New aspects in the treatment of heroin dependence with special reference to neurobiological aspects

Diacetylmorphine versus methadone for the treatment of opioid addiction

BACKGROUND

Studies in Europe have suggested that injectable diacetylmorphine, the active ingredient in heroin, can be an effective adjunctive treatment for chronic, relapsing opioid dependence.

METHODS

In an open-label, phase 3, randomized, controlled trial in Canada, we compared injectable diacetylmorphine with oral methadone maintenance therapy in patients with opioid dependence that was refractory to treatment. Long-term users of injectable heroin who had not benefited from at least two previous attempts at treatment for addiction (including at least one methadone treatment) were randomly assigned to receive methadone (111 patients) or diacetylmorphine (115 patients). The primary outcomes, assessed at 12 months, were retention in addiction treatment or drug-free status and a reduction in illicit-drug use or other illegal activity according to the European Addiction Severity Index.

RESULTS

The primary outcomes were determined in 95.2% of the participants. On the basis of an intention-to-treat analysis, the rate of retention in addiction treatment in the diacetylmorphine group was 87.8%, as compared with 54.1% in the methadone group (rate ratio for retention, 1.62; 95% confidence interval [CI], 1.35 to 1.95; P<0.001). The reduction in rates of illicit-drug use or other illegal activity was 67.0% in the diacetylmorphine group and 47.7% in the methadone group (rate ratio, 1.40; 95% CI, 1.11 to 1.77; P=0.004). The most common serious adverse events associated with diacetylmorphine injections were overdoses (in 10 patients) and seizures (in 6 patients).

CONCLUSIONS

Injectable diacetylmorphine was more effective than oral methadone. Because of a risk of overdoses and seizures, diacetylmorphine maintenance therapy should be delivered in settings where prompt medical intervention is available. (ClinicalTrials.gov number, NCT00175357.)

Prescription of heroin for the management of heroin dependence: current status

The prescription of heroin (diamorphine) for the management of heroin dependence is a controversial treatment approach that was limited to Britain until the 1990s. Since then a number of countries have embarked upon clinical trials of this approach, and it is currently licensed and available in several European countries. To date, six randomized controlled trials (RCTs) with over 1600 patients and several cohort studies have examined injected (or inhaled) heroin treatment. This article reviews relevant clinical pharmacology, how heroin treatment programmes are delivered, and the evidence regarding safety, efficacy and cost-effectiveness from RCTs. Heroin is usually prescribed in intravenous dosages of 300-500 mg/day, divided in two or three doses. Uncommon but serious side effects include seizures and respiratory depression immediately following injection. Despite methodological shortcomings, RCTs generally indicate that heroin treatment results in a comparable retention, improved general health and psychosocial functioning, and less self-reported illicit heroin use than oral methadone treatment. Cost-effectiveness studies indicate heroin treatment to be more expensive to deliver but to result in savings in the criminal justice sector. There has been debate regarding how heroin treatment should be positioned within the range of treatment approaches for this condition. There is increasing consensus that, in countries that have robust and accessible treatment systems for heroin users, heroin treatment is suited to a minority of heroin users as a second-line treatment for those individuals who do not respond to methadone or buprenorphine treatment delivered under optimal conditions.

Scientific and political challenges in North America's first randomized controlled trial of heroin-assisted treatment for severe heroin addiction: rationale and design of the NAOMI study

BACKGROUND

Heroin addiction is a chronic relapsing disease, best treated with opioid-agonist substitution therapy such as methadone maintenance. However, a subset of the most severely affected individuals do not benefit sufficiently from this treatment. The North American Opiate Medication Initiative (NAOMI) is a randomized clinical trial (RCT) to evaluate the hypothesis that pharmaceutical-grade heroin, diacetylmorphine (DAM) is more effective in retaining patients and improving their outcomes than Methadone Maintenance Treatment (MMT) among those with chronic, refractory injection opioid dependence.

PURPOSE/METHODS

The study aimed at randomizing 253 participants to two intervention arms: (1) MMT alone or (2) injectable opioids (DAM or hydromorphone) plus adjunctive MMT if deemed appropriate. The planned study duration was 3 years, with a 1-year intake period, 1 year of treatment, and an additional year of follow-up. The NAOMI trial was initiated in March 2005 at two Canadian sites (Vancouver and Montreal). This was the first multicenter RCT in North America to compare the relative efficacy of these different therapeutic strategies. We discuss the rationale behind the NAOMI study design, as well as the scientific and political issues and methodological challenges arising from the conduct of a trial that involves the prescription of a controlled substance to individuals with dependence on that substance.

LIMITATIONS

Restrictive entry criteria led to the exclusion of many otherwise eligible participants, slowing recruitment into the study. Inability to offer DAM treatment beyond 12 months led to artificial boundary effects in the trial.

CONCLUSIONS

Addiction treatment research navigates between science and politics, and evidence-based medicine is many times confronted by moral beliefs. Political considerations influence study design to a further degree than in RCTs treating less-stigmatized disorders with more-reputable medications.