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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Date results information initially provided
Type of registration
Prospectively registered

Titles & IDs
Public title
Effects of glutamate modulation on anxiety symptoms
Scientific title
Effect of ketamine on anxiety ratings in patients with anxiety disorders
Secondary ID [1] 286794 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Anxiety Disorders 295168 0
Condition category
Condition code
Mental Health 295413 295413 0 0

Study type
Description of intervention(s) / exposure
This study has three Phases
1. Open label within-subject ascending single dosing of ketamine (dose range 0.25, 0.5, 1 mg/kg subcutaneously (SC)) in patients with Generalized Anxiety Disorder (GAD) or Social Phobia (SP) (n=6/diagnosis). Unless there are individual toleration problems, it is anticipated all patients will receive all doses. There will be approximately 1 week between doses.
2. Double-blind within-subject ascending single dosing of ketamine (dose range 0.25, 0.5, 1 mg/kg subcutaneously) plus double blind active control (midazolam 0.01mg/kg SC) in a separate group of patients with GAD or SP (n=6/diagnosis). The timing of the midazolam dose will be randomized within the ascending ketamine doses. There will be approximately 1 week between doses.
3. Patients will be eligible to enter Phase 3 once they have completed either Phase 1 or Phase 2; entry to Phase 3 will be immediately after completing Phase 1 or Phase 2. They must also have had at least 50% reduction in anxiety ratings in response to any dose of ketamine are eligible to receive 1-2x weekly ketamine dosing for up to 3 months to help maintain improvement in anxiety symptoms. The Phase 3 dose will be individualized based on the balance between optimal tolerability and efficacy.
Intervention code [1] 291952 0
Treatment: Drugs
Comparator / control treatment
Single dose of midazolam 0.01mg/kg sc in Phase 2.
Control group

Primary outcome [1] 295150 0
Change in anxiety rating scales (GAD: Hamilton Anxiety Scale (HAM-A); SP: Spielberger State Anxiety Inventory (SSAI) plus Fear Questionnaire (FQ) items 3, 7, 9, 11, & 14h)– predose, 1h, 2h, 24h, 72h, 168h. Primary endpoint is change at 24h.
Timepoint [1] 295150 0
Primary endpoint is change at 24h.
Secondary outcome [1] 314877 0
Safety: vital signs (blood pressure, heart rate, O2 sats)
Timepoint [1] 314877 0
Screening and predose, 0:15, 0:30, 0:45, 1:00, 1:30, 2:00h and 24h post-dosing at each dose.
Secondary outcome [2] 314878 0
Tolerability: reported adverse events. Most commonly patients report feeling woozy or dissociated 10-20mins post dosing. These can be assessed by self-report, or via use of the CADSS scale.
Timepoint [2] 314878 0
Wooziness and dissociation will be assessed predose until 1h post dose. Adverse events will be recorded throughout the study.
Secondary outcome [3] 314879 0
Blood samples for plasma ketamine and metabolite concentrations, after each dose
Timepoint [3] 314879 0
predose, 15, 30, 60 and 120mins, and at 24h post each dose
Secondary outcome [4] 314880 0
Clinician Administered Dissociative Symptoms Scale (CADSS)
Timepoint [4] 314880 0
predose, 30 and 60mins post- each dose
Secondary outcome [5] 314881 0
Montgomery Asberg Depression rating Scale (MADRS)
Timepoint [5] 314881 0
at screening, predose and 24h post- each dose
Secondary outcome [6] 314988 0
Blood samples for plasma BDNF concentrations
Timepoint [6] 314988 0
Predose, 15, 30, 60 and 120mins, and at 24h post each dose

Key inclusion criteria
GAD patients must have a Hamilton Anxiety Scale (HAM-A) score >20
SP patients must have a Liebowitz Social Anxiety Scale (LSAS) self-report score >50.
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
1.Female patients who are or intend to become pregnant, or are lactating
2.Participants who, in the opinion of the investigator, do not understand the information and procedures of the study, or would not be compliant with them (in particular the study restrictions and risks involved).
3.Any participant for whom the investigator believes, for any reason, that participation would not be an acceptable risk.
4.Current use of MAOIs, thyroxine or stimulants (amphetamine/methyphenidate). Use of antidepressants or other anxiolytics at stable doses > 4 weeks is acceptable.
5.Patients with severe acute or chronic medical illnesses.
6.Patients with current active suicidal ideation.

Study design
Purpose of the study
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
In Phase 1 dosing will be sequential (lowest dose first, then ascending doses); in Phase 3 the most effective and best tolerated dose from Phase 1 will be used. There is no allocation concealment in Phases 1 and 3.

In Phase 2 dosing will be sequential (lowest ketamine dose first, then ascending doses), with a dose of midazolam (active control) randomly inserted within this sequence. Allocation concealment will be managed by having medication prepared by a pharmacist who is not involved with dosing or rating patients.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Phase 1/3 - n/a
Phase 2: computer generated random code
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Other design features
Phase 1 and Phase 3 have open label dosing. Blinding is only for Phase 2.
Phase 1 / Phase 2
Type of endpoint(s)
Pharmacokinetics / pharmacodynamics
Statistical methods / analysis
This is a pilot proof of concept study and subject numbers have been chosen pragmatically rather than based on statistical power considerations.

Changes in anxiety ratings will be modelled along with ketamine and metabolite blood concentrations, and changes in plasma BDNF levels

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] 6899 0
New Zealand
State/province [1] 6899 0

Funding & Sponsors
Funding source category [1] 291336 0
Self funded/Unfunded
Name [1] 291336 0
Address [1] 291336 0
Country [1] 291336 0
Primary sponsor type
University of Otago
PO Box 56
Dunedin, 9054
New Zealand
Secondary sponsor category [1] 290015 0
Name [1] 290015 0
Address [1] 290015 0
Country [1] 290015 0

Ethics approval
Ethics application status
Ethics committee name [1] 292899 0
NZ Health and Disability Ethics Committee
Ethics committee address [1] 292899 0
Ministry of Health
Ethics Department
Freyberg Building
Reception – Ground Floor
20 Aitken Street
Wellington 6011
Ethics committee country [1] 292899 0
New Zealand
Date submitted for ethics approval [1] 292899 0
Approval date [1] 292899 0
Ethics approval number [1] 292899 0

Brief summary
The glutamate antagonist ketamine has rapid onset antidepressant effects in patients with treatment-resistant depression. Patients with OCD and PTSD have had similarly rapid improvement in symptoms when administered ketamine. This study will assess if similar improvements occur in patients with GAD and SP.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 57550 0
Prof Paul Glue
Address 57550 0
Dunedin School of Medicine,
University of Otago
PO Box 913, Dunedin 9054
Country 57550 0
New Zealand
Phone 57550 0
64 3 470 3867
Fax 57550 0
64 3 474 7934
Email 57550 0
Contact person for public queries
Name 57551 0
Prof Paul Glue
Address 57551 0
Dunedin School of Medicine,
University of Otago
PO Box 913, Dunedin 9054
Country 57551 0
New Zealand
Phone 57551 0
64 3 470 3867
Fax 57551 0
64 3 474 7934
Email 57551 0
Contact person for scientific queries
Name 57552 0
Prof Paul Glue
Address 57552 0
Dunedin School of Medicine,
University of Otago
PO Box 913, Dunedin 9054
Country 57552 0
New Zealand
Phone 57552 0
64 3 470 3867
Fax 57552 0
64 3 474 7934
Email 57552 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
Pilot data
What supporting documents are/will be available?
No other documents available
Summary results
Have study results been published in a peer-reviewed journal?
Journal publication details
Publication date and citation/details [1] 2663 0
Glue P, Medlicott NJ, Harland S, Neehof S, Anderson-Fahey D, Le Nedelec M, Gray A, McNaughton N. Ketamine’s dose-related effects on anxiety symptoms in patients with treatment refractory anxiety disorders. J Psychopharmacol 2017, 13:1302-1305.
Attachments [1] 2663 0
Publication date and citation/details [2] 2718 0
Glue P, Neehoff SM, Medlicott NJ, Gray A, Kibby G, McNaughton N. Safety and efficacy of maintenance ketamine treatment in patients with treatment-refractory generalised anxiety and social anxiety disorders. J Psychopharmacol 2018, 32:663-7.
Attachments [2] 2718 0
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary
Low dose ketamine has dose-related anti-anxiety effects in patients with treatment refractory GAD/SAD. These effects can be maintained during 3 months of maintenance treatment.