Plasma concentration of remoxipride in relation to antipsychotic effect and adverse symptoms. The Canadian Remoxipride Study Group.

The possible relationship between plasma concentration of remoxipride and antipsychotic effect/adverse symptoms has been evaluated in a 6-week double-blind dose-finding study in schizophrenic patients. The study comprised 3 parallel groups with fixed daily doses of 30-90 mg, 120-240 mg or 300-600 mg, divided in order to be given three times a day. A total of 79 patients from the three groups, who were treated with the maximum dose for 4 weeks or more, were included in the analysis. All patients had reached steady-state at week 2 and the intra-individual trough remoxipride plasma levels remained stable over the study period. The mean steady-state trough concentrations were found to be linearly related to the dose. Responders to remoxipride treatment were observed over the total concentration range of 0.24-13.50 mumols/l. Reductions of dose or discontinuations of treatment due to adverse symptoms were not associated with elevated remoxipride concentrations. In conclusion, no obvious relationship between plasma concentration of remoxipride and its antipsychotic effect or adverse symptoms was established.