Trial registered on ANZCTR

Trial ID
Ethics application status
Date submitted
Date registered
Type of registration
Retrospectively registered

Titles & IDs
Public title
A randomised double blind placebo controlled clinical trial of the efficacy of an Australian naltrexone implant compared to oral naltrexone for the long-term management of heroin-dependent persons
Study title in 'Participant- Intervention- Comparator- Outcome (PICO)' format
A randomised double blind placebo controlled clinical trial of naltrexone implants for the treatment of heroin addiction
Universal Trial Number (UTN)
Trial acronym

Health condition
Health condition(s) or problem(s) studied:
Heroin dependence 1279 0
Condition category
Condition code
Mental Health 1366 1366 0 0

Study type
Description of intervention(s) / exposure
A randomised, double placebo, double blind trial comparing the O’Neil long acting naltrexone subcutaneous implant (3.6g release rate 0.4% / day) plus placebo capsule with placebo implant plus capsules containing 50mg naltrexone hydrochloride. Participants will receive the intervention and data will be collected for a total of 6 months.
Intervention code 1203 0
Treatment: drugs
Comparator / control treatment
Double Placebo
Control group

Primary outcome 1867 0
Proportion with blood naltrexone concentrations above therapeutic levels (2 ng/ml)
Timepoint 1867 0
Measured at 1, 2, 3, 4, 5, & 6 months
Primary outcome 1868 0
Number of accidental opiate overdoses (hospital admissions or ED presentations) to 6 months
Timepoint 1868 0
baseline to 6 months
Secondary outcome 3284 0
Opiate related morbidity (hospital admissions) and mortality to 6 months
Timepoint 3284 0
baseline to 6 months
Secondary outcome 3285 0
Craving for heroin questionnaire (Tiffany).
Timepoint 3285 0
Measured at 0, 1, 2, 3, 4, 5, & 6 months.
Secondary outcome 3286 0
Proportion returning to dependent heroin/opiate use (DSM IV criteria).
Timepoint 3286 0
At 6 months.
Secondary outcome 3287 0
Frequency of other drug use.
Timepoint 3287 0
At 0, 1, 2, 3, 4, 5, & 6 months.
Secondary outcome 3288 0
Other drug related accidental overdose, other morbidity (hospital admission or ED presentation) or mortality to 6 months
Timepoint 3288 0
baseline to 6 months
Secondary outcome 3289 0
Opiate Treatment Index scores.
Timepoint 3289 0
At 0, 1, 2, 3, 4, 5, & 6 months.

Key inclusion criteria
Heroin dependence (DSM-IV criteria which covers the previous 12 months)Resident in the Perth (Western Australia) metropolitan area or regional areas with approved study support services Willing and able to provide written informed consentWilling to be randomised to either arm of the studySatisfactory completion of screening questionnaire.
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
High risk of overdose (3+ overdoses in previous month)Non compliant with oral naltrexone (4 + times in last 3 months) or prior implantPregnancyContra indications or prior adverse reactions for study medications/procedures.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Numbered containers
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Randomisation was based on computer generated random numbers, using a variable block size with a unified allocation ratio
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Phase 2
Type of endpoint(s)

Anticipated date of first participant enrolment
Actual date of first participant enrolment
Anticipated date last participant enrolled
Actual date last participant enrolled
Target sample size
Actual sample size
Recruitment status
Closed: follow-up complete
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category 1501 0
Government body
Name 1501 0
National Health & Medical Research Council
Address 1501 0
Country 1501 0
Primary sponsor
Primary sponsor name
University of Western Australia
Primary sponsor address
35 Stirling Highway
Primary sponsor country
Secondary sponsor category 1318 0
Name 1318 0
Address 1318 0
Country 1318 0

Ethics approval
Ethics application status
Ethics committee name 2923 0
University of Western Australia HREC
Ethics committee address 2923 0
35 Stirling Highway,
Ethics committee country 2923 0
Date submitted for ethics approval 2923 0
Approval date 2923 0
Ethics approval number 2923 0

Brief summary
GoMedical Industries has developed a formulation of sustained release naltrexone, suitable for subcutaneous depot administration. Currently, implants are inserted by minor surgery under local anaesthetic in high risk patients under the Therapeutic Goods Administration (TGA) Special Access Category A scheme (SAS) through the Australian Medical Procedures Research Foundation (AMPRF), Western Australia. Although there is a preliminary basis for believing that this naltrexone implant treatment may offer significant benefits over oral and other naltrexone depot preparations thus far reported for managing the heroin dependent patient, this needs to be verified through a clinical trial. Hence, the main objective of this study is to provide rigorous clinical data using a double blind, double placebo controlled study, on the effectiveness of this naltrexone implant compared to oral naltrexone in the management of heroin dependent persons by primarily monitoring: maintenance of blood naltrexone and 6-b-naltrexol concentrations above therapeutic levels; prevention of accidental opiate overdose; reduced opiate use; reduced opiate related morbidity and mortality; reduced craving for heroin and other health related outcomes.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 35302 0
Address 35302 0
Country 35302 0
Phone 35302 0
Fax 35302 0
Email 35302 0
Contact person for public queries
Name 10392 0
Dr Robert Tait
Address 10392 0
School of Psychiatry & Clinical Neurosciences,
University of Western Australia,
QE II Medical Centre, MPC 521,
Nedlands, Perth SA
Country 10392 0
Phone 10392 0
+61 8 9346 2281
Fax 10392 0
+61 8 9346 3828
Email 10392 0
Contact person for scientific queries
Name 1320 0
Professor Gary Hulse
Address 1320 0
School of Psychiatry & Clinical Neurosciences
University of Western Australia
QE II Medical Centre MPC 521
Nedlands Perth
Country 1320 0
Phone 1320 0
+61 8 9346 2280
Fax 1320 0
+61 8 9346 3828
Email 1320 0