Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12619000804189
Ethics application status
Approved
Date submitted
24/04/2019
Date registered
3/06/2019
Date last updated
17/11/2022
Date data sharing statement initially provided
3/06/2019
Date results information initially provided
17/11/2022
Type of registration
Prospectively registered

Titles & IDs
Public title
Potential numbing affects of Urtica ferox
Scientific title
A prospective non-inferiority study comparing Urtica ferox exposure and 4% lidocaine in increasing thermal sensation and pain thresholds in healthy volunteers
Secondary ID [1] 298046 0
None
Universal Trial Number (UTN)
U1111-1232-2428
Trial acronym
UFEL
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Pain 312521 0
Condition category
Condition code
Neurological 311059 311059 0 0
Other neurological disorders

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Exposure to Urtica ferox will be topically administered once in a single exposure on the volar forearm in an area identified with a 15mm diameter circle denoted with indelible ink at time=0.

100 ug of standardised extract (equivelent to 5-10 trichromes by weight) will be placed on the skin and a skin scratched performed.

Immediately prior to administration the sensory testing will be performed in triplicate at the three test sites. Subsequent to administration of the intervention testing will be performed at 1, 3, 24, 48 and 72 hours.
Intervention code [1] 314277 0
Treatment: Other
Comparator / control treatment
There are three treatment groups in total: 4% lidocaine, placebo and Urtica ferox administration. Each area of exposure on the volar forearm in an area will be identified with a 15mm diameter circle created with indelible ink. Details for the two comparators follows:

1. 300 ul of 4% lidocaine is topically applied for 1 hour and covered with an occlusive dressing.
2. 300 ul of hand lotion (Nivea Rich Nourishing Lotion) is topically applied as placebo for 1 hour and covered with an occlusive dressing.
Control group
Placebo

Outcomes
Primary outcome [1] 319842 0
Using an established thermal probe testing paradigm a thermode to placed in contact with the treatment areas. The temperature of the probe increases at about 1C per second and when the participant feels warmth they report "warm" and when the sensation changes to pain they report "pain."

The primary outcome variable is where the patients first feels warmth from the thermal probe for at least 2 seconds.
Timepoint [1] 319842 0
The value of the sensory test for "warm" between the 3 groups is compared at 3 hours post-intervention.
Secondary outcome [1] 369655 0
Using an established thermal probe testing paradigm a thermode to placed in contact with the treatment areas. The temperature of the probe increases at about 1C per second and when the participant feels warmth they report "warm" and when the sensation changes to pain they report "pain."

This secondary outcome is the duration in hours from exposure where the "warm" thresholds are statistically differenet (95% CI) from the control.
Timepoint [1] 369655 0
The measure of "warm" at 0, 1, 3, 24, 48 and 72 hours.
Secondary outcome [2] 369656 0
Using an established thermal probe testing paradigm a thermode to placed in contact with the treatment areas. The temperature of the probe increases at about 1C per second and when the participant feels warmth they report "warm" and when the sensation changes to pain they report "pain."

This secondary outcome is the duration in hours from exposure where the "pain" thresholds are statistically differenet (95% CI) from the control.
Timepoint [2] 369656 0
The measure of warmth is assessed at 0, 1, 3, 24, 48 and 72 hours.
Secondary outcome [3] 369657 0
Positive sensory symptoms as defined as the presence or absence of allodynia, paresthesia, or hyperalgesia in the three groups.

The presence of these symptoms are determined by asking the participant if they have experienced:
1. For allodynia--Does light touch, such as probe placement, on the skin cause pain in any of the three areas?
2. For paresthesia--Is there any tingling, pricking, chilling, burning or numb sensation in any of the three groups
3. For hyperalgesia--Does the sensation of pain from the temperature probe feel more intense in any of the three groups?
Timepoint [3] 369657 0
The presence or absence of measure of allodynia, paresthesia, or hyperalgesia at 0, 1, 3, 24, 48, and 72 hours.
Secondary outcome [4] 369658 0
Difference in touch perception threshold as measured by grams of force with Semmes-Weinstein Monofilaments
Timepoint [4] 369658 0
The sensory measure is assessed at 0, 1, 3, 24, 48, and 72 hours.
Secondary outcome [5] 369659 0
Compliance with study protocol as measured by participants attending sensory testing.
Timepoint [5] 369659 0
Participants attending testing at 0, 1, 3, 24, 48, and 72 hours.
Secondary outcome [6] 369760 0
Using an established thermal probe testing paradigm a thermode to placed in contact with the treatment areas. The temperature of the probe increases at about 1C per second and when the participant feels warmth they report "warm" and when the sensation changes to pain they report "pain."

The primary outcome variable is where the patients first feels pain from the thermal probe for at least 2 seconds.
Timepoint [6] 369760 0
The value of the sensory test for "pain" between the 3 groups is compated at 3 hours post-intervention.

Eligibility
Key inclusion criteria
Age over 18
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Smoker
Known condition that causes neuropathy, particularly diabetes and excess alcohol intake.
Loss of hand
Loss of feeling in hand
Allergy to lidocaine or Urtica ferox

Study design
Purpose of the study
Treatment
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?


The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Other
Other design features
Phase
Not Applicable
Type of endpoint/s
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
10/09/2019
Actual
10/09/2019
Date of last participant enrolment
Anticipated
11/01/2022
Actual
4/04/2022
Date of last data collection
Anticipated
12/04/2022
Actual
4/04/2022
Sample size
Target
12
Accrual to date
Final
9
Recruitment outside Australia
Country [1] 21428 0
New Zealand
State/province [1] 21428 0
Tasman

Funding & Sponsors
Funding source category [1] 302576 0
University
Name [1] 302576 0
Nelson Marlborough Institute of Technology
Country [1] 302576 0
New Zealand
Primary sponsor type
University
Name
Nelson Marlborough Institute of Technology
Address
322 Hardy Street
Nelson 7010
Country
New Zealand
Secondary sponsor category [1] 302484 0
None
Name [1] 302484 0
Address [1] 302484 0
Country [1] 302484 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 303218 0
Health and Disability Ethics Committees
Ethics committee address [1] 303218 0
Ministry of Health
Health and Disability Ethics Committees
PO Box 5013
Wellington 6140
Ethics committee country [1] 303218 0
New Zealand
Date submitted for ethics approval [1] 303218 0
05/06/2019
Approval date [1] 303218 0
03/09/2019
Ethics approval number [1] 303218 0
19/NTA/107

Summary
Brief summary
The trichomes of the New Zealand endemic nettle ongaonga, Urtica ferox, may contain a novel compound with therapeutic potential. When skin is exposed to the liquid in the Urtica ferox trichomes, a suite of chemicals including acetylcholine, histamine and serotonin cause an immediate painful response. However, there is also potentially a yet-to-be identified compound that affects the peripheral nervous system causing anaesthesia, spontaneous and cold-induced paraethesias and allodynia and which appears to be exclusive to the New Zealand Urtica species. This compound may provide insight into the fundamental scientific neurobiology of the mechanisms whereby chemicals interact with dermal pain receptors and could potentially lead to a new therapeutic for treatment of neuropathic pain from disorders such as diabetic neuropathy, leprosy, or excessive alcohol consumption.

Despite the reports that there is an unidentified compound that affects the peripheral nervous system functioning as an analgesic these assumptions have never been clinically tested. Through controlled exposure to Urtica ferox and comparision to 4% lidocaine, this study aims to assess if exposure to Urtica ferox results in increased thermal sensation and thermal pain thresholds.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 92890 0
Prof Eric Buenz
Address 92890 0
Nelson Marlborough Institute of Technology
322 Hardy Street
Nelson 7010
Country 92890 0
New Zealand
Phone 92890 0
+64 (0) 3 546 9175
Fax 92890 0
Email 92890 0
Eric.Buenz@nmit.ac.nz
Contact person for public queries
Name 92891 0
Eric Buenz
Address 92891 0
Nelson Marlborough Institute of Technology
322 Hardy Street
Nelson 7010
Country 92891 0
New Zealand
Phone 92891 0
+64 (0) 3 546 9175
Fax 92891 0
Email 92891 0
Eric.Buenz@nmit.ac.nz
Contact person for scientific queries
Name 92892 0
Eric Buenz
Address 92892 0
Nelson Marlborough Institute of Technology
322 Hardy Street
Nelson 7010
Country 92892 0
New Zealand
Phone 92892 0
+64 (0) 3 546 9175
Fax 92892 0
Email 92892 0
Eric.Buenz@nmit.ac.nz

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
SourceTitleYear of PublicationDOI
EmbaseAnalgesia following controlled Urtica ferox extract exposure.2022https://dx.doi.org/10.1111/imj.15968
N.B. These documents automatically identified may not have been verified by the study sponsor.