Serum neuroleptic levels during reduced dose fluphenazine decanoate maintenance therapy.
Forty-one remitted and chronically psychotic schizophrenic out-patients completed a two-year clinical trial during which they were assigned, on the basis of their clinically determined maintenance dosages, to one of two reduced, fixed-dose fluphenazine decanoate (FD) regimens: 35 mg/4 wks (19 patients) or 10 mg/4 wks (22 patients). Eighty-one percent of chronically psychotic patients, who represented 74% of the high dose group, relapsed, in comparison with only 38% of remitted patients (p < .001), who represented 86% of the low dose group. During this study serum neuroleptic levels were assessed, using the radioreceptor assay, before the administration of each FD injection and whenever a patient relapsed. Overall, 334 serum neuroleptic activity measurements were performed. Serum neuroleptic levels were detectable in all patients and were higher, although not significantly, in the 35 mg/4 wks group. The dichotomous clinical outcome of chronically psychotic and remitted patients occurred within the framework of essentially similar serum neuroleptic levels. These findings suggest that: 1) serum neuroleptic levels can be monitored during low dose FD treatment, 2) the poor maintenance therapy outcome of chronically psychotic patients cannot be accounted for by inadequate neuroleptic bioavailability, 3) a majority of remitted FD maintained patients retain their clinical response at serum neuroleptic levels lower than those initially attained at steady state.
Heresco-Levy
U
U
Ezrath Nashim-Herzog Memorial Hospital, Jerusalem, Israel.
Greenberg
D
D
Lerer
B
B
Javitt
D C
DC
Brown
W A
WA
D000328:Adult; D002908:Chronic Disease; D003692:Delayed-Action Preparations; D004305:Dose-Response Relationship, Drug; D005260:Female; D005476:Fluphenazine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D006801:Humans; D008134:Long-Term Care; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012559:Schizophrenia / Q000097:blood / Q000188:drug therapy*; D016896:Treatment Outcome
D003692:Delayed-Action Preparations; C011825:fluphenazine depot; D005476:Fluphenazine