Le nalméfène représente une option nouvelle dans le traitement de l’alcoolodépendance. Cette molécule a reçu une AMM européenne en 2013 pour réduire la consommation d’alcool des patients adultes ayant une consommation à risque élevé selon la classification de l’OMS (i.e. plus de 60 g d'alcool par jour pour les hommes, ou plus de 40 g par jour pour les femmes). Toutefois, les avis dans la littérature divergent quant à son intérêt. Nous avons donc souhaité réévaluer le rapport bénéfice-risque de cette molécule en appliquant des méthodes appartenant au domaine de la méta-recherche. Une première méta-analyse des essais randomisés contrôlés comparant le nalméfène par voie orale à un placebo nous a permis de mettre en évidence des tailles d’effet faibles sur les critères de consommation, avec un possible biais d’attrition dans les études. Dans une seconde méta-analyse en réseau évaluant l’efficacité, dans l’indication de réduction des consommations, du nalméfène à d’autres traitements également utilisés dans la prise en charge de l’alcoolodépendance, nous avons conclu à l’absence de preuve de haut niveau de l’efficacité des traitements pharmacologiques pour contrôler la consommation d'alcool chez les patients non abstinents souffrant de troubles liés à l’usage. Enfin, nous avons montré, à travers la réalisation d’un grand nombre de méta analyses, que les choix méthodologiques faits dans les essais randomisés contrôlés évaluant le nalméfène et la naltrexone dans la prise en charge de l’addiction à l’alcool entraînaient une variation substantielle de l’estimation de l’efficacité de ces deux traitements, phénomène également appelé « vibration de l’effet » des traitements. / Nalmefene is a new option in the treatment of alcohol dependence. It was approved by the European Medicines Agency to help reduce alcohol consumption in adults who consume more than 60 g of alcohol per day (for men) or more than 40 g per day (for women). However, researchers’ opinions on the interest of the drug are divided. We therefore planned direct and network meta-analyses to enable an objective reappraisal of the efficacy of nalmefene. A first meta-analysis of randomized controlled trials comparing oral nalmefene with placebo showed small effect sizes on consumption criteria with a possible attrition bias in the studies. In a second network meta-analysis evaluating the comparative efficacy of nalmefene to control drinking with other treatments also used in the management of alcohol dependence, we concluded that there was no high-grade evidence for pharmacological treatment to control drinking in non-abstinent patients with alcohol use disorders. Finally, we explored the vibration of effects in a large number of overlapping indirect meta-analyses comparing nalmefene versus naltrexone to reduce alcohol consumption. We demonstrated that the methodological choices made in randomized controlled trials resulted in a substantial variation in the effect sizes of these two treatments.

Background: Alcohol consumption is one of the most important factors for disease and disability in Europe. In clinical trials, nalmefene has resulted in a significant reduction in the number of heavy-drinking days (HDDs) per month and total alcohol consumption (TAC) among alcohol-dependent patients versus placebo. Methods: A microsimulation model was developed to estimate alcohol-attributable diseases and injuries in patients with alcohol dependence and to explore the clinical relevance of reducing alcohol consumption. Results: For all diseases and injuries considered, the number of events (inpatient episodes) increased with the number of HDDs and TAC per year. The model predicted that a reduction of 20 HDDs per year would result in 941 fewer alcohol-attributable events per 100,000 patients, while a reduction in intake of 3,000 g/year of pure alcohol (ethanol) would result in 1,325 fewer events per 100,000 patients. Conclusion: The potential gains of reducing consumption in alcohol-dependent patients were considerable.

Reduction of long-term mortality risk, an important clinical outcome for people in alcohol dependence treatment, can rarely be established in randomized controlled trials (RCTs). We calculated the reduction in all-cause mortality risk using data from short-term (6 and 12 months) double-blind RCTs comparing as-needed nalmefene treatment to placebo, and mortality risks from meta-analyses on all-cause-mortality risk by reduction of drinking in people with alcohol dependence. A reduction in drinking in the RCTs was defined by shifts in drinking risk levels established by the European Medicines Agency. Results showed that the reduction of drinking in the nalmefene group was associated with a reduction in mortality risk by 8% (95% CI: 2%, 13%) when compared to the placebo group. Sensitivity analyses confirmed a significant effect. Thus comparing the difference between nalmefene and placebo in reduction in drinking levels with results on all-cause mortality risk from meta-analyses indicated a clinically relevant reduction in mortality risk. Given the high mortality risk of people with alcohol dependence, abstinence or a reduction in drinking have been shown to reduce mortality risk and should be considered treatment goals.