ORAL ADMINISTRATION OF FLUPHENAZINE IN HEALTHY SUBJECTS: INTERACTION WITH COFFEE OR TEA
Date
1981
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
Type
Degree Level
Masters
Abstract
Fluphenazine is a piperazine phenothiazine derivative. It is used to alleviate psychoses of various etiologies but is particularly useful in the treatment of acute schizophrenia. It is also effective orally as the hydrochloride and as a depot intramuscular injection of its decanoate or enanthate ester in maintaining remission of schizophrenic symptoms. The doses of fluphenazine necessary to control psychotic episodes or to prevent relapse are highly variable. Concentrations of fluphenazine achieved in plasma are extremely low, in the nanogram per milliliter re-gion.
Recently a simple and specific radioimmunoassay procedure has been described which is also sufficiently sensitive to determine fluphenazine concentrations in plasma (Midha et ca., 1980). Unlike chlorpromazine, no data has as yet established "therapeutic plasma levels" of fluphenazine, but extreme intersubject variability has been noted in plasma concentra-tions (Wiles and Gelder, 1979; Sakalis et al., 1978).
An in vitro interaction of fluphenazine was reported with tea and coffee (Kulkanek et al., 1979). Precipitation of the drug occurred when a commercial fluphenazine preparation was mixed with each beverage. The sediment was not dissolved with hydrochloric acid or sodium hydroxide solutions. Such an interaction occurring in vivo could reduce the bioa-vailability of fluphenazine and alter its concentration in plasma. The latter might affect the clinical outcome of fluphenazine therapy in psy-chotic patients.
To verify the interaction of fluphenazine with tea and coffee, an in vitro study was performed with a commercially available liquid formula-tion. Precipitation occurred when coffee or tea was mixed with the flu-phenazine solution. Similar interaction was noted in vitro with chlor-promazine, haloperidol and perphenazine solutions.
To clarify the significance of any interaction occurring in humans between fluphenazine and tea or coffee, a clinical study was conducted in 12 healthy subjects ranging in age from 22 to 29 years. Each subject in-gested fluphenazine with water, coffee and tea in a randomized crossover design. Seven volunteers received tablets, the others received an oral liquid. Each dose was separated by a three-week washout period. Concen-trations of fluphenazine were determined by radioimmunoassay of plasma samples collected from each volunteer over a 32-hour period following each dose.
Description
Keywords
Fluphenazine
Citation
Degree
Master of Science (M.Sc.)
Department
Pharmacy