Baclofen as treatment for relapse in GHB abuse

GHB dependence is a growing health problem in the Netherlands. Attempts to stop using GHB are often followed by relapse in GHB use after successful detoxification. Observations show that craving and loss of control symptoms, associated with GHB dependence, contribute to quick and frequent relapse (two third of the patients within three months after detoxification).

To date management of GHB dependence after detoxification consists mostly of psychosocial treatment without pharmaco-therapeutic support. However, craving for and loss of control over GHB use might also be relieved by pharmaco-therapeutic treatment, as is the case in for example alcohol and heroin dependence. GHB is a GABA-B receptor agonist. The addictive properties of GHB are thought to be mediated by dopamine release in the mesolimbic dopamine circuitry, as is the case in other addictive substances. Baclofen also acts as a GABA-B receptor agonist and due to its specific receptor binding properties, it inhibits dopamine release in the mesolimbic circuitry. This is thought to contribute to its anti-craving properties and beneficial effects on relapse, as observed in alcohol dependent patients. As such, baclofen might be particularly suitable in the treatment of GHB dependence. Indeed, animal data have shown beneficial effects of baclofen on GHB self-administration in mice and there is some anecdotal evidence for beneficial effects on GHB withdrawal in humans.

The aim of the current study is to assess the potential of baclofen as an anti-craving agent in GHB dependent patients. We hypothesize that administration of baclofen to GHB dependent patients after detoxification is associated with reduced levels of craving for and less frequent relapse in GHB use, as compared to treatment as usual (without baclofen), without the occurrence of serious adverse effects.

The primary hypothesis is that treatment with baclofen will decrease the risk of relapse in GHB use and increase the duration of abstinence after detoxification in recently detoxified GHB dependent patients

Secondary hypotheses include:

1.treatment with baclofen will contribute to reduced levels of craving for GHB in recently detoxified GHB dependent patients.

2.the use of baclofen at therapeutic levels by recently detoxified GHB dependent patients is well tolerated without major side effects.

3.treatment with baclofen will contribute to recovery form psychiatric co-morbidity in recently detoxified GHB dependent patients.

Baseline

12 weeks

6 months

Patients will receive either baclofen as medication plus TAU or TAU alone. Baclofen will be uploaded over a 2 week period to a maximum of 45-60 mg. Baclofen will be administrated 3 times daily for 12 weeks.