Self-poisoning with baclofen in alcohol-dependent patients: national reports to French Poison Control Centers, 2008-2013

Background: Alcohol use disorders are frequently associated with self-intoxication in attempted suicide. In France since 2008, the off-label use of baclofen for treatment of alcohol dependence has greatly increased, leading to temporary regulation of use of the drug. At the request of the national authorities, the French Poison Control Centers carried out a retrospective survey to give an overview of baclofen exposure in this population. Methods: A retrospective study was carried out from January 2008 to December 2013, focusing on baclofen exposures in alcohol-dependent patients managed by the nine national French Poison Control Centers. Results: 294 observations of baclofen exposures in alcohol-dependent patients were identified in our database. Of these, 220 were suicide attempts by self-poisoning and 74 were unintentional. The mean age of patients was 41.7 years, with a sex-ratio of 1.6. Patients attempting suicide with baclofen were younger than those with unintentional exposures, and 43.6% of them were women (vs 22.9%, p< 0.01). The mean supposed ingested dose was higher (480.7mg) in patients who attempted suicide (vs 192.5 mg, p< 0.0001). 21.8% of intentional exposures involved baclofen alone. Psychiatric comorbidity (50.4%) was more frequent in the group of self- poisoning (p< 0.001). 132 patients were coded as severely exposed (60.0%). Nine victims died, but the causal link between self-poisoning with baclofen and fatal outcome should be interpreted with particular caution. Conclusions: Baclofen self-poisoning by alcohol-dependent patients is a serious concern for the French health authorities. Our results are similar to those previously published, suggesting that most patients with baclofen overdose should be admitted to an intermediate or intensive care unit as the clinical course requires close monitoring. Because suicidal ideation and suicide attempts are more prevalent in people with substance use disorders than in the general population, and because of the lack of recommendations governing baclofen prescription in such a situation, its use needs to be better controlled.