Effects of inhaled methoxyflurane (Penthrox) on psychomotor function in humans: a randomized placebo trial

For healthy volunteers and subjects who undergo colonoscopy, will using Penthrox as a modality of analgesia have little or no effect on psychomotor function because of its minimal sedative effect.

Status

Completed

Phases

Phase 4

Study type

Interventional

Source

ANZCTR

Registry ID

ACTRN12613000666729

Enrollment

Registered

2013-06-19

Start date

2014-05-28

Completion date

2015-05-20

Last updated

2020-01-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

None listed

Brief summary

An unanswered issue relates to the use of Penthrox in clinical setting is its impact on psychomotor function and the ability to driving or operating complex tasks, as the lack of adverse psychomotor effects from Penthrox may allow patients to drive, and even return to work on the same day of the colonoscopy. Given colonoscopy is increasingly performed for screening and surveillance purposes, the ability to return home or work place without carers would carry significant cost benefit and minimize work disruption. Currently, there are no data on the impact of inhaled Penthrox, or methoxyflurane in general, on the psychomotor function in humans. The aim of this study is, therefore, to evaluate the effects of inhaled Penthrox on psychomotor functions of healthy volunteers as well as subjects who undergo colonoscopy with Penthrox. Hypothesis: Inhaled methoxyflurane has minimal sedative effect and thus, has minimal or no effect of psychomotor function in humans.

Interventions

Name: Methoxyflurance Inhalation Analgesic Dose: 1 x 3mL bottle of Penthrox (methoxyflurane) , vaporised in and then inhaled through a Penthrox Inhaler. For colonoscopy patients, a nurse will teach and instruct patients to take several inhalations initially before the commencement of the procedure. Depending on the amount of pain experienced during the procedure, they are allowed to take further inhalations as required. Furthermore, if the colonoscopist is able to anticipate discomfort due to a difficult section of the bowel, they will ask the patient to take a few more inhalations to cover for potential discomfort or pain. All inhalations will be from one Penthrox bottle. For Healthy patients, methroxyflurane is inhaled continuously through one Penthrox Bottle for a duration of 20 min before psychomotor testing

Study design

Allocation

Randomised controlled trial

Intervention model

Other

Primary purpose

Treatment

Masking

Blinded (masking used) (Subject, Caregiver, Outcomes Assessor)

Eligibility

Sex/Gender

All

Age

18 Years to 79 Years

Healthy volunteers

Yes

Inclusion criteria

Able to give informed consent Adequate understanding of use of the Penthrox inhaler

Exclusion criteria

History of significant alcohol (>40gms/d for males, 20gms/d for females) or narcotic use. Previous history of significant cardiac or respiratory illnesses (ie. ischaemic heart disease, chronic obstructive pulmonary disease). Significantly underweight (<45kg) Significant smoking history of more than 20 packs / year. Previous history of gastrointestinal surgery (likely to increase difficulty of colonoscopy) Renal impairment Diabetes Mellitus Previous possible allergy to the medication by the patient or a relative Hypersensitivity to fluorinated agents Previous head injury Difficulty in following instructions (including language barrier) Patients taking any potential nephrotoxic drugs (e.g. aminoglycosides) Malignant hyperthermia

Outcome results