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Trial registered on ANZCTR


Registration number
ACTRN12605000479606
Ethics application status
Approved
Date submitted
15/09/2005
Date registered
23/09/2005
Date last updated
11/09/2007
Type of registration
Prospectively registered

Titles & IDs
Public title
Individual Medication Effectiveness Tests (IMETs) to assess the efficacy of gabapentin in individual patients with chronic neuropathic pain.
Scientific title
Individual Medication Effectiveness Tests (IMETs) to assess the efficacy of gabapentin in individual patients with chronic neuropathic pain.
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Neuropathic pain. 600 0
Condition category
Condition code
Neurological 673 673 0 0
Other neurological disorders

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
This single patient (n of 1) IMET is a randomised, double-blind, cross-over comparison of gabapentin and placebo within an individual patient. We will do an initial open label trial to see if gabapentin is effective, and for dose finding. Once the dose has been decided (see medication section), we will use two week treatment periods, with measurement in the second week, allowing for wash out. There will be 3 pairs of 2 week treatment periods, making a total of twelve weeks. The order of drugs in each cycle will be determined by random allocation. The choice of initial therapy will be balanced in blocks of four, to ensure that equivalent numbers start the IMET on each of the two drugs. Patients and practitioners will all be blinded to which treatment the patients are taking. Product information about gabapentin will be provided to the patient at the beginning of the study. The patient will keep careful track of their symptoms by recording them in a special diary. If at any time during the study the patient feels worse, that treatment period can be terminated, and they can go on to the next treatment period. Upon the completion of the study, the timing of the active treatment will be revealed. After looking at the symptoms recorded, the doctor and patient decide together whether gabapentin was of greater benefit than placebo. If the patient chooses, they can then continue on the drug, confident that it is effective.
Intervention code [1] 622 0
Treatment: Drugs
Comparator / control treatment
Placebo
Control group
Placebo

Outcomes
Primary outcome [1] 804 0
To assess activities of daily living.

Descriptive information to be collected on each patient includes age, sex, duration of chronic pain, previous therapy, type of neuropathic pain, what areas are affected, and concomitant pain therapy. Each patient will complete:
- A prestudy questionnaire. The patients will nominate a maximum of four activities from the questionnaire that are most affected by their pain. Where several areas may be a problem, the patients will be asked to nominate one most severely affected (marker) area. If this is not possible, they will be asked to make global ratings of their pain.
Timepoint [1] 804 0
Prestudy and at entry.
Primary outcome [2] 805 0
The degree of patient confidence in the efficacy of their current pain medication will be assessed.

Descriptive information to be collected on each patient includes age, sex, duration of chronic pain, previous therapy, type of neuropathic pain, what areas are affected, and concomitant pain therapy. Each patient will complete:
- A prestudy questionnaire. The patients will nominate a maximum of four activities from the questionnaire that are most affected by their pain. Where several areas may be a problem, the patients will be asked to nominate one most severely affected (marker) area. If this is not possible, they will be asked to make global ratings of their pain.
Timepoint [2] 805 0
Prestudy and at entry.
Primary outcome [3] 806 0
Monitoring participants' sleep on visual analogue scales.

Descriptive information to be collected on each patient includes age, sex, duration of chronic pain, previous therapy, type of neuropathic pain, what areas are affected, and concomitant pain therapy. Each patient will complete:
- A symptom diary consisting of:
* A daily estimation of the degree of pain in the marker area, on visual analogue scales. Patients will be asked to summarise their day's pain at the time of their evening meal/medication (or other preferred time).
Timepoint [3] 806 0
Monitored on a daily basis.
Primary outcome [4] 807 0
Descriptive information to be collected on each patient includes age, sex, duration of chronic pain, previous therapy, type of neuropathic pain, what areas are affected, and concomitant pain therapy. Each patient will complete:
- A symptom diary consisting of:
* A weekly check-list of side effects and adverse events, enquiring whether symptoms have been experienced and, if so, rating the severity of the symptom.
Timepoint [4] 807 0
Monitored on weekly basis.
Primary outcome [5] 808 0
Descriptive information to be collected on each patient ncludes age, sex, duration of chronic pain, previous therapy, type of neuropathic pain, what areas are affected, and concomitant pain therapy. Each patient will complete:
- A symptom diary consisting of:
* A weekly checklist of escape analgesia used.
Timepoint [5] 808 0
Monitored on weekly basis.
Primary outcome [6] 809 0
Descriptive information to be collected on each patient includes age, sex, duration of chronic pain, previous therapy, type of neuropathic pain, what areas are affected, and concomitant pain therapy. Each patient will complete:
- A symptom diary consisting of:
* A weekly global assessment of how they felt, with respect to their pain, in comparison with their usual symptoms, including any change in the activities most affected by their pain.
Timepoint [6] 809 0
Monitored on weekly basis.
Primary outcome [7] 810 0
Descriptive information to be collected on each patient includes age, sex, duration of chronic pain, previous therapy, type of neuropathic pain, what areas are affected, and concomitant pain therapy. Each patient will complete:
- A symptom diary consisting of:
* A final questionnaire to assess the amount of benefit they felt they obtained from the medication trialled, and their degree of certainty about that assessment.
Timepoint [7] 810 0
Primary outcome [8] 811 0
Pill-counts to monitor participants' compliance with the trial medication.
Timepoint [8] 811 0
On a monthly basis.
Primary outcome [9] 812 0
The attending doctor will complete an initial questionnaire to assess the degree of certainty they have about the amount of benefit they currently believe the patient obtains from gabapentin (if applicable), and their degree of certainty about that assessment.
Timepoint [9] 812 0
Primary outcome [10] 813 0
The attending doctor will complete a post-IMET questionnaire, to assess any changes in treatment plan and their degree of certainty about the benefit of gabapentin to the patient.
Timepoint [10] 813 0
Secondary outcome [1] 1624 0
We will monitor prescribing of gabapentin in the clinics from where patients are recruited, and the costs to patients and the hospital of baseline gabapentin consumption and gabapentin consumption following the IMET for each patient.
Timepoint [1] 1624 0
Secondary outcome [2] 1625 0
We will also document the cost of providing the IMET. This will allow cost effectiveness of the IMETs to be calculated.
Timepoint [2] 1625 0

Eligibility
Key inclusion criteria
Any adult patient with a clinical diagnosis of chronic neuropathic pain, defined as pain due to damage or dysfunction involving the peripheral or central nervous systems, and including phantom limb pain, poststroke pain, causalgia, postherpetic neuralgia, diabetic neuropathy, trigeminal neuralgia, and complex regional pain syndrome. Pain needs to be of at least 3 months' duration, of sufficient severity to warrant consideration of long-term gabapentin use, in the opinion of the attending medical practitioner. Many such patients may already be on gabapentin.
Minimum age
18 Years
Maximum age
Not stated
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Previous sensitivity to gabapentin, patients with a history of seizure, pregnancy, renal impairment (creatinine clearance < 30 mls/min), certain H2 antagonists.

Study design
Purpose of the study
Treatment
Allocation to intervention
Non-randomised 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
Blinded (masking used)
Who is / are masked / blinded?



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

Recruitment
Recruitment status
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 in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 742 0
Government body
Name [1] 742 0
Australian Health Ministers' Advisory Council
Address [1] 742 0
Country [1] 742 0
Australia
Funding source category [2] 743 0
Hospital
Name [2] 743 0
Princess Alexandra Hospital
Address [2] 743 0
Country [2] 743 0
Australia
Funding source category [3] 744 0
Hospital
Name [3] 744 0
Port Kembla Hospital
Address [3] 744 0
Country [3] 744 0
Australia
Primary sponsor type
University
Name
University of Queensland
Address
Country
Australia
Secondary sponsor category [1] 615 0
Hospital
Name [1] 615 0
Princess Alexandra Hospital, Brisbane
Address [1] 615 0
Country [1] 615 0
Australia
Secondary sponsor category [2] 616 0
Hospital
Name [2] 616 0
Port Kembla Hospital, NSW
Address [2] 616 0
Country [2] 616 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 1963 0
University of Queensland
Ethics committee address [1] 1963 0
Ethics committee country [1] 1963 0
Australia
Date submitted for ethics approval [1] 1963 0
Approval date [1] 1963 0
Ethics approval number [1] 1963 0
Ethics committee name [2] 1964 0
Princess Alexandra Hospital
Ethics committee address [2] 1964 0
Ethics committee country [2] 1964 0
Australia
Date submitted for ethics approval [2] 1964 0
Approval date [2] 1964 0
Ethics approval number [2] 1964 0
Ethics committee name [3] 1965 0
Port Kembla Hospital
Ethics committee address [3] 1965 0
Ethics committee country [3] 1965 0
Australia
Date submitted for ethics approval [3] 1965 0
Approval date [3] 1965 0
Ethics approval number [3] 1965 0

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 36175 0
Address 36175 0
Country 36175 0
Phone 36175 0
Fax 36175 0
Email 36175 0
Contact person for public queries
Name 9811 0
Norma McNairn
Address 9811 0
Individualised Medication Effectiveness Test (IMET) Service
University of Queensland
Level 2
Edith Cavell Building
Herston QLD 4006
Country 9811 0
Australia
Phone 9811 0
+61 7 33464835
Fax 9811 0
+61 7 33655130
Email 9811 0
n.mcnairn@uq.edu.au
Contact person for scientific queries
Name 739 0
Associate Professor Michael Yelland
Address 739 0
Department of Primary Health Care
School of Medicine
Griffith University
Logan Campus
University Drive
Meadowbrook QLD 4131
Country 739 0
Australia
Phone 739 0
+61 7 33821358
Fax 739 0
+61 7 33821338
Email 739 0
m.yelland@griffith.edu.au

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