GABA-B Receptor Function in Healthy Volunteers

GABA-B Receptor Function in Healthy Volunteers: a Pilot, Double Blind Crossover Study of the Effects of 2 Doses of Baclofen and Placebo on Objective and Subjective Measurements of Brain Function

There are several developing lines of evidence suggesting that brain receptors called GABA-B receptors play a significant role in addiction and its treatment. The investigators wish to examine the sensitivity of brain GABA-B receptors in alcohol and opiate addicts as part of the investigators MRC programme of research in neurotransmitters in alcohol and opiate addiction (NOAA). In this present study the investigators will give 2 different single doses of a drug called baclofen, and a placebo, to 8 healthy male volunteers. This drug affects GABA-B receptors in the central nervous system and is licensed for the treatment of spasticity in people with eg spinal injuries; the investigators are interested in its effects on brain GABA-B receptors. The investigators will measure EEG (brainwaves), eye movements, blood pressure and heart rate, motor co-ordination and subjective effects and also blood levels of the drug in the investigators volunteers before and at intervals after dosing. The investigators will use a double-blind randomised design to minimise expectation effects. The study will provide information on timing and magnitude of effects of baclofen on brain function in healthy subjects so that the investigators can optimise selection and timing of functional measures in future studies of addicts.

Study Overview

• Status: Completed
• Conditions: No Condition; Brain GABA-B Function
• Intervention / Treatment: Drug: placebo; Drug: Baclofen 10mg; Drug: Baclofen 60mg

Detailed Description

After informed consent and screening participants will attend for 3 study days. On each of these there will be a set of baseline measurements including EEG, saccadic eye movements, vital signs, motor co-ordination task, subjective visual analogue ratings and questionnaires and blood sample. After dosing these measurements will be repeated at intervals during the day up to 6 hours after dosing. Participants will be allowed home after a health check.

• Study Type: Interventional
• Enrollment (Actual): 8
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • London, United Kingdom, W12 0NN
    • Neuropsychopharmacology, Imperial College

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years to 40 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

• Currently healthy
• Non-smoker
• Willing to comply with protocol
• Excellent understanding of English (for questionnaires)
• Alcohol consumption between 1 and 28 units/week

Exclusion Criteria:

• Current or past history of psychiatric or substance use disorder

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Interventional Model: Crossover Assignment
• Masking: Triple

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: single group, crossover, 3 interventions	Drug: placebo; placebo; Drug: Baclofen 10mg; Baclofen 10mg single dose po; Drug: Baclofen 60mg; Baclofen 60mg single dose po

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
EEG spectral power in theta band	Change from baseline to 4 hours after dosing

Collaborators and Investigators

• Sponsor: Imperial College London
• Collaborators: Medical Research Council
• Investigators: Principal Investigator: Anne Lingford-Hughes, MRCPsych PhD, Imperial College London

Study record dates

Study Major Dates

• Study Start: July 1, 2013
• Primary Completion (Actual): September 1, 2014
• Study Completion (Actual): September 1, 2014

Study Registration Dates

• First Submitted: February 13, 2012
• First Submitted That Met QC Criteria: March 22, 2012
• First Posted (Estimate): March 26, 2012

Study Record Updates

• Last Update Posted (Estimate): June 4, 2015
• Last Update Submitted That Met QC Criteria: June 3, 2015
• Last Verified: September 1, 2014

More Information

Terms related to this study

• Keywords: GABA-B
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Peripheral Nervous System Agents; GABA Agents; Neuromuscular Agents; Muscle Relaxants, Central; GABA Agonists; GABA-B Receptor Agonists; Baclofen
• Other Study ID Numbers: NOAA/001/2011