Ensuring the safety of new medications and devices: are naltrexone implants safe?

Alex D Wodak, Robert Ali, David Henry and Lloyd Sansom
Med J Aust 2008; 188 (8): . || doi: 10.5694/j.1326-5377.2008.tb01711.x
Published online: 21 April 2008

Naltrexone implants have not been subject to the usual rigorous scrutiny required for new devices in Australia, but are widely used through the Special Access Scheme

In this issue of the Journal, Lintzeris and colleagues report eight patients with naltrexone implants who developed serious medical complications considered to be related to the implant (→ Unplanned admissions to two Sydney public hospitals after naltrexone implants).1 Intuitively, naltrexone is an attractive treatment for opioid dependence, as it is inexpensive, long-acting and generally well tolerated, and blocks the actions of heroin when taken orally. However, empirical support for naltrexone has been unimpressive,2-4 with research showing that poor adherence to treatment limits its effectiveness. An Australian study found that, while patients who adhered to treatment did well, only 2% were still taking the drug 3 months after conventional inpatient detoxification.5

  • 1 Alcohol and Drug Service, St Vincent’s Hospital, Sydney, NSW.
  • 2 Discipline of Pharmacology, School of Medical Sciences, University of Adelaide, Adelaide, SA.
  • 3 School of Medicine and Public Health, University of Newcastle, Newcastle, NSW.
  • 4 Division of Health Science, University of South Australia, Adelaide, SA.


Competing interests:

Robert Ali received an untied educational grant from Reckitt Benckiser to convene an annual scientific meeting in Asia. All funds were used for travel, accommodation and living expenses for himself and delegates.

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