Pettinati 2008: disulfiram and naltrexone for cocaine plus alcohol

What they tested

Patients were randomly assigned to disulfiram 250 mg a day, naltrexone 100 mg a day, both drugs, or a placebo (a dummy pill) for 11 weeks. Neither patients nor staff knew who was taking what.

The outcomes were abstinence from cocaine and from alcohol during the trial, measured by urine tests for cocaine and by what patients reported.

What they found

In the main analyses, cocaine-free urine tests and self-reported days without cocaine or alcohol did not differ between placebo and any of the medicine groups.

Patients taking disulfiram, alone or with naltrexone, were the most likely to achieve abstinence from both cocaine and alcohol at once.

In secondary analyses, the disulfiram-naltrexone combination group was the most likely to reach 3 consecutive weeks without cocaine or alcohol.

There were few safety concerns, but many patients didn't take their medicine reliably, whether on one drug or both.

Limits

• Low adherence to the medicines makes it harder to tell whether the drugs would work if taken as prescribed.
• The combination's advantage came from secondary analyses, not the main ones the trial was designed to test.
• It included only people dependent on both cocaine and alcohol, and naltrexone was given at 100 mg a day, double the usual 50 mg tablet.

What it means if you're considering naltrexone

For people who use both cocaine and alcohol, this trial gives little support for naltrexone on its own: it didn't beat placebo on the main outcomes. Any benefit in the trial was tied to disulfiram, with the combination showing an edge only on a secondary measure.

It also showed that taking naltrexone together with disulfiram raised few safety concerns in this group.