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Efficacy and Safety of Methoxyflurane (Penthrox) for the Treatment of Acute Pain in Minor Trauma (STOP!)

This study has been completed.
ORION Clinical Services
Information provided by (Responsible Party):
Medical Developments International Limited Identifier:
First received: August 11, 2011
Last updated: October 30, 2012
Last verified: October 2012
This study investigates the treatment of acute pain, an unpleasant feeling caused by an injury. The overall purpose of the study is to gain more information that the pain relief medicine Penthrox(Methoxyflurane) administered using the Penthrox Inhaler(a distinctive green, whistle like object that you breathe through) is safe and works at relieving pain in patients aged 12 years and older who are admitted to a hospital Emergency Department with a minor injury (known as trauma).

Condition Intervention Phase
Acute Pain Due to Trauma
Drug: Methoxyflurane
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Participant, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: A Randomised, Double Blind, Multi-centre, Placebo Controlled Study to Evaluate the Efficacy and Safety of Methoxyflurane (Penthrox) for the Treatment of Acute Pain in Patients Presenting to an Emergency Department With Minor Trauma

Resource links provided by NLM:

Further study details as provided by Medical Developments International Limited:

Primary Outcome Measures:
  • VAS Score [ Time Frame: Twenty Minutes ]
    The difference between treatment and placebo on the VAS pain score

Secondary Outcome Measures:
  • Rescue Medication [ Time Frame: Up to a maximum of 6 hours ]
    A request for rescue medication, time of request for rescue medication and the quantity of opioid equivalent rescue medication administered will be measured

  • Time to pain relief [ Time Frame: Up to a maximum of 6 hours ]
    The number of inhalations of study treatment until pain relief is achieved and the time until pain relief is achieved.

  • Responder analysis [ Time Frame: Up to a maximum of 6 hours ]
    The number of responders will be defined

  • Safety Analysis [ Time Frame: Up to 16 days ]
    Evaluation of Adverse Events experienced during treatment. Evaluation of Adverse Events, including safety laboratory samples, up to 14 +/- 2 days following Emergency Department discharge

Enrollment: 300
Study Start Date: August 2011
Study Completion Date: July 2012
Primary Completion Date: July 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Methoxyflurane Drug: Methoxyflurane
Patients will have access to two 3 mL methoxyflurane (Penthrox) Inhalers or two 5mL placebo Inhalers to be self-administered.
Other Name: Penthrox
Placebo Comparator: Normal Saline Drug: Methoxyflurane
Patients will have access to two 3 mL methoxyflurane (Penthrox) Inhalers or two 5mL placebo Inhalers to be self-administered.
Other Name: Penthrox


Ages Eligible for Study:   12 Years and older   (Child, Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Patients 12 years of age or older who are able to give written informed consent or who are accompanied by a parent(s)/legal guardian able to provide written informed consent on their behalf.
  • Evidence of signed and dated informed consent document(s) indicating that the patient (and/or a parent/legal guardian) has been informed of all pertinent aspects of the study.
  • Pain Score ≥ 4 to ≤ 7 as measured using Numerical Rating Scale (NRS) at the time of admission, due to minor trauma.

Exclusion Criteria:

  • Life-threatening condition requiring immediate admission in the Operating Room or Intensive Care Unit.
  • Presence of any other clinical condition(s) that may, in the opinion of the investigator, impact on the patient's ability to participate in the study, or on the study results, including history of head injury and/or altered consciousness.
  • Unable to provide written informed consent.
  • Known pregnancy or lactation
  • Acute intoxication with drugs or alcohol, based on the judgement of the attending physician.
  • Treatment with any analgesic agent within 5 hours prior to presentation to ED (except diclofenac sodium which is prohibited within 8 hours prior to presentation to ED).
  • Current ongoing use of analgesics for chronic pain.
  • Use of an investigational product within one month prior to presentation to ED.
  • Known personal or familial hypersensitivity to fluorinated anaesthetics.
  • Known personal or familial history of malignant hyperthermia.
  • Clinically significant respiratory depression.
  • Use of methoxyflurane in the previous 4 weeks.
  • Known pre-existing clinically significant renal or hepatic impairment according to the judgement of the clinician.
  • Clinically significant cardiovascular instability.
  Contacts and Locations
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Please refer to this study by its identifier: NCT01420159

United Kingdom
Barnsley District General Hospital
Barnsley, United Kingdom, S75 2EP
Birmingham Children's Hospital NHS Foundation Trust
Birmingham, United Kingdom, B4 6NH
Colchester General Hospital
Colchester, United Kingdom, CO4 5JL
James Cook University Hospital
Middlesbrough, United Kingdom, TS4 3BW
Royal Victoria Infirmary
Newcastle-upon-Tyne, United Kingdom, NE1 4LP
Nottingham University Hospitals NHS Trust, Queen's Medical Centre Campus
Nottingham, United Kingdom, NG7 2UH
Sponsors and Collaborators
Medical Developments International Limited
ORION Clinical Services
Principal Investigator: Frank M Coffey Nottingham University Hospitals, Queen's Medical Centre Campus
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Medical Developments International Limited Identifier: NCT01420159     History of Changes
Other Study ID Numbers: MEOF-001
Study First Received: August 11, 2011
Last Updated: October 30, 2012

Keywords provided by Medical Developments International Limited:

Additional relevant MeSH terms:
Wounds and Injuries
Acute Pain
Neurologic Manifestations
Nervous System Diseases
Signs and Symptoms
Anesthetics, Inhalation
Anesthetics, General
Central Nervous System Depressants
Physiological Effects of Drugs processed this record on May 25, 2017