Perphenazine decanoate andcis(z)-flupentixol decanoate in maintenance treatment of schizophrenic outpatients

Abstract

Two groups of schizophrenic outpatients were treated with perphenazine decanoate (N = 20) and cis(z)-flupentixol decanoate (N = 24) respectively. Every 3 months the dose was gradually reduced until symptoms appeared that were suggestive of a prodromal phase of a psychotic episode. A slightly higher dose was then promptly reinstituted (the minimum effective dose). At each dose level, two blood samples were drawn for determination of serum concentration. The mean minimum effective dose of perphenazine decanoate was 99.3 mg/2 weeks (range 21.6-270.5), while the mean minimum effective dose of cis(z)-flupentixol decanoate was 60 mg/2 weeks (range 20-250). The corresponding mean serum level of perphenazine decanoate was 7.3 nmol/l (range 2.0-18.1) and of cis(z)-flupentixol decanoate 7.8 nmol/l (range 1.2-37.0). There was a significant correlation between the administered doses and the corresponding serum levels for both drugs (r = 0.87, P less than 0.01). A weak positive correlation was found between serum levels at the minimum effective dose and symptom intensity (BPRS total score) (r = 0.53, P less than 0.02) for perphenazine, but not cis(z)-flupentixol. No correlation was found between serum levels and side effects or length of neuroleptic treatment. It is concluded that the serum drug concentrations corresponding to the lowest effective dose are so variable that routine serum level monitoring may be of limited value in the long-term maintenance treatment of schizophrenia.

Psychopharmacology and adverse effects of antipsychotic long-acting injections: A review

“…Reported prevalences of such symptoms or use of anticholinergic drugs range from 29% 36 to 55%. 13 Other studies suggest high rates of extrapyramidal symptoms and hyperprolactinaemia with perphenazine enanthate, 67,68 but this ester of perphenazine is known to result in much higher plasma levels of perphenazine than perphenazine decanoate. 69 The total number of patients examined in well-conducted trials with either ester appears to be only 313.…”

Estimating the optimal dose of flupentixol decanoate in the maintenance treatment of schizophrenia—a systematic review of the literature

“…One study (Kistrup et al 1991) was specifically designed to establish the lowest effective dose for flupentixol decanoate in patients with schizophrenia. Patients stabilised on flupentixol decanoate had their dose systematically reduced by one quarter every 12 weeks until symptoms emerged.…”

A review of a recently published guidelines' “strong recommendation” for therapeutic drug monitoring of olanzapine, haloperidol, perphenazine, and fluphenazine

“…Every 3 months, the dose of the patients' PER LAI (not available in the United States) was reduced until symptoms appeared that were suggestive of a prodromal phase of a psychotic episode. The mean minimum effective plasma concentration was determined to be 2.92 ng/mL (range: 0.8 to 7.24 ng/mL); the authors29 found there was no correlation between serum concentrations and side effects and that levels were so varied that TDM may not be useful as employed in this study.…”

“…A minimum effective dose–finding study29 was conducted in 20 patients with schizophrenia who ranged in age from 18 to 65. Every 3 months, the dose of the patients' PER LAI (not available in the United States) was reduced until symptoms appeared that were suggestive of a prodromal phase of a psychotic episode.…”