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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
The use of tiagabine and gabapentin in the treatment of social anxiety disorder in 8 patients
Scientific title
Gabapentin and tiagabine for treatment of social anxiety disorder in 8 patients in a random double blind crossover study with outcome measured as changes in the Leibowitz Social Anxiety Scale
Secondary ID [1] 771 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Subjects with social anxiety disorder 4141 0
Condition category
Condition code
Mental Health 4344 4344 0 0

Study type
Description of intervention(s) / exposure
Each subject was titrated to either 1800 mg gabapentin oral tablets daily or 2400 mg tiagabine oral tablets daily by mouth and stayed at that dosage for 4 weeks before being washed out for 2 weeks and receiving whichever medication they had not initially received.
Intervention code [1] 3855 0
Treatment: Drugs
Comparator / control treatment
This study was a randomized double blind crossover study so that each subject was its own control
Control group

Primary outcome [1] 5223 0
Liebowitz Social Anxiety Scale: social anxiety
Timepoint [1] 5223 0
Measured at 2 weeks, 4 weeks, 8 weeks, 10 weeks, 14 weeks, and 16 weeks after randomization
Secondary outcome [1] 8806 0
Clinical Global impression scale: severity of illness and global functioning
Timepoint [1] 8806 0
Measured at 2 weeks, 4 weeks, 8 weeks, 10 weeks, 14 weeks, and 16 weeks after randomization

Key inclusion criteria
diagnosis of social anxiety disorder by DSM-IV criterial and a Liebowitz Socail Anxiety Scale greater than 30.
Minimum age
18 Years
Maximum age
65 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Other Axis I psychiatric disorders, major medical illnesses, taking medications that interacted with the study drugs, actively using alcohol or illegal drugs, were pregnant, planning to become pregnant, or breastfeeding

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation concealment was done by a research coordinator who had no contact with subjects. The research coordinator put the study medication in a sealed opaque envelope for the investigator who did not know the contents of the envelope for distribution to the subject.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomization by using a randomization table from a statistics book
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Phase 2 / Phase 3
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 1478 0
United States of America
State/province [1] 1478 0

Funding & Sponsors
Funding source category [1] 4310 0
Name [1] 4310 0
Norfolk Foundation
Address [1] 4310 0
1 Commercial Place
Norfolk VA 23501
Country [1] 4310 0
United States of America
Primary sponsor type
Maria Urbano, M.D.
Dept. of Psychiatry
Eastern Virginia Medical School
825 Fairfax Ave.
Norfolk VA
United States 23507
United States of America
Secondary sponsor category [1] 3882 0
Name [1] 3882 0
David R. Spiegel, M.D.
Address [1] 3882 0
Dept. of Psychiatry
Eastern Virginia Medical School
825 Fairfax Ave.
Norfolk VA
United States 23507
Country [1] 3882 0
United States of America

Ethics approval
Ethics application status
Ethics committee name [1] 6357 0
Eastern Virginia Medical School Institutional Review Board
Ethics committee address [1] 6357 0
Eastern Virginia Medical School
P.O. Box 1980
Norfolk VA 23510
Ethics committee country [1] 6357 0
United States of America
Date submitted for ethics approval [1] 6357 0
Approval date [1] 6357 0
Ethics approval number [1] 6357 0

Brief summary
Social Anxiety Disorder creates stress and significant disability for patients. Common treatments like selective serotonin reuptake inhibitors and benzodiazepines have undesirable side effects like sexual dysfunction or the potential for drug abuse/ dependence. The objective of the study was to see if alternative medications - tiagabine and gabapentin - already shown to be effective in other anxiety disorders might be effective for social anxiety disorder too. Subjects were selected to have social anxiety disorder by meeting the DSM-IV criteria and having a high score on the Liebowitz Social Anxiety Scale. Subjects were chosen who were generally healthy and had no other psychiatric diagnoses. They received a physical exam and lab work before starting the study. Each individual received each medication at a steady dosage for 4 weeks after being slowly increased for two weeks. The subjects took a Liebowitz Social Anxiety Scale and Clinical Global Impression Scale on each visit as well as reported efficacy of the medication (unknown to the patient or the investigator) and any side effects. Eight patients completed the study. Both medications were well tolerated with sedation and mild dizziness being the most common. All subjects with severe social anxiety responded well to both medications with two subjects reaching remission of symptoms. Gabapentin and tiagabine should be considered as effective alternate treatments for social anxiety disorder.
Trial website
Trial related presentations / publications
Gabapentin and Tiagabine for Social Anxiety Disorder: A Randomized, Double Blind Crossover Study of 8 Adults
This paper has been submitted and accepted for publication in the Primary Care Companion of the Journal of Clinical Psychiatry. It has not been assigned a publication date.
Public notes

Principal investigator
Name 35047 0
Address 35047 0
Country 35047 0
Phone 35047 0
Fax 35047 0
Email 35047 0
Contact person for public queries
Name 12394 0
Maria R. Urbano, M.D.
Address 12394 0
Dept. of Psychiatry
Eastern Virginia Medical School
825 Fairfax Ave.
Norfolk VA United States of America
Country 12394 0
United States of America
Phone 12394 0
Fax 12394 0
Email 12394 0
Contact person for scientific queries
Name 3322 0
Maria R. Urbano, M.D.
Address 3322 0
Dept. of Psychiatry
EasternVirginia Medical School
825 Fairfax Ave.
Norfolk VA United States of America
Country 3322 0
United States of America
Phone 3322 0
Fax 3322 0
Email 3322 0

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary