Analysis of the Metabolism of Haloperidol and Its Neurotoxic Pyridinium Metabolite in Patients with Drug-Induced Parkinsonism

• Published in: Neuropsychobiology Vol. 44; no. 3; pp. 126 - 128
• Main Authors: Iwahashi, K., Anemo, K., Nakamura, K., Fukunishi, I., Igarashi, K.
• Format: Journal Article
• Language: English
• Published: Basel, Switzerland Karger 01.01.2001; S. Karger AG
• Subjects: Adult; Adult and adolescent clinical studies; Antipsychotic Agents - metabolism; Biological and medical sciences; Chromatography, Liquid; Female; Haloperidol - blood; Humans; Medical sciences; Parkinsonian Disorders - blood; Parkinsonian Disorders - chemically induced; Pharmacopsychiatry. Main Editor: B. Saletu (Vienna) / Original Paper; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Psychoses; Pyridinium Compounds - blood; Pyridinium Compounds - toxicity; Schizophrenia; Schizophrenia - blood; Spectrometry, Mass, Electrospray Ionization; Vitamin E; HPP; Haloperidol; Psychosis; Human; Parkinsonism; Investigation method; Psychotropic; Metabolite; Secondary effect; Schizophrenia; Chromatography; Extrapyramidal syndrome
• ISSN: 0302-282X; 1423-0224
• DOI: 10.1159/000054931

The blood levels of the neurotrophic drug haloperidol (HP) and its pyridinium metabolite, HPP + , have been analyzed by liquid chromatography/electrospray ionization-mass spectrometry in 10 schizophrenic patients treated with HP, without carbamazepine (HP, oral daily dose of 0.3–0.5 mg/kg body weight for more than 1 year, females, aged 41 ± 8.5 years). There was a significant difference (t-test, d.f. = 8, p (t₀ = 7.2) <0.005) in the blood HPP + level between the 5 patients with (18.5 ± 6.4 ng/ml) and the 5 without (6.3 ± 2.4 ng/ml) severe side effects such as drug-induced parkinsonism (Extrapyramidal Symptom Rating Scale (ESRS) parkinsonism severity scores 2.8 ± 1.5 and 1.8 ± 1.1, respectively). Moreover, it is suggested that vitamin E may be effective for drug-induced parkinsonism through a change in the blood HPP + level. It is necessary to investigate the HPP + metabolism in psychiatric patients to avoid severe side effects such as drug-induced parkinsonism and cardiac functional disorders.