Spectrofluorometric determination of olanzapine and fluphenazine hydrochloride in pharmaceutical preparations and human plasma using eosin: application to stability studies.

A simple, rapid, and sensitive spectrofluorometric method has been developed for the determination of olanzapine (OLZ) and fluphenazine hydrochloride (FPZ HCI). The proposed method is based on the quantitative quenching effect of the studied drugs on the native fluorescence of eosin at pH 3.4 and 3.2 for OLZ and FPZ HCI, respectively. The fluorescence was measured at 547 nm after excitation at 323 nm. The fluorescence-concentration plots were rectilinear over the range of 0.05-1.0 and 0.10-1.0 microg/mL, with lower detection limits of 1.8 x 10(-3) and 1.2 x 10(-3) microg/mL, for OLZ and FPZ HCI, respectively. The proposed method was successfully applied to the analysis of commercial tablets and ampules containing the drugs, and the results were in good agreement with those obtained with reference methods. The proposed method was further applied to the determination of OLZ in spiked human plasma. The mean recovery was 98.62 +/- 0.24% (n = 4). The method was also used for stability studies of FPZ HCI upon oxidation with hydrogen peroxide, and the kinetics of the reaction were studied. A proposal for the reaction pathway was postulated.

Quantitation of Haloperidol, Fluphenazine, Perphenazine, and Thiothixene in Serum or Plasma Using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS).

Haloperidol, fluphenazine, perphenazine, and thiothixene are "typical" antipsychotic drugs that are used in the treatment of schizophrenia and other psychiatric disorders. The monitoring of the use of these drugs has applications in therapeutic drug monitoring and overdose situations. LC-MS/MS is used to analyze plasma/serum extracts with deuterated analog of imipramine as the internal standard to ensure accurate quantitation and control for any potential matrix effects. Positive ion electrospray is used to introduce the analytes into the mass spectrometer. Selected reaction monitoring of two product ions for each analyte allows for the calculation of ion ratios which ensures correct identification of each analyte, while a matrix-matched calibration curve is used for quantitation.

Low serum neuroleptic levels predict relapse in schizophrenic patients.

Relapse occurs in a substantial proportion of schizophrenic patients treated with neuroleptics. The determinants of relapse have been elusive. In our study, low serum neuroleptic levels identified patients who had a relapse during a six-month period. Neuroleptic levels were measured by radioreceptor assay in 61 schizophrenic men and their clinical status was assessed in the subsequent six months. Ten patients had relapses, four showing a worsening of chronic psychotic symptoms and six showing eruption of psychotic symptoms after a period of remission. These ten patients had significantly lower normalized neuroleptic levels than those whose conditions remained stable. The lowest neuroleptic levels occurred in patients who had relapses after a period of remission. Serum neuroleptic levels in drug-responsive patients appear to be a critical determinant of remission. If these observations are replicated, a rational basis may be provided for prescribing and monitoring neuroleptic treatment and perhaps for preventing relapse.

Fluphenazine blood levels and clinical response.

The radioreceptor assay for neuroleptics (NRRA) holds out great theoretical promise as a method for monitoring blood neuroleptic levels, but its practical value is yet to be established. In the present study, 12 psychotic patients were followed longitudinally during treatment with oral (n = 9) and/or depot (N = 7) fluphenazine. Neuroleptic blood levels were determined both by the NRRA and by high performance liquid chromatography utilizing an electrochemical detector (HPLC). Clinical status was monitored by the Brief Psychiatric Rating Scale. Although blood levels were near the limits of sensitivity, the NRRA was able to detect the drug in most samples. HPLC was able to detect fluphenazine in less than 20% of the samples. Detectable blood levels by HPLC were associated with high blood levels by the NRRA. There was a significant correlation between blood levels as measured by the NRRA and clinical improvement. This correlation appears to be independent of the dose or route of administration of fluphenazine. Many patients were followed for several months and a few for over a year. A remarkable constancy of blood levels was found, particularly with depot administration. Given these findings, the NRRA may be an important clinical tool for monitoring patients receiving fluphenazine.

Tardive dyskinesia and serum iron indices.

BACKGROUND: This study was undertaken to evaluate whether peripheral (serum) markers of iron status are associated with severity of the choreoathetoid movements seen in tardive dyskinesia (TD). METHODS: Serum iron indices (ferritin, iron, and total iron binding capacity) and fluphenazine levels were measured in a group of 30 male DSM-III diagnosed schizophrenic patients chronically treated with fluphenazine decanoate. The severity of choreoathetoid movements was assessed with the Abnormal Involuntary Movement Scale (AIMS), and akathisia was assessed with the Barnes scale. RESULTS: A significant positive correlation was observed between AIMS scores and serum ferritin. This relationship remained significant after controlling for age and plasma fluphenazine levels. No significant correlations were observed between serum iron or total iron binding capacity and choreoathetoid movement ratings. There were no significant associations between serum iron indices and akathisia ratings. CONCLUSIONS: The data suggest that choreoathetoid movements are associated with serum ferritin levels in chronically medicated male schizophrenic patients. This relationship does not seem to be caused by an association of these variable with age or plasma fluphenazine levels. In addition, the relationship seems to be specific, since other iron indices and another extrapyramidal side effect (akathisia) do not demonstrate a similar relationship. In view of reports that antipsychotic medications change normal iron metabolism and increase iron uptake into the brain, the current results could be interpreted to suggest that serum ferritin levels may be a risk factor for TD in patients treated with "classic" antipsychotic medications.

Effects of dopamine agonists on Cebus apella monkeys with previous long-term exposure to fluphenazine.

Sixty-one weeks after 48 weeks of treatment with fluphenazine decanoate or placebo, 37 socially living Cebus apella monkeys were evaluated for differences in dopaminergic sensitivity by exposure to 0.75 mg/kg, i.m. of amphetamine (AMPH) (indirect agonist) and apomorphine (APOM) (direct agonist). The fluphenazine-treated animals differed (p < or = 0.05) from control animals on some hourly measures of composite behavioral variables (CBVs). Animals exposed to fluphenazine showed a greater decrease in the aggressiveness CBV and a smaller decrease in self- and environment-directed behaviors than placebo animals. CBVs for normal locomotion and directs affiliation showed no significant differences. The fluphenazine-treated group showed greater agonist induction of stereotypic behavior (p < or = 0.01), and larger decreases in prolactin response to AMPH (p < or = 0.05). Our findings indicate that following extended treatment with an antipsychotic there is increased sensitivity to dopamine, as evidenced by stereotypies and possibly hypophyseal responsiveness.

Relation of plasma fluphenazine levels to treatment response and extrapyramidal side effects in first-episode schizophrenic patients.

OBJECTIVE: The aim of this study was to determine the relation between plasma fluphenazine levels and clinical response in first-episode schizophrenic patients. METHOD: Data from 36 first-episode schizophrenic or schizoaffective inpatients diagnosed according to the Research Diagnostic Criteria were evaluated. The patients received open, standardized treatment with fluphenazine, 20 mg/day, for at least 4 weeks. Psychopathology was assessed biweekly, and plasma fluphenazine levels were ascertained weekly. Patients were classified as responders or nonresponders, and correlations between their neuroleptic levels and ratings of psychopathologic and extrapyramidal symptoms were computed. RESULTS: Plasma fluphenazine levels for weeks 1 through 4 were significantly correlated with each other but were not correlated with age, gender, diagnosis, or race. Mean neuroleptic levels (weeks 3 and 4) were not different between responders and nonresponders and were not correlated with measures of psychopathology or extrapyramidal symptoms. CONCLUSIONS: These results do not indicate an association between plasma fluphenazine levels and response to treatment or extrapyramidal side effects in first-episode schizophrenia. The disparity between the results of this study and those of previous studies may be due to methodological differences or to a biologically based difference between first-episode and chronic patients.

Fluphenazine plasma levels, dosage, efficacy, and side effects.

OBJECTIVE: The authors sought to determine whether fluphenazine dose or plasma level predicts clinical improvement or side effects during acute treatment. METHOD: Oral fluphenazine was given in fixed, randomized, double-blind doses (10, 20, or 30 mg/day) for 4 weeks to 72 inpatients with acute schizophrenic exacerbations. Outcome measures included percentage improvement in ratings of positive symptoms (hallucinations, delusions, and thought disorder), percentage improvement in negative symptoms, and maximum score for extrapyramidal symptoms. Response was defined as an improvement in positive symptoms of 40% or more. RESULTS: The 42 responders had a shorter duration of illness, less chronic course, and lower rate of akathisia. Plasma level and dose did not differentiate responders and nonresponders, but they did predict percentage improvement in positive symptoms within the responder subgroup. Akathisia was more common and extrapyramidal symptoms were more severe at higher plasma levels. CONCLUSIONS: Responders showed the greatest improvement at fluphenazine plasma levels above 1.0 ng/ml and doses above 0.20-0.25 mg/kg per day. Since the literature suggests that optimal plasma levels are similar during acute and maintenance treatment, monitoring of plasma levels may thus be useful. Conditions for applying the "responder-only" analytic strategy in future studies are discussed.

Neuroleptic augmentation with alprazolam: clinical effects and pharmacokinetic correlates.

Alprazolam added to stable doses of neuroleptics in nine schizophrenic patients was associated with a 20%-30% mean reduction in positive and negative symptoms, although clinical response was variable and in some patients particularly brisk. The authors examined the possibilities of a pharmacokinetic effect of alprazolam on neuroleptic plasma levels and of a clinical effect of alprazolam. The modest increase in mean neuroleptic plasma levels did not correlate with clinical change, but those patients with the highest alprazolam plasma levels tended to show more robust clinical responses.

Low neuroleptic serum levels in patients receiving fluphenazine decanoate.

The authors monitored serum levels of fluphenazine in nine patients following injections of fluphenazine decanoate ranging from 10 to 75 mg. Levels were detected by a radioreceptor assay based on the ability of the drug to complete with 3H-spiroperidol for binding to dopamine receptors in rat caudate membranes. Serum levels of fluphenazine were quite stable over a 2- to 3-week period following single intramuscular injections of the decanoate and correlated with injected dose. Following decanoate treatment serum levels of fluphenazine are substantially lower than levels observed for most other neuroleptics administered orally. This raises questions as to how fluphenazine decanoate can exert therapeutic actions.

Measurement of blood levels of neuroleptics and metabolites by combined high performance liquid chromatography-radioreceptor assay for D2 and sigma sites.

The dopamine (D2) receptor blocking property of antipsychotic medications has been proposed as the mechanism of the therapeutic activity of this class of drugs. This property has also been exploited as a method to quantify therapeutic levels of these drugs in patients. However, the lack of correlation among dosage, blood levels and clinical response has resulted in a contradictory literature on both mechanism and quantification of these drugs. Bioactivity and chemical identity of the commonly prescribed neuroleptic drug fluphenazine and its metabolites in human plasma were determined by a new method which combines the selectivity of chemical methods with the sensitivity and bioassay of the radioreceptor assay (RRA) method. Fluphenazine and its metabolites were separated and identified in human plasma by an ion-pairing reverse phase high performance liquid chromatographic method with electrochemical detection. A volatile buffer system was employed which was compatible with facile sample preparation for post-column analyses, and which provided sharp, symmetrical chromatographic peaks of parent compound and metabolites. Post chromatography, HPLC fractions were assayed by RRA for D2, alpha 1 and sigma receptors. More than one pattern of metabolism of the drug was seen, including biosynthesis of drug metabolites with biological activities at these receptor types. The individual differences with which this occurs may contribute to the variabilities seen in clinical response to neuroleptics, and to difficulties in neuroleptic blood level determinations.

Fluphenazine plasma levels and clinical response.

Plasma levels of fluphenazine and clinical response were examined in 19 inpatient schizophrenics (DSM-III diagnoses) using a constant dose, steady-state methodology. A significant curvilinear correlation was demonstrated between clinical response and steady-state plasma levels of fluphenazine (p less than .05). A therapeutic range of plasma fluphenazine is suggested in the range of .13-.70 ng/ml. The lowest plasma level detected (.13 ng/ml) appeared to be well within the therapeutic range. The 9 patients with plasma fluphenazine levels in this range demonstrated a mean clinical improvement of 59% compared to 34% for patients with plasma levels above .70 ng/ml (p less than .01).

Clinical effectiveness of oral and parenteral rapid neuroleptization.

A random assignment, double-blind, placebo-controlled evaluation was used to compare the effectiveness of rapid parenteral injections of fluphenazine hydrochloride with that of oral doses of the same drug in 16 patients with acute psychotic illnesses. Doses of fluphenazine hydrochloride were much higher in the parenteral neuroleptization group than in the oral administration group during the acute phase, although oral doses were equivalent during the continuation phase. The rate of improvement was not different for the two groups, but the rate of extrapyramidal side effects was higher in the parenteral neuroleptization group. The results suggest that rapid parenteral neuroleptization for the acute treatment of psychosis offers more risks than benefits.

Relapse in chronic schizophrenics treated with fluphenazine decanoate is associated with low serum neuroleptic levels.

Seventy-three chronic schizophrenic outpatients were studied for 1 year to determine if neuroleptic drug levels could be useful in preventing relapse. All patients received fluphenazine decanoate i.m., and serum level of neuroleptic was determined by radioreceptorassay. Clinical improvement was measured using the Global Assessment Scale. Results indicate that serum neuroleptic drug levels may be useful in the outpatient management of chronic schizophrenics.

Low-dose treatment strategies.

Dose-comparison studies in chronic, continuously hospitalized patients show that megadoses of antipsychotic drugs are reasonably well tolerated. These findings, together with dose-comparison studies in acute patients, support the notion (and current practice) that the therapeutic index of antipsychotic drugs is wide. Recent work with outpatients indicates that fluphenazine decanoate 5 mg (versus 25 mg) every 2 weeks is effective for at least the first year. In addition, patients report feeling better when they take the lower dose. A dose-comparison study with haloperidol in newly admitted patients indicates that a 20 mg daily dose has neurotoxic effects. A similar dose-comparison study with oral fluphenazine indicates that a 5 mg daily dose is efficacious over a 3-week period. Thus, both inpatients and outpatients can be managed on doses that were formerly regarded as homeopathic. Patients taking low doses have fewer side effects (particularly less akinesia) and probably fewer dysphoric emotions than patients taking high doses, although they improve at a slower rate.

Bioavailability of psychotropic drugs: historical perspective and pharmacokinetic overview.

The evolution of the federal government's role in the regulation and evaluation of generic psychotropic medications is described. To place many of the methodologic bioequivalence issues for antipsychotic agents into perspective, the pharmacokinetics of these drugs are reviewed. Appropriate methodologies for studying the pharmacokinetics and pharmacodynamics of psychotropic drugs are in early developmental stages. Many of the issues relating to bioequivalence of generic products will not be resolved until a better understanding of these factors is developed.

Blood levels of neuroleptics: state of the art.

Difficulties in developing techniques to measure plasma levels of neuroleptic drugs have included the presence of metabolites, as well as cross-reactivity not only between these metabolites and the parent compound but between drugs (e.g., a phenothiazine and a tricyclic). Although newer techniques have minimized some of these problems, interpretation of published data must also recognize such design limitations as variable dose, small sample size, etc. The literature is reviewed on the relationship between therapeutic response and plasma levels of chlorpromazine, thioridazine, thiothixene, fluphenazine, butaperazine, and haloperidol. It is suggested that additional studies, carefully designed, on dosage and plasma levels could help in achieving the lowest possible therapeutic dosage and thus in minimizing side effects.

Fluphenazine activity and antipsychotic response.

Plasma fluphenazine levels and plasma total neuroleptic activity (as quantitated by the neuroleptic receptor binding assay) were related to therapeutic response in 15 DSM-III schizophrenic patients who received a predetermined, fixed dose of fluphenazine for 14 days. Mean neuroleptic activity of the plasma was 84% greater than can be accounted for by the parent fluphenazine alone, and varied widely between patients. A sigmoidal relationship between total neuroleptic activity of plasma and response was found, with a continued plateau of response at higher total neuroleptic levels. Furthermore, the RBA data suggested (P less than 0.002) that two populations of drug-responsive schizophrenics exist which may be discriminated by the total D2 binding activity of plasma required for response.

Fluphenazine plasma levels in patients receiving low and conventional doses of fluphenazine decanoate.

Plasma fluphenazine concentrations (FLU) were measured in 45 patients with schizophrenic disorders who participated in a double-blind comparison of 5 and 25 mg fluphenazine decanoate (FD). The rise in plasma level of FLU 24 h after a "test dose" was significantly correlated with steady state FLU concentration at 12 weeks (for 5 mg patients, r = 0.45, P = 0.04; for 25 mg, r = 0.78, P = 0.005). Patients who had low FLU at baseline required nearly 6 months to reach a steady state when they received 25 mg. Patients who received 5 mg and had low FLU at baseline continued to demonstrate relatively low plasma levels for the entire 1st year. Although the mean FLU at 6 months was lower for patients who relapsed during the subsequent 18 months (0.57 ng/ml for relapsers vs 1.01 ng/ml for nonrelapsers), this difference was not statistically significant. When plasma levels from both dosage groups were combined, FLU at 12 weeks correlated significantly with factor scores for akinesia (r = 0.52, P = 0.002) and BPRS cluster scores for retardation (r = 0.52, P = 0.002). These results indicate that the measurement of fluphenazine plasma levels may be useful in determining when patients treated with FD are receiving drug doses which are likely to cause discomforting side effects.

Fluphenazine pharmacokinetics and therapeutic response.

We conducted a double-blind study of therapeutic outcome versus mean steady-state levels in 29 newly admitted schizophrenic and schizoaffective patients who were treated with a constant dose of fluphenazine HCI over a 2-week period. both an upper and lower end of the therapeutic window were suggested by three nonresponders whose plasma levels were above 2.8 ng per ml and by two nonresponders and one partial responder whose plasma levels were below 0.2 ng per ml. The mean terminal half-life of fluphenazine (+ or - SD) was 16.4 + or - 13.3 h. We found that concomitant use of benztropn mesylate during the initial 4 weeks of fluphenazine treatment did not significantly alter fluphenazine plasma levels.