...