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Trial registered on ANZCTR

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

Titles & IDs
Public title
The transition from acute to chronic post-surgical pain - a prospective, randomised controlled trial of two medications (nortriptyline and gabapentin) in 150 participants undergoing hip or knee replacement surgery.
Scientific title
A randomised control trial of the effectiveness of gabapentin and nortriptyline in the secondary prevention of chronic pain in 150 post-operative patients following hip and knee arthroplasty, as measured at three months post-operatively.
Secondary ID [1] 283877 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
The transition between acute and chronic post-surgical pain 290862 0
Condition category
Condition code
Anaesthesiology 291220 291220 0 0
Pain management

Study type
Description of intervention(s) / exposure
There are two pharmaceutical interventions which will be given simultaneously to the intervention group, as studies have shown these medications to have synergistic analgesic activity.

The first is gabapentin, which is a gamma-aminobutyric acid (GABA) analogue, which was developed as an anti-epileptic before becoming widely used in neuropathic pain. This medication is taken orally in three daily doses, and will be titrated up in increments of 300mg/day from 300mg to the maximum tolerated dose for an individual (usually in the range of 1800-2200mg/day, with 2200mg being the ceiling limit in this trial).

The other pharmaceutical being trialled is nortriptyline. Nortriptyline is a tri-cyclic antidepressant (TCA) which has recently come into vogue as a treatment for neuropathic pain. Nortriptyline will be taken orally once daily at the maximum tolerated dose for the individual (up to 50mg/day). Like gabapentin, this this dose will be titrated up over the course of 7-10 days, starting at 10mg/day.

Both of these medications will be taken by the intervention arm of this study between week 6 post-operatively and 3 months post-operatively (a total of 6 weeks).

The possible adverse effects will be explained to the participants in advance, and they will be given the opportunity to ask any questions they may have about the medications. Over the titration period, adherence will be monitored by telephone interviews with participants to monitor any adverse effects they may be experiencing. Participants will be instructed to return any unused medication to the researchers for disposal at the conclusion of their time in the trial.
Intervention code [1] 288551 0
Treatment: Drugs
Intervention code [2] 288552 0
Comparator / control treatment
Following discharge from hospital after these operations, there are no formal medical management pathways, save radiographic scans to check for implant wear rates and correct placement. Pain management following these surgeries typically involves the patient being discharged with short prescriptions for non-steroidal anti-inflammatories (such as paracetamol and ibuprofen), and opioid analgesics (such as codeine). There is, however, no formal clinical pathway for the management of pain in these individuals following discharge.
Control group

Primary outcome [1] 291214 0
Presence or absence of chronic pain, as determined by a pain score equal to or greater than 4 (out of 10) on a visual analogue scale.
Timepoint [1] 291214 0
Three (3) months post-operatively
Secondary outcome [1] 307148 0
Predicting post operative pain from baseline data, which will be collected by the multiple psychometric questionnaires conducted at baseline, the results of the cold pressor test, as well as the participants' relevant medical records. This will be tested by the same visual analogue scoring system as above,
Timepoint [1] 307148 0
Six (6) weeks post operatively
Secondary outcome [2] 307149 0
Predicting pain post operatively in the group receiving routine management. This will, as above, be measured by the visual analogue scale, and the potentially predictive tools will be the psychometric questionnaires, and the cold pressor test.
Timepoint [2] 307149 0
Three (3) months post operatively

Key inclusion criteria
17 years of age and over undergoing surgery for hip and knee arthroplasty at Burwood Public Hospital
Minimum age
17 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Those under 17 years of age
Those with cognitive impairments
Those currently receiving treatment with secondary analgesics

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Concealment done by random number generator on centralised computer
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using a randomisation table created by computer software
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Other design features
Phase 4
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Not yet recruiting
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] 5731 0
New Zealand
State/province [1] 5731 0

Funding & Sponsors
Funding source category [1] 288520 0
Name [1] 288520 0
University of Otago, Christchurch
Address [1] 288520 0
2 Riccarton Ave, Christchurch Central, Christchurch 8011
Country [1] 288520 0
New Zealand
Primary sponsor type
University of Otago, Christchurch
2 Riccarton Ave, Christchurch Central, Christchurch 8011
New Zealand
Secondary sponsor category [1] 287230 0
Name [1] 287230 0
Department of Anaesthesia, Pain Management Centre, Canterbury District Health Board
Address [1] 287230 0
Pain Management Centre, Burwood Public Hospital
Private Bag 4708
Christchurch 8140
Country [1] 287230 0
New Zealand

Ethics approval
Ethics application status
Ethics committee name [1] 290830 0
Health and Disability Ethics Committee
Ethics committee address [1] 290830 0
1 The Terrace, C/- MEDSAFE, Level 6 Deloitte Building, 10 Brandon Street, Wellington 6011
Ethics committee country [1] 290830 0
New Zealand
Date submitted for ethics approval [1] 290830 0
Approval date [1] 290830 0
Ethics approval number [1] 290830 0

Brief summary
This study aims to assess pre-operative factors which may contribute to the development of chronic post-surgical pain. In addition, two medications will be trialled to determine their efficacy in the prevention of chronic post-surgical pain.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 45382 0
Prof Edward Shipton
Address 45382 0
Department of Anaesthesia, University of Otago, Christchurch. PO Box 4345, Christchurch 8140
Country 45382 0
New Zealand
Phone 45382 0
+64 3 3641882
Fax 45382 0
Email 45382 0
Contact person for public queries
Name 45383 0
Prof Edward Shipton
Address 45383 0
Department of Anaesthesia, University of Otago, Christchurch. PO Box 4345, Christchurch 8140
Country 45383 0
New Zealand
Phone 45383 0
+64 3 3641882
Fax 45383 0
Email 45383 0
Contact person for scientific queries
Name 45384 0
Prof Edward Shipton
Address 45384 0
Department of Anaesthesia, University of Otago, Christchurch. PO Box 4345, Christchurch 8140
Country 45384 0
New Zealand
Phone 45384 0
+64 3 3641882
Fax 45384 0
Email 45384 0

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