Results of the clinical study of efficacy and tolerability of mexidol administered in intravenous drop-by-drop introduction during 5-7 days in the therapy of 50 cases of complicated alcoholic delirium are presented. The patient condition and changes in device test data were assessed in comparison with those of a control group of patients receiving a basic therapy without mexidol. It is shown that mexidol has stopped psychosis in shortest terms thus decreasing secondary complications and lethality.