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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
Type of registration
Prospectively registered

Titles & IDs
Public title
A study to investigate if melatonin can improve sleep in hospital after abdominal surgery.
Scientific title
Melatonin to Improve Sleep in Patients Undergoing Major Abdominal Surgery:
A Double-blind, Randomised Placebo-controlled Trial
Secondary ID [1] 300066 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Abdominal surgery 315585 0
Sleep disturbance 315586 0
Condition category
Condition code
Surgery 313871 313871 0 0
Other surgery
Alternative and Complementary Medicine 314059 314059 0 0
Other alternative and complementary medicine

Study type
Description of intervention(s) / exposure
Melatonin 5mg wafer once daily sublingual whilst in hospital from day 1 post surgery up to 7 days or until discharge if prior to 7 days. The doses will be prescribed via the electronic medication chart and this will be reviewed to confirm compliance to administration.
Intervention code [1] 316333 0
Treatment: Drugs
Comparator / control treatment
Placebo 1 wafer once daily sublingual whilst in hospital up to 7 days or until discharge if prior to 7 days. The placebo will consist of a starch.
Control group

Primary outcome [1] 322352 0
The primary efficacy outcome is a difference in Patient-Reported Outcome Measurement Information System (PROMIS) Sleep Disturbance 8a score between the 2 arms of the study.
Timepoint [1] 322352 0
At day 3 post surgery.
Secondary outcome [1] 378184 0
Mean difference between groups for serum cortisol levels
Timepoint [1] 378184 0
Levels measured at baseline, day of surgery and day 1, 2, 3 post-operatively as recorded from the medial record.
Secondary outcome [2] 378185 0
Incidence of post-operative surgical complications graded by the Clavien-Dindo Classification of Surgical Complications.
Timepoint [2] 378185 0
Up to day 30 post-op as recorded in medical record.
Secondary outcome [3] 378186 0
Difference between groups for mean length of hospital stay (days)
Timepoint [3] 378186 0
As recorded in medical record for index admission, up to the time of suitability for surgical discharge to home or rehabilitation.
Secondary outcome [4] 378187 0
All-cause mortality
Timepoint [4] 378187 0
By day 30 as recorded in medical record or reported by treating surgeon.
Secondary outcome [5] 378188 0
Incidence of delirium as defined by a clinical diagnosis of same by treating team.
Timepoint [5] 378188 0
Assessed from the medical record up to the time of hospital discharge or discharge from surgical service.
Secondary outcome [6] 378189 0
Patient reported quality of life scores
Timepoint [6] 378189 0
Measured pre-operatively and at day 30 post-op using the EQ-5D-5L.

Key inclusion criteria
All English-speaking patients 18 years and over undergoing elective/semi-elective major abdominal surgery with an anticipated length of stay greater than 48 hours.
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Patients from the above group will be excluded if they:
• Are unable to give written informed consent to take part in the study,
• Patients who require the use of a trained healthcare interpreter to be able to understand study information.
• Lack decision-making capacity,
• Expected stay less than 48 hours,
• Concurrent use of benzodiazepine, non-benzodiazepine (Z-drugs) or melatonin,
• Alcohol consumption > 13 units/week for women and >20 units/week for men.
• Currently taking melatonin
• Drug interaction with melatonin.
• Allergy to melatonin or its excipients (may contain lactose)
• Decreased renal function as defined by an eGFR of <30 mL/min/1.73m2
• Decreased liver function defined as an AST > 500 U/L or ALT >500 U/L
• Pregnant or breastfeeding females
• Enrolment in other clinical trials involving an investigational agent
• Taking quinolones, carbamazepine and rifampicin, fluvoxamine, 5- or 8- methoxypsoralen, cimetidine, oestrogens.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Central randomisation by computer
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Permuted block randomisation
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 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 in Australia
Recruitment state(s)
Recruitment hospital [1] 15529 0
John Hunter Hospital - New Lambton
Recruitment postcode(s) [1] 28899 0
2305 - New Lambton

Funding & Sponsors
Funding source category [1] 304515 0
Name [1] 304515 0
John Hunter Hospital
Address [1] 304515 0
Lookout Road
New Lambton Heights NSW 2305
Country [1] 304515 0
Primary sponsor type
Government body
Hunter New England Local Health District.
Lookout Road
New Lambton Heights NSW 2305
Secondary sponsor category [1] 304784 0
Name [1] 304784 0
Address [1] 304784 0
Country [1] 304784 0

Ethics approval
Ethics application status
Ethics committee name [1] 304946 0
Hunter New England Human Research Ethics Committee
Ethics committee address [1] 304946 0
Locked Bag 1
New Lambton NSW 2305
Ethics committee country [1] 304946 0
Date submitted for ethics approval [1] 304946 0
Approval date [1] 304946 0
Ethics approval number [1] 304946 0

Brief summary
The primary purpose of this project is to determine whether the use of melatonin improves the quality of sleep in patients undergoing major abdominal surgery. Melatonin is a natural hormone secreted by the pineal gland. Melatonin when given at night works to promote sleep by helping to regulate the body's bio clock and sleep-wake cycles. It is well known that sleep quality in hospital is poor and can cause insufficient sleep which reduces natural immune function. Major abdominal surgery leads to the release of both pro-inflammatory and anti-inflammatory chemical in the blood.. Melatonin could be an effective adjunct medication not only to assist in improving sleep but to dampen the inflammatory response after surgery.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 98726 0
Dr Eduard Martinez
Address 98726 0
Intensive Care Unit
John Hunter Hospital
Locked Bag 1
Hunter Region Mail Centre NSW 2310
Country 98726 0
Phone 98726 0
+61 0249236397
Fax 98726 0
Email 98726 0
Contact person for public queries
Name 98727 0
Ms Rosemary Carroll
Address 98727 0
Surgical Services
John Hunter Hospital
Locked Bag 1
Hunter Region Mail Centre NSW 2310
Country 98727 0
Phone 98727 0
+61 2 4923 6397
Fax 98727 0
Email 98727 0
Contact person for scientific queries
Name 98728 0
Dr Eduard Martinez
Address 98728 0
Intensive Care Unit
John Hunter Hospital
Locked Bag 1
Hunter Region Mail Centre NSW 2310
Country 98728 0
Phone 98728 0
+61 0249236397
Fax 98728 0
Email 98728 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
Undecided as yet.
What supporting documents are/will be available?
No other documents available
Summary results
No Results