Therapeutic potential of NMDA receptor antagonists in the treatment of alcohol and substance use disorders

Despite the fact that the use of alcohol, nicotine and other drugs is the major external factor contributing to mortality in industrialised countries, there are few medications available to treat alcohol and substance use disorders. In recent years, major advances have been made in the understanding of the neurobiological basis for these disorders and these advances should lead to the development of new pharmacotherapeutics. A substantial amount of the research suggests that N-methyl-D-aspartate (NMDA) receptor neurotransmission contributes to mediating the behavioural effects of alcohol and other drugs of abuse. This research supports the therapeutic potential of NMDA receptor antagonists in alcohol and substance use disorders. In this paper the authors present their opinion on the goals and stages of pharmacological treatment of these complex psychiatric disorders. Available preclinical research using designs that model aspects of alcohol and substance use disorders is summarised, with an emphasis on research published in the last two years. In animal models, NMDA antagonists inhibit physical dependence and the reinforcing effects of a variety of abused substances. The ability of NMDA antagonists to inhibit tolerance to drug effects and contribute possible antidepressant and anxiolytic effects are also important from the perspective of drug development. This review summarises the relevant clinical laboratory and treatment data. Finally, it presents the status of the current development of NMDA receptor antagonists and discusses candidates with the greatest potential for clinical development.