Early unwanted effects of fluphenazine esters related to plasma fluphenazine concentrations in schizophrenic patients.

Seven outpatients already receiving neuroleptic drugs by depot intramuscular injections were treated in two consecutive 3-week periods with 25 mg fluphenazine doses as enanthate and decanoate esters in a double-blind crossover study. They were assessed for incidence of akinesia, involuntary movement, autonomic disturbances and drowsiness, using a rating scale, and their blood pressures and pulse rates were recorded. Blood was collected for plasma fluphenazine and plasma prolactin assay. Additionally, a handwriting test was applied. A higher incidence of unwanted drug effects occurred when plasma fluphenazine concentrations were maximal, but this was not so with prolactin concentrations. No significant blood pressure changes occurred. Small increases in pulse rate and decreases in handwriting length occurred, but these changes were not associated with high fluphenazine levels.