Efficacy and safety of an opiate sigma-receptor antagonist (SL 82.0715) in schizophrenic patients with negative symptoms: an open dose-range study.

The psychotomimetic effects of opiate agonists/antagonists led to the hypothesis that opiate sigma receptors could be involved in the etiology of schizophrenia. This assumption is supported by animal trials with selective sigma-receptor antagonists. SL 82.0715 is a substance with a highly selective affinity for sigma receptors. To clarify the question whether it improves negative symptoms of schizophrenia, ten chronic schizophrenic patients with a predominant negative symptomatology were examined and treated with increasing doses (2.5 - 10.0 mg/d). Psychopathology was evaluated weekly using the PANSS, BPRS, and CGI, side-effects were assessed by the HAS and the S/A scale. Four patients showed improvement of negative symptoms (two slight, two marked improvement), two patients deteriorated as regards the positive symptomatology, psychopathology in the other patients did not change. The tolerability of SL 82.0715 was very good, no extrapyramidal side-effects occurred. To further evaluate the therapeutic efficacy, open studies with a larger number of patients and/or double-blind studies are necessary.