Efficacy of Inhaled Methoxyflurane (Penthrox) as Adjunct for Urologic Procedures Under Local Anesthetic: A Pilot Study

NCT07192198 | Completed Phase 2 FDA Drug

• 1 other identifier: HS26348
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

Brief Summary

We wish to perform a prospective randomized controlled pilot study at the Men's Health Clinic and Health Science's Centre to assess whether or not the use of Penthrox as an adjunct to LA is associated with improved pain tolerance and anxiety levels than local anesthetic alone

Conditions

Scrotum Disease; Hydrocele Male; Spermatocele; Scrotal Hematocele; Anesthesia, Local

Outcome Measures

Primary Outcomes (2)

• Pain with local anesthetic infiltration

  Using a visual analogue pain scale \[range 0-10; 0 = no pain, 10 = maximal pain\], pain will be assessed as reported by the patient when the local anesthetic injection is administered

  Immediately post-infiltration, intraoperatively

• Procedural pain

  Using a visual analogue pain scale \[range 0-10; 0 = no pain, 10 = maximal pain\], pain will be assessed as reported by the patient post-operatively to determine their pain

  Immediately post-operation

Study Arms (2)

Intervention arm-Penthrox

EXPERIMENTAL

Participants can begin using penthrox 10 minutes prior to procedure start, given its median onset time of 5 minutes

Drug: Methoxyflurane

Control arm

PLACEBO COMPARATOR

Patients in the control arm will only receive local infiltration.

Other: Control

Interventions

Methoxyflurane DRUG

Penthrox is a brand name for a drug called methoxyflurane. It is an inhaled analgesic (pain-relieving) agent used primarily for the relief of moderate to severe pain, typically in emergency medical situations or during minor medical procedures. Penthrox is administered by inhaling the vapors through a hand-held inhaler device. It acts quickly to provide pain relief and has a relatively short duration of action.

Intervention arm-Penthrox

Control OTHER

This intervention will be the control group, only receiving local infiltration.

Control arm

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adult patients undergoing hydrocelectomy, spermatocelectomy, epididymectomy, testicular biopsy, scrotal lesion or cyst excision under local anesthesia alone will be included.

You may not qualify if:

• Patients will be excluded if their procedure was to be performed with sedatives (e.g., inhaled nitrous oxide gas, oral, or IV sedation) or did not provide consent to be randomized

Sponsors & Collaborators

• University of Manitoba: lead

Study Sites (1)

Men's Health Clinic

Winnipeg, Manitoba, R3K 1M3, Canada

Location

MeSH Terms

Conditions

Spermatocele; Hematocele

Interventions

Methoxyflurane

Condition Hierarchy (Ancestors)

Genital Diseases, Male; Genital Diseases; Urogenital Diseases; Male Urogenital Diseases; Cysts; Pathological Conditions, Anatomical; Pathological Conditions, Signs and Symptoms; Hemorrhage; Pathologic Processes

Intervention Hierarchy (Ancestors)

Ethyl Ethers; Ethers; Organic Chemicals; Methyl Ethers

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, CARE PROVIDER
• Masking Details: The surgeon and patient are both blinded to which cream is being utilized, whether it be Penthrox, or a control. Investigators and study personnel are not blinded to this.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor, Department of Surgery. Director, Undergraduate Urologic Medical Education

Model Details: Double blinded, placebo controlled, randomized trial. Two arms, one is the intervention arm which will receive Penthrox and local anesthesia infiltration while the control arm will receive local anesthesia infiltration.

Study Record Dates

• First Submitted: February 16, 2024
• First Posted: September 25, 2025
• Study Start: April 17, 2024
• Primary Completion: November 27, 2024
• Study Completion: December 19, 2024
• Last Updated: September 25, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)