Dopamine D2 Receptor Occupancy Estimated From Plasma Concentrations of Four Different Antipsychotics and the Subjective Experience of Physical and Mental Well-Being in Schizophrenia: Results From the Randomized NeSSy Trial.

BACKGROUND: Impaired subjective well-being in schizophrenia patients treated with antipsychotics has often been linked inter alia to the antidopaminergic effects of medication. Thus, it is important to capture the association between striatal dopamine D2 receptor occupancy (D2-RO) and global subjective well-being. We examined this association using data from our multicenter, randomized, double-blind Neuroleptic Strategy Study (NeSSy). METHODS: An innovative double randomization process was used for allocation of patients to the specific treatment groups. Plasma drug concentrations were measured after 6 and 24 weeks of treatment to obtain the estimated D2-RO (eD2-RO) relative to literature values. We made an exploratory analysis of associations between eD2-RO and subjective well-being scores. One hundred two blood samples from 69 patients were available for the analysis. Because of the lack of a satisfactory occupancy model for quetiapine, only haloperidol, flupentixol, and olanzapine treatment groups were pooled, whereas aripiprazole data were analyzed separately, because of its partial agonistic properties. RESULTS: In the pooled antagonist group, eD2-RO correlated negatively with the summarized well-being score. In a more detailed analysis, this association could be confirmed for all first-generation antipsychotic-treated patients, but not for the separate second-generation antipsychotic groups. In the aripiprazole group, higher eD2-RO was associated with impaired physical well-being, but had no association with mental well-being. CONCLUSIONS: Our results suggest that high plasma levels and consequently high occupancy at D2 receptors are disadvantageous for subjective well-being, as distinct from the objective extrapyramidal side effects. To minimize patients' malaise, which disfavors adherence, implementation of therapeutic drug monitoring in the clinical routine may be useful.

Pharmaceutical and pharmacokinetic evaluation of a novel fast dissolving film formulation of flupentixol dihydrochloride.

The objective of the present study was to develop fast dissolving oral film of the antipsychotic drug, flupentixol dihydrochloride, to enhance its bioavailability, optimize its therapeutic effect when used to treat depression with anxiety, and increase the convenience and compliance by the mentally ill, developmentally disable, elderly, and pediatric patients. Six formulae were prepared with different concentrations of water-soluble polymers vis. hydroxypropyl methylcellulose (HPMC E5) and carboxymethyl cellulose (CMC) by solvent casting technique. The prepared films were subjected to characterization for folding endurance, weight variations, thickness, disintegration time, drug release pattern, and drug content. Physical compatibility between the drug and excipients was guaranteed in the selected formulation (2% HPMC) by means of differential scanning calorimetry analysis and Fourier-transform infrared spectroscopy. This formulation revealed high stability after testing according to the International Conference on Harmonisation guidelines. In vivo studies based on single phase parallel design were carried out for the optimized formulation in healthy human volunteers. The concentration of flupentixol dihydrochloride in plasma samples was analyzed by a developed validated LC-MS/MS assay method and the pharmacokinetic parameters of the established formulation were compared with the commercially available oral tablets. Faster rate of absorption of flupentixol could be obtained from the oral film formulation and the relative bioavailability was found to be 151.06% compared to the marketed product.

Validation of a sensitive LC/MS/MS method for simultaneous quantitation of flupentixol and melitracene in human plasma.

A sensitive method has been developed and validated, using LC/ESI-MS/MS, for simultaneous quantitation of flupentixol and melitracen--antidepressant drugs, in human plasma. The quantitation of the target compounds was determined in a positive ion mode and multiple reaction monitoring (MRM). The method involved a repeated liquid-liquid extraction with diethyl ether and analytes were chromatographed on a C(8) chromatographic column by elution with acetonitrile-water-formic acid (36:64:1, v/v/v) and analyzed by tandem mass spectrometry. The method was validated over the concentration ranges of 26.1-2090 pg/ml for flupentixol and 0.206-4120 ng/ml for melitracen. The correlation coefficients of both analyst were >0.998 for six sets of calibration curves. The recovery was 60.9-75.1% for flupentixol, melitracen and internal standard. The lower limit of quantitation (LLOQ) detection was 26.1 pg/ml for flupentixol and 0.206 ng/ml for melitracen. Intra- and inter-day precision of the assay at three concentrations were 2.15-5.92% with accuracy of 97.6-103.0% for flupentixol and 0.5-6.36% with accuracy of 98.7-101.7% for melitracen. Stability of compounds was established in a battery of stability studies, i.e., bench-top, autosampler and long-term storage stability as well as freeze/thaw cycles. The method proved to be suitable for bioequivalence study of flupentixol and melitracen in healthy human male volunteers.

A selective 19F nuclear magnetic resonance spectroscopic method for the assay of the neuroleptic drug cis(Z)-flupentixol in human serum.

This investigation was carried out to evaluate 19F nuclear magnetic resonance as an analytical tool for the measurement of the cis(Z) and trans(E) stereoisomers of the antipsychotic drug flupentixol in human serum. The method is based on the integration of appropriate signals of both analytes and an internal standard. The proposed method was applied to the analysis of real samples without any interference, manipulation of large samples, and lengthy instrument time. Experimental parameters were selected to optimize accuracy, precision, and analysis time. The calibration curves in human serum matrix were linear for cis(Z)- and trans(E)-flupentixol over the ranges 4.0-50.0 and 2.6-25.0 microg/mL, respectively, with respective minimum detectable limits (S/N=3) of 1.67 and 1.72 microg/mL. The method was validated through spike and recovery for the two isomers of flupentixol from a human serum matrix.

HPLC-ESI-MS/MS determination of zuclopenthixol in a fatal intoxication during psychiatric therapy.

The first non-suicidal fatality due to intramuscular administration of Cisordinol (zuclopenthixol, ZPT) is described. A new, rapid, and sensitive method for the determination of ZPT in postmortem specimens has been developed. High performance liquid chromatography electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) was employed for drug confirmation and quantitation. Sample clean up was performed using a simple liquid-liquid extraction procedure. The postmortem concentration of ZPT in heart blood was 0.68 microg/ml. Furthermore, zotepine, carbamazepine, and chlorprotixene were detected in body fluids. The proposed method enables the unambiguous identification and quantitation of ZPT and other neuroleptic drugs in clinical and forensic specimens.

Flow-injection chemiluminometric determination of some thioxanthene derivatives in pharmaceutical formulations and biological fluids using the [Ru(dipy)3(2+)]-Ce(IV) system.

A flow-injection (FI) methodology using tris(2,2'-dipyridyl)ruthenium(II), [Ru(dipy)3(2+)], chemiluminescence (CL) was developed for the rapid and sensitive determination of three thioxanthene derivatives, namely zuclopenthixol hydrochloride, flupentixol hydrochloride and thiothixene. The method is based on the CL reaction of the studied thioxanthenes with [Ru(dipy)3(2+)] and Ce(IV) in a sulfuric acid medium. Under the optimum conditions, calibration graphs were obtained over the concentration ranges 0.002-6 migrograms/ml for zuclopenthixol hydrochloride, 0.5-15 micrograms/ml for flupentixol hydrochloride and 0.05-7.5 micrograms/ml for thiothixene. The limits of detection (s/n = 3) were 4.2 x 10(-9) mol/l zuclopenthixol hydrochloride, 2 x 10(-8) mol/l flupentixol hydrochloride and 4.5 x 10(-8) mol/l thiothixene. The method was successfully applied to the determination of these compounds in dosage forms and biological fluids.

Quantification of the antipsychotics flupentixol and haloperidol in human serum by high-performance liquid chromatography with ultraviolet detection.

A high-performance liquid chromatography (HPLC) method was developed for quantification of both isomers of the thioxanthene neuroleptic flupentixol and of the butyrophenone derivative haloperidol in human serum. After extraction with diethyl ether-n-heptane (50:50, v/v), an isocratic normal-phase HPLC system with a Hypersil cyanopropyl silica column (250x4.6 mm, 5 microm particle size) was used with ultraviolet detection at 254 nm and elution with a mixture of 920 ml acetonitrile, 110 ml methanol, 30 ml 0.1 M ammonium acetate, and 50 microl triethylamine. The limit of quantitation of 0.5 ng/ml and 0.3 ng/ml for flupentixol and haloperidol, respectively, was sufficient to quantify both compounds in serum after administration of clinically adjusted doses. The suitability of the described method for therapeutic drug monitoring and clinical pharmacokinetic studies was assessed by analysis of more than 100 trough level serum samples.

A capillary gas-liquid chromatographic method for the assay of the neuroleptic drug zotepine in human serum or plasma.

A capillary gas-liquid chromatographic method suitable for the assay of the atypical neuroleptic drug zotepine in human serum or plasma was developed. A liquid-liquid extraction with three subsequent extraction steps was applied for sample preparation. The minimum detectable concentration was 1.0 ng ml-1. The within-day relative standard deviation (RSD) (n = 6) was 5.3% at 5 ng ml-1, 3.6% at 10 ng ml-1 and 6.1% at 100 ng ml-1. The day-to-day RSD (n = 6) was 9.3% at 10 ng ml-1 and 5.1% at 100 ng ml-1. Steady-state serum levels of four schizophrenic patients were measured.

Sensitive gas-liquid chromatographic method for the assay of the neuroleptic drug cis(Z)-flupentixol in human serum or plasma.

A gas-liquid chromatographic (GLC) assay suitable for the analysis of the cis(Z)-stereoisomer of the antipsychotic drug flupentixol in human serum or plasma was developed. The minimal quantifiable concentration was 0.5 ng/ml and the day-to-day coefficient of variation was 11.2% at 1 ng/ml and 8.7% at 10 ng/ml. Following addition of perphenazine as the internal standard (I.S.) and aqueous NaOH, samples (2 ml) are extracted with n-hexane-isoamyl alcohol (98.5:1.5, v/v) (solvent), back-extracted to 0.1 M HCl and after one washing-step and addition of aqueous NaOH again extracted into 100 microliters solvent. After evaporation to dryness, the extract is reconstituted in 20 microliters solvent and evaporated to approximative 10 microliters. A 4-microliter aliquot is injected cool on-column onto the GLC system. A gas chromatograph HP 5890 with on-column injection port, nitrogen-phosphorus detector (NPD), a HP-1 25 m x 0.32 mm I.D., 0.52 micron capillary and hydrogen (3 ml/min, automated pressure control) as the carrier gas was applied. The negative influence of light on the assay was measured and discussed. The suitability of this method for clinical pharmacokinetic studies and therapeutic drug monitoring (TDM) was determined by the analysis of serum samples of 12 schizophrenic patients.

Perphenazine decanoate and cis(z)-flupentixol decanoate in maintenance treatment of schizophrenic outpatients. Serum levels at the minimum effective dose.

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.

Cis-flupentixol metabolites in rat plasma and bile. The first proof of glutathione conjugation at the exocyclic double bond.

The plasma and biliary metabolites of cis-flupentixol (cis-FPT) were studied after ip administration to rats. Cis-FPT sulfoxide was found to be the major phase-I metabolite in plasma and bile. Five biliary metabolites were isolated by gradient elution HPLC and characterized by various spectroscopic methods: F1, 1'-S-glutathionyl-10,1'-dihydroFPT sulfoxide; F2, cis-FPT sulfoxide sulfate; F3, 8-O-(or 7-O) glucuronyl-cis-FPT; F4, cis-FPT sulfoxide; and F5, cis-FPT glucuronide. A novel non-enzymatic addition of glutathione (GSH) onto the exocyclic double bond was demonstrated to occur for the first time with not only flupentixol and certain of its metabolites, but also with other psychotropic drugs with a tricyclic nucleus and an exocyclic double bond. Specifically, these nonenzymatic additions of GSH were observed with cis-FPT, trans-FPT, cis-FPT sulfoxide, cis-, trans-dealkylFPT, cis-FPT N-oxide, cis-chlorprothixene, cis-thiothixene, and cyclobenzaprine. Among them, cis-FPT sulfoxide showed the most potent adduct formation activity, and the product was characterized to be identical with the in vivo metabolite F1 of cis-FPT.

Objective and subjective assessments of the effects of flupentixol and benzodiazepines on human psychomotor performance.

The aim of this double-blind crossover trial was to compare the objective and subjective effects of flupentixol and lorazepam on human performance, and to reveal possible interactions between flupentixol and diazepam. Twelve healthy students received at 1-week intervals oral single doses of flupentixol 1 mg, flupentixol 2 mg, lorazepam 2.5 mg, placebo, and diazepam 15 mg alone and with flupentixol 1 mg. After the baseline measurements, the drugs were given in capsule form, and the tests were repeated 1.5, 3 and 4.5 h later. Diazepam was given at 1.5 h, to time its peak effect to coincide with that of lorazepam. Drug effects were measured objectively (two tracking tests, digit substitution, letter cancellation, flicker fusion, Maddox wing, tapping, memory) and subjectively (visual analogue scales, questionnaire). Blood samples were taken after each test time. Flupentixol 1 mg did not differ from placebo objectively or subjectively. Flupentixol 2 mg proved nearly inert objectively and on visual analogue scales. Lorazepam impaired objectively measured test performance, the clearest effects occurring at 3 and 4.5 h. It also impaired subjectively assessed performance. Diazepam impaired objective performance less than lorazepam, its effects peaking at 1.5 h after intake. Diazepam caused subjective drowsiness, clumsiness, mental slowness etc. as much as or more than lorazepam. The combination of 1 mg flupentixol and diazepam modified performance as much as diazepam alone. After the administration of 1 mg flupentixol, plasma concentrations were undetectable and levels after 2 mg were hardly detectable. Concentrations of lorazepam exceeded those of diazepam in direct bioassay, but they were much lower when bioassayed after solvent extraction.(ABSTRACT TRUNCATED AT 250 WORDS)

Milk concentrations of flupenthixol, nortriptyline and zuclopenthixol and between-breast differences in two patients.

Flupenthixol (FP), nortriptyline (NT) and zuclopenthixol, (ZCP) were determined in breast milk and plasma from 2 puerperal, lactating women with psychiatric disorders. The milk concentrations were equal to, higher and lower than those in plasma for FP, NT and ZCP, respectively. Variation in milk triglyceride concentration, but not milk pH, could partly explain between-breast differences in the milk concentrations. The study demonstrates the need for appropriate and representative milk sampling procedures. The estimated daily infant exposure averaged 0.5, 2.3 and 0.3% of the corresponding maternal weight related doses of FP, NT and ZCP. FP was also detectable in infant plasma. These drugs are not known to be harmful in small doses to breast-fed infants. However, concern about the effect of dopamine blocking agents on neurobehavioral mechanisms in animals warrants caution. If neuroleptics are required for a long period this risk must be weighed against the benefits of breast-feeding, also considering the psychological effects of the latter.

Radioreceptor assay in checking serum concentration in long-term treatment with cis(z)-flupenthixol decanoate.

24 patients have been treated with cis(z)-flupenthixol decanoate for 6-12 months. Intramuscular injections were given about every 3 weeks. Before treatment and on each day of injection the mental state was assessed by BPRS and registration of side effects was performed. Blood samples were taken 7 days after each injection and on the last day of the dosage interval. Neuroleptic activity was determined in serum by RRA and expressed in cis(z)-flupenthixol equivalents. The drug level was significantly correlated to the dose. No clear relationship between drug level and clinical results as well as side effects was found. Less pronounced variations of the drug level between subsequent injections resulted in a positive therapeutic response.

Stereoselective disposition of flupentixol: influence on steady-state plasma concentrations in schizophrenic patients.

Steady-state plasma concentrations of cis(Z)-flupentixol (active principle) and trans(E)-flupentixol (inactive) were measured in 41 patients at least on one occasion. Results indicate that concentrations of the trans-isomer are significatively higher. This demonstrates that the two isomers are not handled in the same way by the organism. This may be relevant if plasma level monitoring is performed using non-specific analytical methods.

The Scottish First Episode Schizophrenia Study. II. Treatment: pimozide versus flupenthixol. The Scottish Schizophrenia Research Group.

In a randomised double-blind study, 46 first episode schizophrenics were given pimozide or flupenthixol for up to 5 weeks; the mean daily dose at the end was 18.8 mg pimozide and 20 mg flupenthixol. There were no significant between-drug differences in the effect on mental state or behaviour; positive schizophrenic symptoms responded to treatment, negative symptoms did not. Most patients required anti-Parkinsonian medication. Poor response was associated with 'organicity'. A switch to maintenance therapy after 5 weeks, the outcome of successful treatment and patient cooperation, was achieved in only 54%. There was no relationship between plasma prolactin levels and severity of schizophrenic symptoms in unmedicated patients. Pimozide produced greater elevation of plasma prolactin. Plasma neuroleptic levels showed drug compliance was satisfactory throughout in only 54%.

Neuroleptic serum levels measured by radioreceptor assay in patients receiving intramuscular depot neuroleptics. Some preliminary findings.

Twenty-six chronic schizophrenic patients on well established depot neuroleptic regimes with stable doses (16 on fluphenazine decanoate, ten on flupenthixol decanoate) had serum neuroleptic levels measured by a radioreceptor assay (RRA) method. The assay was sufficiently sensitive to measure serum levels in all cases, with acceptable levels of inter-assay variation. Blood level measurements were repeated on two occasions, at the same time interval from the last injection, in 18 patients (11 on fluphenazine decanoate, seven on flupenthixol decanoate) and remained reasonably stable in most cases, although others showed a wider variation. Despite a wide range of doses (X 32 fluphenazine decanoate, X 21 flupenthixol decanoate) the serum levels fell in a remarkably narrow range (X 4, X 6). There was a significant correlation between dose and blood level for flupenthixol decanoate, but not for fluphenazine decanoate.

Schizophrenia with good and poor outcome. I: Early clinical features, response to neuroleptics and signs of organic dysfunction.

Seventy-seven patients with diagnosis of schizophrenia (62) or schizoaffective disorder (15) were studied 2-20 years since onset of illness, when in a stable condition. The investigation included clinical assessment, measurement of plasma concentrations of neuroleptics and prolactin, computed tomography brain scan, neuropsychological and neurological examination. Outcome of illness was classified according to the presence of chronic psychiatric symptoms and social impairment, and response to neuroleptics according to the effect of treatment in the most recent psychotic episode. Neither outcome nor response to neuroleptics was related to duration of illness. The groups with good and poor outcome differed in premorbid adjustment, age at onset and symptoms of the initial episode, but not in drug bio-availability or prolactin response. Large cerebral ventricles and cognitive impairment, but not neurological 'soft' signs, were associated with unfavourable outcome. The three measures of organicity were not inter-related. No clinical differences were found between chronic patients with and without signs of organic dysfunction. The findings suggest that schizophrenia with good and unfavourable outcome may be separate sub-types. However, the role of organic factors in the latter group remains unclear.

Plasma flupentixol concentrations and clinical response in acute schizophrenia.

Twenty-three acutely psychotic inpatients treated with flupentixol were included in the study. Steady-state plasma concentrations were compared with therapeutic outcome in a routine clinical setting. The threshold concentration for satisfactory antipsychotic effect appeared to be approximately 2 ng/ml. Controlled studies are needed to establish the existence and exact limits of a therapeutic window.