• 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.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.

• 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.