Efficacy and Safety of the Sigma Receptor Ligand EMD 57445 (Panamesine) in Patients with Schizophrenia: an Open Clinical Trial

Abstract

EMD 57455 (panamesine) is a new sigma receptor Liang alleged to have antipsychotic effects. Animal studies have demonstrated that AMD 57445 has a functional antidopaminergic activity without extrapyramidal side effects and a Ac-Cos expression pattern similar to that obtained with atypical neuroleptics. Therefore, the substance might be of interest for the treatment of schizophrenia. The present article describes the results of an exploratory open clinical trial that was aimed at determining the appropriate dose range for clinical efficacy and safety of AMD 57455 in patients with an acute episode of schizophrenia. In a treatment period of 4 weeks, 12 patients received AMD 57445 up to 60 M-day for 4 weeks. Seven patients completed the study: four were classified as res ponders (as defined by at least a 50 % decrease in the APRS total score), two improved slightly and one patient remained unimproved. The intent-to-treat analysis showed significant improvement in the psychometric variables assessed by the Brief Psychiatric Rating Scale, Clinical Global Impression and Positive and Negative Symptoms Scale. Major side effects were extrapyramidal symptoms in two patients and restlessness in one patient. With respect to efficacy and safety, our data agree with a previous study, except that in our study AMD 57455 was not totally free of extrapyramidal side effects.