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Response of patients with treatment-refractory schizophrenia to clozapine within three serum level ranges
- Source :
- The American journal of psychiatry. 153(12)
- Publication Year :
- 1996
-
Abstract
- Objective : This study sought to determine the relationships between serum clozapine levels and therapeutic response. Method : Fifty-six inpatients who met the DSM-III-R criteria for chronic schizophrenia and who had not responded to extended treatment with classical antipsychotics were randomly assigned to 12 weeks of double-blind treatment with clozapine at one of three serum level ranges : low (50-150 ng/ml), medium (200-300 ng/ml), or high (350-450 ng/ml). Baseline clinical assessments were completed before the patients' regular antipsychotic and anticholinergic drugs were discontinued. During clozapine treatment, serum levels were ascertained weekly to allow adjustment of clozapine doses so as to maintain each patient near the midpoint of his or her assigned serum level range. Clinical assessments were completed after 6 and 12 weeks of treatment. Results : The analyses of the results of treatments supported the superior efficacy of the 200-300 ng/ml and 350-450 ng/ml serum clozapine level ranges over the 50-150 ng/ml range, with no advantage for 350-450 ng/ml over 200-300 ng/ml. Sleepiness increased with increasing serum levels. Conclusions : Serum clozapine levels per unit of daily dose were at the lower end of the range noted in previous reports, possibly reflecting the current study's dosing schedules of twice or three times a day, the 11- to 13-hour postdose sampling time, and the moderate doses given. Serum clozapine levels, if interpreted in relation to daily clozapine dosing schedules, postdose sampling time, and total daily dose, may help to guide dosing to provide adequate opportunities for therapeutic response and to limit certain side effects of clozapine treatment.
- Subjects :
- medicine.medical_treatment
Drug Administration Schedule
law.invention
Randomized controlled trial
Double-Blind Method
law
medicine
Humans
Dosing
Antipsychotic
Clozapine
Psychiatric Status Rating Scales
Chemotherapy
Dose-Response Relationship, Drug
business.industry
medicine.disease
Clinical trial
Hospitalization
Psychiatry and Mental health
Dose–response relationship
Treatment Outcome
Schizophrenia
Anesthesia
Schizophrenic Psychology
business
medicine.drug
Subjects
Details
- ISSN :
- 0002953X
- Volume :
- 153
- Issue :
- 12
- Database :
- OpenAIRE
- Journal :
- The American journal of psychiatry
- Accession number :
- edsair.doi.dedup.....3da713f436a6f5c0e279a255c70ba73f