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.

Injectable long-term control-released in situ gels of hydrochloric thiothixene for the treatment of schizophrenia: preparation, in vitro and in vivo evaluation.

Hydrochloric thiothixene (HT) is an antipsychotic drug used in the treatment of various psychoses including schizophrenia, mania, polar disorder, and in behavior disturbances. However, because the psychotics often could not control their behaviors, the independent administration of antipsychotic drug based on medical order was difficult. The omissions of the administration often brought an unsatisfactory therapeutic efficacy. A novel injectable long-term control-released in situ gel of HT for the treatment of schizophrenia was developed based on biodegradable material polylactic acid (PLA). The optimum formulation of the injectable PLA-based HT in situ gel containing 15% (w/w) HT and 45% (w/w) PLA with benzyl benzoate was used as a gelling solvent. The results of the in vitro and in vivo studies showed that this in situ gel had a long-term period of drug release for several weeks and a good histocompatibility without any remarkable inflammatory reactions.

Simultaneous UPLC-MS/MS assay for the detection of the traditional antipsychotics haloperidol, fluphenazine, perphenazine, and thiothixene in serum and plasma.

BACKGROUND: Most antipsychotic drugs that are commonly prescribed in the USA are monitored by liquid and gas chromatographic methods. Method performance has been improved using ultra high pressure liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). A rapid and simple procedure for monitoring haloperidol, thiothixene, fluphenazine, and perphenazine is described here. METHOD: Antipsychotic drug concentrations in serum and plasma were determined by LCMS/MS (Waters Acquity UPLC TQD). The instrument is operated with an ESI interface, in multiple reaction monitoring (MRM), and positive ion mode. The resolution of both quadrupoles was maintained at unit mass with a peak width at half height of 0.7amu. Data analysis was performed using the Waters Quanlynx software. Serum or plasma samples were thawed at room temperature and a 100µL aliquot was placed in a tube. Then 300µL of precipitating reagent (acetonitrile-methanol [50:50, volume: volume]) containing the internal standard (0.12ng/µL Imipramine-D3) was added to each tube. The samples were vortexed and centrifuged. The supernatant was transferred to an autosampler vial and 8µL was injected into the UPLC-MS/MS. Utilizing a Waters Acquity UPLC HSS T3 1.8µm, 2.1×50mm column at 25ºC, the analytes were separated using a timed, linear gradient of acetonitrile and water, each having 0.1% formic acid added. The column is eluted into the LC-MS/MS to detect imipramine D3 at transition 284.25>89.10, haloperidol at 376.18>165.06, thiothixene at 444.27>139.24, fluphenazine at 438.27>171.11, and perphenazine at 404.19>143.07. Secondary transitions for each analyte are also monitored for imipramine D3 at 284.25>193.10, haloperidol at 376.18>122.97, thiothixene at 444.27>97.93, fluphenazine at 438.27>143.08, and perphenazine at 404.19>171.11. The run-time is 1.8min per injection with baseline resolved chromatographic separation. RESULTS: The analytical measurement range was 0.2 to 12.0ng/mL for fluphenazine and perphenazine, and was 1 to 60.0ng/mL for haloperidol and thiothixene. Intra-assay and inter-assay imprecisions (CV) were less than 15% at two concentrations for each analyte. CONCLUSIONS: By utilizing a LC-MS/MS method we combined two previously established analytical assays into one, yielding a 75% time-savings on set-up, and a significantly shortened analytical run-time. These changes reduced the turn-around time for analysis and eliminated interference issues resulting in fewer injections and increased column lifetime.

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.

The effect of paroxetine on thiothixene pharmacokinetics.

OBJECTIVE: In this study healthy volunteers received thiothixene with and without a 3-day pretreatment with paroxetine to determine if paroxetine decreased the clearance of thiothixene. METHOD: Ten healthy medication-free volunteers (4 women and 6 men, mean age 38 +/- 12 years) were randomized to receive a single 20 mg oral dose of thiothixene on two separate occasions. On one occasion thiothixene was given concurrently, and following 3 days of pre-treatment with oral paroxetine (20 mg/day). On the other occasion thiothixene was given without paroxetine pre-treatment. The two study days were separated by a minimum period of 2 weeks. On both study days, after the administration of thiothixene, 10 ml blood samples were collected over the next 72 h. RESULTS: None of the pharmacokinetic parameters of thiothixene were significantly altered by a 3-day treatment with paroxetine. DISCUSSION: It is likely that the CYP2D6 isoenzyme is not responsible for a high proportion of thiothixene clearance, but one cannot exclude the possibility that a longer paroxetine pretreatment might have caused some inhibition of thiothixene clearance.

A simple, sensitive liquid chromatographic assay of cis-thiothixene in plasma with coulometric detection.

A novel, simple, and very sensitive liquid-chromatographic assay with a coulometric detector has been developed for quantitating cis-thiothixene (CTX) in human plasma. A reverse phase, 5-microns cyano column (25 x 0.46 cm), a mobile phase of phosphate buffer (pH 2.5) and acetonitrile (40/60 by vol), and a coulometric detector are used for the separation of CTX, and the internal standard, trifluoperazine. CTX and trifluoperazine are extracted from alkalinized plasma into n-pentane-isopropanol (95/5 by vol) and purified by back extraction into perchloric acid. The optimum oxidation potential for the analytes is +0.8 V versus an Ag/AgCl electrode. The detection limit for CTX is 200 pg using 1 mL of plasma and CTX concentrations are linear from 0 to 40 micrograms/L. The average interassay CV is 9%, and the mean recovery is 99% relative to the internal standard. Possible interferences from various psychiatric and common drugs in the assay have been studied. The assay method was validated by determining the concentration of CTX in the plasma of 100 schizophrenic patients.

Neuroleptic plasma levels.

There is enormous variation in plasma levels of most neuroleptics in patients on the same dose. Much of the past research on the relation between plasma levels of antipsychotic drugs and clinical change, however, has been difficult to interpret. It does appear that decreased bioavailability, at least in public institutions, is rarely the cause of treatment failure. Aberrantly low plasma levels are more likely due to surreptitious noncompliance or drug interactions with enzyme inducers such as carbamazepine. Therapeutic plasma level ranges, in which good antipsychotic effect occurs without undue side effects, have been tentatively identified for perphenazine, haloperidol, fluphenazine, and chlorpromazine. The extent to which aberrantly high plasma levels are associated with inferior antipsychotic response is unclear. Antipsychotic plasma levels may be most useful when the distinction between side effects and worsening psychosis is unclear. The utility of high neuroleptic plasma levels in the treatment-resistant patient is unclear.

Improved high-performance liquid chromatographic method for the determination of tiotixene in human serum.

The problem of accurate determination of tiotixene in body fluids is still challenging. Several methods have been published but most of them require a tedious, time-consuming sample preparation, are not specific enough and lack the necessary sensitivity or require highly sophisticated analytical devices. As carefully validated analytical methods represent the basis of conclusive clinical trials (e.g. evaluating bioavailability/bioequivalence), an assay was developed to fulfill these needs. The method present employs an HPLC system combined with a UV-detector and uses perazine as an internal standard. The achieved lower limit of detection in serum was 0.05 ng/ml and the calibration curves were linear in the range of 0.5-20 and 0.1-2.0 ng/ml, respectively. The chromatographic peaks were well resolved and the cis-/transisomers well separated. The imprecision and inaccuracy data typically ranged from 2 to 7%; the recovery from serum was always better than 80%. The assay has been successfully used for the determination of very low tiotixene serum levels during several clinical studies.

Quantitation of thiothixene in plasma by high-performance thin-layer chromatography and fluorometric detection.

A specific and sensitive assay procedure to measure thiothixene (Navane) in plasma has been developed and used to measure plasma concentrations in patients receiving thiothixene. The procedure involves in situ fluorescent detection after separation by high-performance thin-layer chromatography. Fluorescent detection permits a limit of detectability of approximately 0.1 ng/ml in plasma and the coefficient of variation is less than 6% at 2 ng/ml. Thirty samples may be processed through the entire procedure in less than 6-h period and up to 60 samples may be simultaneously spotted and chromatographed with a larger-capacity spotter and plate. Plasma levels (n = 62) drawn 10-12 h after dosage ranged from 0 to 42 ng/ml from dosages of 4-100 mg/day.

Tardive dyskinesia and steady-state serum levels of thiothixene.

The purpose of this investigation was to determine the relationship between serum levels of the neuroleptic agent thiothixene and tardive dyskinesia in schizophrenics of a wide age range. Forty-one male schizophrenic subjects, 21 with tardive dyskinesia and 20 without, were given a fixed dosage of thiothixene hydrochloride (10 mg orally four times daily) after a drug-free period of one week. Higher steady-state serum levels of thiothixene (obtained after five days of a fixed-dosage schedule) were associated with greater degrees of tardive dyskinesia. This relationship was independent of the relationship between tardive dyskinesia and age.

Psychotropic blood levels: a guide to clinical response.

In the clinical use of psychotropic drugs, the value of blood level monitoring remains uncertain because, for most of these agents, consistent, predictable correlations between blood level and therapeutic response have not been established. In recent years productive work has been done in this area which suggests that, in certain clinical situations and with certain psychotropic agents, monitoring of blood levels may be a useful component of patient care. The literature regarding blood levels and therapeutic response to various psychotropic drugs is reviewed and some of the clinical settings in which blood levels are, in fact, predictive of therapeutic response in the management of psychiatric illness are discussed.

Plasma level monitoring of antipsychotic drugs. Clinical utility.

The steady-state plasma concentrations of antipsychotic drugs show large interpatient variations but remain relatively stable from day to day in each individual patient. Monitoring of antipsychotic drug concentrations in plasma might be of value provided the patients are treated with only 1 antipsychotic drug. Some studies have reported a relationship between therapeutic response and serum antipsychotic drug 'concentrations' as measured using the radioreceptor assay (RRA) method, which measures dopamine receptor-blocking activity in plasma. Most studies, however, have failed to demonstrate such a relationship, and the RRA does not seem to provide the generally useful tool for plasma concentration monitoring of antipsychotic drugs that was hoped for initially. A lack of correlation between dopamine receptor-blocking activity in plasma and therapeutic response may be due to differences in the blood-brain distribution of both antipsychotic drugs and their active metabolites. Chemical assay methods (e.g. GLC and HPLC) have been used in studies which examined the relationships between therapeutic response and antipsychotic drug concentrations in red blood cells and in plasma. It seems that for these drugs, measuring red blood cell concentrations does not offer any significant advantage over measuring plasma concentrations. Reasonably controlled studies of plasma concentration-response relationships using randomly allocated, fixed dosages of chlorpromazine, fluphenazine, haloperidol, perphenazine, sulpiride, thioridazine and thiothixene have been published but often involve relatively few patients. A correlation between therapeutic response and plasma concentrations of thioridazine and its metabolites has not been demonstrated, and plasma level monitoring of thioridazine and its metabolites therefore appears to have no clinical value. Clinical behavioural deterioration concomitant with high plasma concentrations of chlorpromazine and haloperidol have been reported. A dosage reduction might be considered after 2 to 4 weeks' treatment in non-responders who have plasma chlorpromazine concentrations above 100 to 150 micrograms/L or plasma haloperidol concentrations above 20 to 30 micrograms/L. Non-responders and good responders to chlorpromazine treatment, however, have plasma drug concentrations in the same range, and a therapeutic range of plasma chlorpromazine levels has not been defined. Therapeutic plasma haloperidol concentrations (i.e. 'window') in the range of 5 to 20 micrograms/L have been reported by some investigators, but others have found no such relationship.(ABSTRACT TRUNCATED AT 400 WORDS)

The strategy and value of neuroleptic drug monitoring.

The concept of monitoring neuroleptic drugs by means of chemical or pharmacological assays is considered from a historical and strategic point of view. The objectives of compliance control, reduction of long-term exposure, titration to a therapeutic range, and solution of medicolegal problems are separately considered. The relative merits of chemically specific (mainly chromatographic) and clinically specific (radioreceptor) assays are considered. An algorithm for interpretation of a neuroleptic concentration measurement is presented.

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.

Acute thiothixene overdose.

An acute thiothixene intoxication is presented. Blood thiothixene concentration of 0.52 mg/L was detected before it declined to 0.047 mg/L in 12 hrs. Analysis was by thin layer chromatography, ultraviolet spectrophotometry, and fluorescence spectrophotometry.

Clinical relevance of thiothixene plasma levels.

The authors examined plasma levels of thiothixene and clinical response in 19 DSM-III diagnosed inpatient schizophrenics, using an improved methodology. A significant curvilinear correlation was demonstrated between clinical response and plasma levels for thiothixene (p less than 0.02). Optimal clinical response to thiothixene appears to be associated with plasma levels from 2.0 to 15.0 ng/ml (p less than 0.05). These findings suggest that laboratory measurement of thiothixene levels may assist in determining the minimum effective dose for individual patients.

Drug-refractory chronic schizophrenics: doses and plasma concentrations of thiothixene.

Some treatment-resistant schizophrenics will respond to rather large doses of thiothixene, such as 120 to 400 mg/day. These patients also show higher plasma concentrations (24 to 57 ng/ml) of the drug than those who respond less well. Patients tolerated this intensive treatment equally well as more conservative programs. Chronic refractory schizophrenics may benefit from such intensive treatment in the short term, but one cannot yet be certain about long-term effects.

Correlates of dangerous behavior by schizophrenics in hospital.

An evaluation of correlates of inpatient dangerous behavior in a schizophrenic population is presented. Potential correlates included: neuroleptic serum levels, admission schizophrenic symptoms on the Brief Psychiatric Rating Scale (BPRS), act leading to admission, military experience, and childhood discipline. A multiple regression analysis indicated that the best correlate of inpatient physical assaults, verbal assaults, and total number of inpatient dangerous acts in our population was low neuroleptic serum levels. The best predictor of seclusion and restraint was severity of Vietnam combat. Additional significant correlates included degree of schizophrenic symptoms on the BPRS and history of violence prior to admission. Three factors: neuroleptic serum level, degree of schizophrenic symptoms, and violence prior to admission accounted for 49% of the sample variance for inpatient assaults.