Assessment of Peripheral GABA Receptors for Local Pain Relief

Not Applicable

• Conditions: Pain
• Interventions: Drug: Pain modulation; Drug: Intramuscular GABA; Drug: GABA oral solution

• Registration Number: NCT02928328
• Lead Sponsor: Aalborg University

Brief Summary

The effect of peripheral GABAA receptor activation on pain and sensitivity in healthy human subjects has never been investigated. However, as earlier studies suggest that activation of peripheral GABAA receptors is anti-nociceptive in rats, it is important to determine if these findings can be translated into human subjects to determine if peripheral GABAA receptors are a viable target for future analgesic drug development.

Detailed Description

Subproject I This study will test if oral administration of GABA containing solutions will reduce the pain and sensitivity induced by application of capsaicin to the tongue of healthy human subjects. Thirty, pain-free men (n=15) and women (n=15) for the oral cavity study.

Subproject II This study will test the hypothesis that intramuscular injection of GABA alone will not be painful, but will reduce muscle pain sensitivity in healthy human subjects. Thirty, pain-free men (n=15) and women (n=15) will be recruited for the intramuscular GABA injection studies

Subproject III This study will test the hypothesis that intramuscular injection of GABA with glutamate will decrease the intensity of glutamate-evoked muscle pain in healthy human subjects. Thirty, pain-free men (n=15) and women (n=15) will be recruited for the intramuscular glutamate and GABA injection studies.

Study Timeline

• Study Start: 2016-10
• Study First Submitted: 2016-10-06
• Study First Submitted QC: 2016-10-07
• Study First Posted: 2016-10-10
• Status Verified: 2018-01
• Last Update Submitted: 2018-01-08
• Last Update Posted: 2018-01-10
• Primary Completion: 2018-12
• Study Completion: 2019-12

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 90

Inclusion Criteria

• Aged 20-40 years
• Free from ongoing or chronic pain
• Adequate conversational English

Exclusion Criteria

• Pregnancy or intent to become pregnant, breast feeding
• Signs or symptoms of any serious systemic diseases
• Current malignancies
• High blood pressure
• Requirement for chronic administration of psychiatric, analgesic or other medications that might influence their response to pain
• Frequent recreational drug or alcohol use
• Previous neurologic, musculoskeletal or mental illnesses
• Lack of ability to cooperate

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Pain modulation	Pain modulation	This study will test the hypothesis that intramuscular injection of GABA with glutamate will decrease the intensity of glutamate-evoked muscle pain in healthy human subjects.
Intramuscular GABA	Intramuscular GABA	This study will test the hypothesis that intramuscular injection of GABA alone will not be painful, but will reduce muscle pain sensitivity in healthy human subjects.
GABA oral solution	GABA oral solution	This study will test if oral administration of GABA containing solutions will reduce the pain and sensitivity induced by application of capsaicin to the tongue of healthy human subjects.

Primary Outcome Measures

Name	Time	Method
Pain Intensity Rating	continuously for 95 minutes	visual analogue scale

Secondary Outcome Measures

Name	Time	Method
Jaw Function Tests	every 5 min for 50 minutes	maximal jaw opening, maximal bite force
Quantitative Sensory testing	every 10 min for 90 min	Pressure detection and pain threshold, thermal detection and pain threshold

Trial Locations

Locations (1)

Aalborg University; 🇩🇰 Aalborg, Denmark