• Korean Journal of Biological Psychiatry
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• v.5 no.1
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• pp.114-121
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• 1998

Bethanechol, a cholinergic agonist, has been recommended for the management of peripheral anticholinergic side effects during the treatment of antipsychotic medications. But there have been few studies which have evaluated the drug interactions of antipsychotics and bethanechol, even the treatment effects of bethanechol on anticholinergic side effects. So the authors have evaluated whether psychopathology and plasma haloperidol and reduced haloperidol concentrations are significantly changed or not when bethanechol was administrated with maintained doses of haloperidol and other coadministrated drugs(such a benztropine). Also we have evaluated the abating effects of bethanechol on anticholinergic side effects during the treatment with haloperidol. Fifteen schizophrenics with higher than 5 of total score of anticholinergic side effects of 'Rating scale for side effect' were assigned to two groups, and bethanechol 30mg/day and 60mg/day were applied on each group for 4 weeks. The daily haloperidol dosages were fixed before 2 weeks of study. We assessed anticholinergic side effects by 'Rating scale for side effect' and psychopathology by BPRS, and plasma haloperidol and reduced haloperidol concentrations by HPLC at baseline, 2nd week and 4th week. The results were as followed, 1) there was no significant change of plasma haloperidol and reduced haloperidol concentration, 2) at baseline, the dosage of haloperidol showed significant correlation with the total score of anticholinergic side effect, but not at 2nd week and 4th week, 3) in 60mg/day group, dry mouth and the total score of anticholinergic side effects were significantly improved, but not in 30mg/day group, 4) there was no significant change of BPRS except withdrawal at 2nd week. These results suggest that coadministration of bethanechol influenced neither on psychopathology nor on plasma haloperidol and reduced haloperidol concentrations and that improved dry mouth and total score of anticholinergic side effects at 60mg/day.

• Journal of Pharmaceutical Investigation
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• v.22 no.3
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• pp.197-204
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• 1992

A gas chromatographic method using nitrogen phosphorous selective detection was developed for simultaneous determination of haloperidol and its metabolite, reduced haloperidol, in human plasma. Combelen was used as internal standard, The method involved extraction and trimethylsilylation followed by the injection of $2-4\;{\mu}l$ of benzene layer, which was used to dissolve the trimethylsilylated derivatives of haloperidol and reduced haloperidol, onto SE-54 column [5% phenyl methyl silica fused capillary column, $16m{\times}0.22\;mm$ $(I.D.){\times}0.33\;{\mu}m$ (coated thickness)]. The temperature of column oven was programmed from $200^{\circ}C\;to\;300^{\circ}C$ at the increase rate of $10^{\circ}C/min and also the temperatures of injector and detector were set at $300^{\circ}C$. Helium was used as carrier gas and its flow rate was maintained at 30 ml/min. The detection was conducted with nitrogen phosphorous selective detector. The retention times for combelen, reduced haloperidol and haloperidol were found to be 9.14, 9.75 and 9.99 min, respectively. The detection limits for haloperidol and reduced haloperidol in human plasma were both 0.2 ng/ml. The coefficients of variation of the intra-assay were generally low (below 9.8%). The mean absolute recoveries of added haloperidol and reduced haloperidol from plasma were 72% and 84%, respectively. No interferences from endogenous substances were found.

• Korean Journal of Biological Psychiatry
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• v.3 no.2
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• pp.251-257
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• 1996

Selective serotonin reuptake inhibitors(SSRIs), as haloperidol, ore metabolized in the cytochrome P450IID6. They can cause inhibition of metabolism of antipsychotics to elevate the serum level of antipsychotics and exacerbate the extrapyramidal symptoms when co-administered with antipsychotics. Among these SSRIs, there ore a few studies about paroxetine compared to fluoxetine or sertraline. In this study, we have intended to know the drug interaction of paroxetine and haloperidol when co-administered two drugs for the chronic schizophrenics by assessing the changes of positive, negative symptoms and extrapyramidal symptoms. for this purpose, we selected 29 subjects, the chronic schizophrenics with no physical problems. They were under maintenance therapy of haloperidol. They ore randomly assigned to placebo group(n=12) and drug group(n=17) by using double blind method. And then, placebo or paroxetine 20mg were administered to the subjects of each groups during 8 week period. We have assessed their psychopathology and extrapyramidal symptoms using Positive and Negative Syndrome Scale(PANSS), Hamilton Rating Scale lor Depression(HRSD), Simpson-Angus Scale at 0, 2, 4, 6, 8 weeks and serum haloperidol, reduced haloperidol levels at 0, 4, 8 weeks during the period. The results ore analysed by using repeated measure MANOVA. 27 subjects have completed the study during 8 weeks. among the subjects, 1) PANSS, HRSD ; no significant difference between groups. 2) Simpson-Angus Scale ; no significant change according to the time and no significant difference between the groups(no group and time effect). 3) Haloperidol and reduced haloperidol level ; no significant change. When co-administered paroxetine and haloperidol, there ore no significant changes of the psychopothology and no significant changes of the extrapyramidal symptoms. In this result, paroxetine seems to be not to affect the metabolism of haloperidol.

• Journal of Pharmaceutical Investigation
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• v.23 no.3
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• pp.165-177
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• 1993

The relationship between the plasma haloperidol (HP) concentration and clinical response, and the effects of its active metabolite, reduced haloperidol (RH) on clinical response of HP were investigated in schizophrenic patients. In clinical study I, with 17 schizophrenic patients (male 8, fermale 9) who were administered with three different fixed doses of HP (15, 30 and 50 mg/day) for 3 weeks, the concentrations of HP and RH in plasma and blood and clinical response had been checked before and every week during the study. The clinical response was evaluated by the method of brief psychiatric rating scale (BPRS), and relative improvement of clinical response based on baseline BPRS (before drug treatment) was calculated. The concentrations of HP and RH in plasma and blood were assayed by HPLC. In clinical study II, the plasma RH/HP concentration ratios were checked in 11 patients who were administered with high doses of HP, over 60 mg a day, because of the poor clinical response at usual doses of HP. Plasma HP concentration and relative improvement of BPRS at 3 week in schizophrenic patients showed a 'curvilinear' relationship, and the clinical response was improved relatively over 50% based on the baseline BPRS in the range of $5{\sim}57\;ng/ml $ of HP in plasma. Also, the plasma RH concentrations were increased nonlinearly as the plasma HP concentration increased, and in high plasma HP concentration, over 30 ng/mI, clinical response gradually decreased, while the plasma RH/HP concentration ratio increased nonlinearly. Blood partition coefficients of HP and RH were not changed according to daily HP dose and duration of drug therapy. From these results, it is noted that the higher plasma RH/HP concentration ratio, resulted from the accumulation of RH as HP concentration increased, might explain the 'curvilinear' decrease of HP clinical response.

• Korean Journal of Biological Psychiatry
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• v.8 no.1
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• pp.79-84
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• 2001

Objectives : To investigate the effects of (-)-3-PPP(0.5, 2, and 10mg/kg, s.c.) and haloperidol(0.1, 0.5, and 2mg/kg, s.c.) on the extracellular dopamine concentrations, and the effect of pretreatment with (-)-3-PPP(2mg/kg) on the haloperidol(2mg/kg)-induced extracellular dopamine concentrations in the nucleus accumbens(NAS) of free moving rats. Methods : Dopamine levels in dialysate were determined with high pressure liquid chromatography(HPLC) with electrochemical detection(ECD). Results : (1)(-)-3-PPP had dual actions depending on the doses: at 2mg/kg, it decreased and at 10mg/kg, increased extracellular dopamine concentrations ; (2) haloperidol at all doses increased dopamine levels with higher dose having a greater increase; and (3) pretreatment of (-)-3-PPP reduced the increase in dopamine levels elicited by acute treatment with haloperidol. Conclusions : These findings suggest that pretreatment of (-)-3-PPP in low dose could accelerate the onset of therapeutic effect of haloperidol by diminishing the haloperidol-induced dopamine release in the limbic system.

• YAKHAK HOEJI
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• v.34 no.6
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• pp.375-383
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• 1990

The pharmacokinetics of haloperidol were determined after single oral and intravenous doses in 13 male schizophrenic patients. Plasma concentrations of haloperidol(HP) and reduced haloperidol(RH) were measured by high performance liquid chromatography. Plasma concentration data obtained were analyzed by obth model dependent (one-or two exponential decay models using nonlinear regression) and model independent (AUC and first moment curve) approaches. The two methods were found to be in close results. After intravenous injections of HP in 8 patients (10 mg/man), the mean central and peripheral volume of distributions were $2.85\;{\pm}\;1.70$ and $8.09\;{\pm}\;2.10\;l/kg$, respectively, and mean steady state volume of distribution was $11.87\;{\pm}\;3.21\;l/kg$. Mean clearance, MRT and elimination half life were $12.39\;{\pm}\;3.25\;ml/min/kg$, $925.10\;{\pm}\;166.79\;min$ and $676.35\;{\pm}\;126.45\;min$, respectively. After oral administrations of HP in 5 patients, mean peak time and peak concentration were $217.63\;{\pm}\;61.60\;min$ and $9.77\;{\pm}\;2.92\;ng/ml$, respectively. Mean MRT and elimination half life were $1112.23\;{\pm}\;131.73\;min$ and $724.02\;{\pm}\;120.03\;min$, respectively, and these parameters were not significantly different from those of intravenous injection of HP. Absolute bioavailability of HP oral product was found to be about 44%. The profiles of plasma RH concentration-time curves after oral or intravenous doses of HP were similar. Also it was found that the elimination rate of RH was solwer than that of HP by comparing the slopes of plasma concentration-time curves of HP and RH.

• Animal cells and systems
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• v.4 no.2
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• pp.173-179
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• 2000

Evidence suggested that atypical antipsychotics (APs) such as clozapine show less side effects than those of typical APs such as haloperidol and sulpiride. However, little is known about chronic effects of these drugs on changes in gonadotropin releasing hormone (GnRH) mRNA expression and luteinizing hormone (LH) immunoreactivity. Male rats were divided into water-, haloperidol-, sulpiride-, and clozapine-treated groups, and these drugs were administered orally for 4 weeks. The changes in the expression of GnRH mRNA and the LH immunoreactivity were determined in the hypothalamus and pituitary, respectively, using in situ hybridization and immunohistochemistry. GnRH mRNAs were clearly expressed in the water-treated control vats. This was significantly reduced by the chronic treatments with the typical APs, especially with haloperidol, but not with atypical APs clozapine. Likewise, LH immunoreactivity was clearly stained in the control group. While its immunoreativity was significantly reduced by the chronic APs treatments, clozapine treatment showed only slight attenuation. The results show that the atypical APs clozapine has less side effects in the gonadal function than the typical APs haloperidol and the sulpiride. These results suggest that clozapine is a safer drug than the typical APs, at least in the reproductive system.

• Korean Journal of Biological Psychiatry
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• v.5 no.2
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• pp.263-277
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• 1998

Conventional high-dose antipsychotics tend to result in more side effects, negative symptoms and dysphoria, and at the same time lower the cognitive function which is already impaired in most schizophrenics. Florid psychotic symptoms, negative symptoms and cognitive impairment greatly impede psychosocial performance and eventual reintegration into society. The reduction of symptom and the improvement of cognitive funtions and social skills are therefore central to the psychiatric rehabilitation process. The purpose of this study was to evaluate the dose-reduction effects of antipsychotics on chronic schizophrenics prescribed conventional high-dose antipsychotics more than 1,500mg equivalent of chlorpromazine. Fifty-one chronic schizophrenics who maintained high-dose antipsychotics for more than three months were randomly assigned to two groups : 20 patients comprised the dose-maintaining group and 31 patients made the dose-reduction group. Over a sixteen weekperiod Positive and Negative Syndrome Scale(PANSS), Extrapyramidal Symptom(EPS), Nurses' Observation Scale for Inpatient Evaluation(NOSIE-30), Continuous Performance Test(CPT), Quality of Life(QOL), and haloperidol/reduced haloperidol blood levels were determined at the base line and after 2, 4, 6, 8, 12, 16 weeks to evaluate the dose reduction effects of high-dose antipsychotics. The results were as follows : 1) Dose-reduction is highly effective in reducing positive and negative symptoms, and general psychopathology. Effects were most prominent at 8, 12, 16 weeks. Among the dose reduction group, positive symptoms in positive symptom group and negative symptoms in negative symptom group were more reduced. 2 Extrapyramidal symptoms showed no significant difference between two groups. But the EPS was reduced time after time within two groups. 3) Hit rates of Continuous Performance Test, which indicate attentional capacity, increased significantly after dose reduction. 4) Haloperidol and reduced haloperidol blood levels decreased until the 4th week, after which they were constant. 5) Total scores of Nurses' Observation Scale for Inpatient Evaluation were unchanged between the two groups. But among the indices, social interest and personal neatness were improved in the dose-reduction group and retardation was aggrevated in the dose-maintaining group. 6) Total quality of life scores were unchanged between two groups. But in the dose maintaining group, satisfaction scores of attention, autonomy, and interpersonal relationship decreased progressively. These findings suggest that the dose reduction of antipsychotics for chronic schizophrenics on programs of high-dose antipsychotics were effective. Dose reduction should therefore be implemanted to spread the rehabilitation and improve quality of life for chronic schizophrenics.

• Korean Journal of Biological Psychiatry
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• v.6 no.1
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• pp.74-80
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• 1999

This study was performed to investigate the mechanism of the clozapine-induced seizures in partially restrained rats by concomitant treatment with drugs affecting monoaminergic systems. Partially restrained rats treated with acute single doses of 10mg/kg clozapine exhibited myoclonic jerks (MJs). Drugs affecting the monoaminergic systems, including 2mg/kg haloperidol, 5mg/kg propranolol, 2mg/kg ritanserin, 20mg/kg fluoxetine, and 20mg/kg imipramine, were concomitantly treated with clozapine to observe the effects of these drugs on the MJs. The drugs were given intraperitoneally either as acute single doses(haloperidol, propranolol, ritanserin, and fluoxetine) or as chronic doses for 21days(haloperidol, imipramine, ritanserin, and fluoxetine). The effects of the concomitant treatment of other drugs on the clozapine-induced MJs were evaluated by comparison of the total numbers of the MJs between the clozapine-treated and concomitantly treated groups. The results were as follows. 1) Concomitant treatment with acute single doses of haloperidol, propranolol, and fluoxetine reduced the total numbers of the clozapine-induced MJs, while concomitant treatment with ritanserin did not. 2) Concomitant treatment with chronic doses of imipramine and ritanserin increased the total numbers of the MJs, while concomitant treatment with fluoxetine reduced them. Concomitant chronic treatment with haloperidol did not affect the numbers of the MJs. These results suggest that dopamine and serotonin, not noradrenalin may be involved in the clozapine-induced MJs in partially restrained rats. Future research needs to study the function of each subtype of monoaminergic receptors on the mechanism of the clozapine-induced seizure.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1992.05a
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• pp.63-63
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• 1992

할로페리돌(HP)은 정신분열증 환자에 널리 사용되는 Dopamine D$_2$-receptor의 antagonist인 antipsychotic drug이다. 이 약물의 혈장농도와 임상 반응사이의 'curvilinear'한 상관성 존재여부와 여기에 대한 대사체(reduced haloperidol, RH)의 영향에 대해 논란은 많지만, 본 연구 팀에서도 위의 상관성이 존재하며 또한 여기에 RH가 영향을 미칠 것으로 보고한바 있다. 따라서 본 연구에서는 앞의 결과에 대한 기전을 밝히고, 궁극적으로 효율적인 뇌송달 시스템의 개발가능성을 검토하기위한 1차적 인구로 HP의 약물속도론적 연구를 사람, 랫트 및 가토에서 실시하여 그특성을 비교하였다. 사람경우는 13명의 정신분열증 초기환자를 대상으로 경구(20mg HP, 5명) 및 주사(10mg HP, 8명) 투여한 후, 또한 랫트 및 가토의 경우는 마리당 5mg의 HP 및 RH를 각각 정맥주사한 후 경시적으로 혈장중 HP 및 RH의 농도를 측정하여 체내동태 특성을 검토하였다.