Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12616001227482
Ethics application status
Approved
Date submitted
31/08/2016
Date registered
5/09/2016
Date last updated
22/08/2017
Type of registration
Prospectively registered

Titles & IDs
Public title
Thyroid tests in people who are taking quetiapine.
Scientific title
The effect of quetiapine on thyroid function test results measured by both immunoassay and LCMSMS
Secondary ID [1] 289978 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record
ACTRN registration number 12616001242415

Health condition
Health condition(s) or problem(s) studied:
Mental health disorders 299984 0
Schizophrenia 300168 0
Bipolar disorder 300169 0
Anxiety 300170 0
Condition category
Condition code
Mental Health 299877 299877 0 0
Schizophrenia
Mental Health 300059 300059 0 0
Anxiety
Mental Health 300060 300060 0 0
Other mental health disorders

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
Collection of one blood specimen from 20 people who are already taking quetiapine.
The specimen will be 7.5 millilitres, or about one and a half teaspoons volume.
Thyroid function and quetiapine will be measured in the specimens.
Intervention code [1] 295800 0
Diagnosis / Prognosis
Comparator / control treatment
No control group
Control group
Uncontrolled

Outcomes
Primary outcome [1] 299501 0
Comparison of Free T4 levels as measured by immunoassay and LC-MSMS.
Timepoint [1] 299501 0
One visit only, for one blood specimen
Primary outcome [2] 299526 0
Comparison of Free T3 levels as measured by immunoassay and LC-MSMS.
Timepoint [2] 299526 0
One visit only, for one blood specimen
Secondary outcome [1] 327353 0
Quetiapine concentration as a predictor of immunoassay - LCMSMS assay difference in a mixed effects model.
Timepoint [1] 327353 0
One visit only
Secondary outcome [2] 327453 0
Exploratory outcome: relationships between immunoassay - LCMSMS assay difference and total T3, T4, TSH and anti-thyroid antibodies.
Timepoint [2] 327453 0
One blood specimen only, one visit

Eligibility
Key inclusion criteria
20 patients who are have been taking quetiapine on a daily basis for at least one month.
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
No exclusion criteria.

Study design
Purpose
Natural history
Duration
Longitudinal
Selection
Defined population
Timing
Prospective
Statistical methods / analysis
For the primary outcome measures (fT3 and fT4), we will make pairwise comparisons of data employing t- or z-testing. If the immunoassay and LCMSMS assay are shown to return systematically different values, an exploratory analysis will follow to estimate the effect of quetiapine concentration as a covariate in multiple regression.
There are no estimates available for the mean and variance of the immunoassay-LCMSMS difference. A power calculation that is based on comparison of immunoassay results in a recruited quetiapine-treated population to the known general population characteristics (the laboratory’s calculated normal value distribution) for fT4 was done, to get an upper estimate for numbers required to demonstrate a clinically meaningful difference.
The laboratory range for fT4 (9 -19 pmol/L) includes values within 2sd below and above the population mean, implying that mean = 14 and sd = 2.5 pm/L. A clinically significant difference in fT4 is 2.5 pmol/L. Assuming that the sample standard deviation = mean and taking fT4 to be a continuous variable, a sample of 16 patients will give at 80% power to detect the clinically relevant difference of 2.5 pm/L in fT4 at alpha = 0.05, 2-tailed. The study of 20 patients should therefore give a sufficiently precise estimate of the mean difference, particularly since paired comparisons, rather than unpaired comparisons, will be possible. The resulting data will then allow a decision on whether to proceed to a subsequent phase of this study program, which is to examine changes in fT4 over time. .

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
30/09/2017
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
20
Accrual to date
0
Final
Recruitment in Australia
Recruitment state(s)
WA
Recruitment hospital [1] 6601 0
Sir Charles Gairdner Hospital - Nedlands
Recruitment postcode(s) [1] 14208 0
6009 - Nedlands

Funding & Sponsors
Funding source category [1] 294439 0
Government body
Name [1] 294439 0
PathWest Laboratory Medicine
Country [1] 294439 0
Australia
Primary sponsor type
Government body
Name
PathWest Laboratory Medicine
Address
PathWest Laboratory Medicine,
Locked Bag 2009,
Nedlands, WA 6009
Country
Australia
Secondary sponsor category [1] 293292 0
None
Name [1] 293292 0
Address [1] 293292 0
Country [1] 293292 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 295869 0
Sir Charles Gairdner Hospital Human Research Ethics Committee
Ethics committee address [1] 295869 0
Sir Charles Gairdner Hospital Human Research Ethics Committee;
2nd Floor, "A" Block,
QEII Medical Centre,
Nedlands, WA 6009
Ethics committee country [1] 295869 0
Australia
Date submitted for ethics approval [1] 295869 0
01/05/2016
Approval date [1] 295869 0
19/08/2016
Ethics approval number [1] 295869 0
2015-169

Summary
Brief summary
Quetiapine is a commonly-prescribed drug with a good safety margin that is prescribed in psychotic illnesses, agitation and anxiety. Thyroid function is commonly checked in patients with psychotic disorders and signs of anxiety. We have observed that some patients taking quetiapine have low results on measure of free thyroid hormone level in blood, even though there is no other evidence that their thyroid function is impaired. We suspect this is because the quetiapine is interfering with the laboratory test, but it might actually be a biological effect of the quetiapine and potentially important to quetiapine’s adverse effects on metabolism.
In this project, we will first ask 20 patients who are already taking quetiapine to provide us with one specimen of blood each to check thyroid function.
In a subsequent part of the study (which has a different registration on the ANZ Clinical Trials Registry), we will also ask a further 20 patients in whom their treating psychiatrist has already made the clinical decision to commence quetiapine as part of their management plan, to provide us with a specimen of blood to check thyroid function on 4 occasions (prior to quetiapine commencement, 1 day following commencement of quetiapine, and at weeks 3 and 6 ).
We will firstly check to see whether our impression, that free thyroid hormone tests are reading lower in patients on quetiapine by the current test, is correct. The current test is an immunoassay. Then we will use the same blood specimens to measure free thyroid hormone level by another newer, highly specific test (LCMSMS) that is not open to interference in the way immunoassays may be. A comparison of the results will tell us whether the problem is simply immunoassay interference from quetiapine.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 68410 0
Dr Rhonda Maguire
Address 68410 0
Department of Clinical Pharmacology & Toxicology,
PathWest Laboratory Medicine,
Locked Bag 2009,
Nedlands, WA 6009
Country 68410 0
Australia
Phone 68410 0
+618 63834151
Fax 68410 0
Email 68410 0
[email protected]
Contact person for public queries
Name 68411 0
Dr Rhonda Maguire
Address 68411 0
Department of Clinical Pharmacology & Toxicology,
PathWest Laboratory Medicine,
Locked Bag 2009,
Nedlands, WA 6009
Country 68411 0
Australia
Phone 68411 0
+618 63834151
Fax 68411 0
Email 68411 0
[email protected]
Contact person for scientific queries
Name 68412 0
Dr Rhonda Maguire
Address 68412 0
Department of Clinical Pharmacology & Toxicology,
PathWest Laboratory Medicine,
Locked Bag 2009,
Nedlands, WA 6009
Country 68412 0
Australia
Phone 68412 0
+618 63834151
Fax 68412 0
Email 68412 0
[email protected]

No information has been provided regarding IPD availability


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No Supporting Document Provided



Results publications and other study-related documents

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