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Trial registered on ANZCTR


Registration number
ACTRN12609000032257
Ethics application status
Approved
Date submitted
24/11/2008
Date registered
19/01/2009
Date last updated
5/04/2017
Type of registration
Retrospectively registered

Titles & IDs
Public title
Does taking the drug thyroxine on an empty stomach or with food significantly alter its absorption in treating patients with hypothyroidism?
Scientific title
Does taking the drug thyroxine on an empty stomach or with food significantly alter its absorption in treating patients with hypothyroidism?
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Absorption of the drug thyroxine in patients with hypothyroidism 4009 0
Condition category
Condition code
Metabolic and Endocrine 4212 4212 0 0
Thyroid disease

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Participants who are taking a standard oral dose of the thyroxine tablet manufactured by GlaxoSmithKline (brand name: Eltroxin) will take their thyroxine tablet orally with food (their meal). Their dosage amount will continue to be what has been their regular dose previous to the commencement of the study as prescribed by their General Practitioner, therefore each patient will be taking an individualised dosage amount between 0.05mg - 0.20mg; dosage frequency will be once daily with food. As approximately six to eight weeks is required for any changes in thyroid function (i.e. changes in blood Thyroid Stimulating Hormone levels) to be seen, the duration of the Intervention Treatment for each participant will be six to eight weeks.
Intervention code [1] 3735 0
Treatment: Drugs
Comparator / control treatment
As this is a crossover study, participants will be acting as their own control. Control treatment is active: Participants will take their thyroxine tablet orally on an empty stomach (at least thirty minutes before their meal). Their dosage amount will continue to be what has been their regular dose previous to the commencement of the study as prescribed by their General Practitioner, therefore each patient will be taking an individualised dosage amount between 0.05mg - 0.20mg; dosage frequency will be once daily with food. A 'wash-out' period of 1 day will be given between Intervention and Control Treatments. As approximately six to eight weeks is required for any changes in thyroid function (i.e. changes in blood Thyroid Stimulating Hormone levels) to be seen, the duration of the Control Treatment for each participant will be six to eight weeks.
Control group
Active

Outcomes
Primary outcome [1] 5106 0
Blood Thyroid Stimulating Hormone (TSH) level outside the normal range of 0.3 - 4.0mu/L. A blood sample (approximately 5mLs) will be taken from each participant and sent to the Biochemistry Laboratory where TSH level in the blood sample will be measured.
Timepoint [1] 5106 0
at baseline; at eight weeks after beginning Intervention Treatment; and at eight weeks after beginning Control Treatment.
Secondary outcome [1] 8600 0
Weight. Each participant's weight will be measured by the health care professionals conducting this research in our clinic here in the hospital.
Timepoint [1] 8600 0
at baseline; at eight weeks after beginning Intervention Treatment; and at eight weeks after beginning Control Treatment.
Secondary outcome [2] 8601 0
Heart Rate. Each participant's heart rate will be measured by the health care professionals conducting this research in our clinic here in the hospital.
Timepoint [2] 8601 0
at baseline; at eight weeks after beginning Intervention Treatment; and at eight weeks after beginning Control Treatment.
Secondary outcome [3] 8602 0
Blood Pressure. Each participant's blood pressure will be measured by the health care professionals conducting this research in our clinic here in the hospital.
Timepoint [3] 8602 0
at baseline; at eight weeks after beginning Intervention Treatment; and at eight weeks after beginning Control Treatment.

Eligibility
Key inclusion criteria
Participant: has been taking thyroxine tablets for hypothyroidism for a minimum of 8 weeks; thyroxine tablet taken is manufactured by GlaxoSmithKline (brand name: Eltroxin); takes a standard daily dose; >18 years; has a blood TSH level within the normal range of 0.4 – 4.0mu/L at the start of study
Minimum age
18 Years
Maximum age
Not stated
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Participant: has history of other serious illness, for example active cardiovascular disease; is normally non-compliant with medication; is currently taking other medications that could possibly interfere with thyroxine absorption, for example omeprazole, or calcium tablets; has a blood TSH level not within the normal range of 0.4 – 4.0mu/L at the start of the study

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Who is / are masked / blinded?



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

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment outside Australia
Country [1] 1398 0
New Zealand
State/province [1] 1398 0

Funding & Sponsors
Funding source category [1] 4199 0
University
Name [1] 4199 0
University of Otago, Department of Medical and Surgical Sciences
Address [1] 4199 0
Department of Medical and Surgical Sciences
Dunedin Public Hospital
201 Great King Street
Dunedin 9016
Country [1] 4199 0
New Zealand
Primary sponsor type
Individual
Name
Associate Professor Dr Patrick Manning
Address
Endocrinology Research Unit
Dunedin Public Hospital
201 Great King Street
Dunedin 9016
Country
New Zealand
Secondary sponsor category [1] 3773 0
Individual
Name [1] 3773 0
Ahrin Anna Choi
Address [1] 3773 0
Endocrinology Research Unit
Dunedin Public Hospital
201 Great King Street
Dunedin 9016
Country [1] 3773 0
New Zealand

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 6257 0
Lower South Regional Ethics Committee
Ethics committee address [1] 6257 0
Ministry of Health
Level 4
229 Moray Place
PO Box 5849
Dunedin 9016
Ethics committee country [1] 6257 0
New Zealand
Date submitted for ethics approval [1] 6257 0
28/10/2008
Approval date [1] 6257 0
10/11/2008
Ethics approval number [1] 6257 0
LRS/08/11/060

Summary
Brief summary
Hypothyroidism is one of the most common endocrine disorders, the treatment of which consists of lifelong replacement therapy with the drug thyroxine. Drug company GlaxoSmithKline recently reformulated their thyroxine tablet and now requires the tablet be taken on an empty stomach. To our knowledge however there is no evidence currently to suggest that food affects gastrointestinal thyroxine absorption. As taking medications on an empty stomach makes patient compliance more difficult this project aims to show that taking thyroxine with food will not affect its absorption in any clinically significant manner.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 29156 0
Address 29156 0
Country 29156 0
Phone 29156 0
Fax 29156 0
Email 29156 0
Contact person for public queries
Name 12313 0
Ahrin Anna Choi
Address 12313 0
Endocrinology Research Unit
Dunedin Public Hospital
201 Great King Street
Dunedin 9016
Country 12313 0
New Zealand
Phone 12313 0
+64 3 4747733
Fax 12313 0
Email 12313 0
choah986@student.otago.ac.nz
Contact person for scientific queries
Name 3241 0
Associate Professor Dr Patrick Manning
Address 3241 0
Endocrinology Research Unit
Dunedin Public Hospital
201 Great King Street
Dunedin 9016
Country 3241 0
New Zealand
Phone 3241 0
+64 3 4747733
Fax 3241 0
Email 3241 0
patrick.manning@otagodhb.govt.nz

No information has been provided regarding IPD availability
Summary results
No Results