title: An epidemiological study of concomitant use of Chinese medicine and antipsychotics in schizophrenic patients: implication for herb-drug interaction.
abstract: BACKGROUND
  Herb-drug interactions are an important issue in drug safety and clinical practice. The aim of this epidemiological study was to characterize associations of clinical outcomes with concomitant herbal and antipsychotic use in patients with schizophrenia.
  
  
  RESULTS
  In this retrospective, cross-sectional study, 1795 patients with schizophrenia who were randomly selected from 17 psychiatric hospitals in China were interviewed face-to-face using a structured questionnaire. Association analyses were conducted to examine correlates between Chinese medicine (CM) use and demographic, clinical variables, antipsychotic medication mode, and clinical outcomes. The prevalence of concomitant CM and antipsychotic treatment was 36.4% [95% confidence interval (95% CI) 34.2%-38.6%]. Patients using concomitant CM had a significantly greater chance of improved outcomes than non-CM use (61.1% vs. 34.3%, OR = 3.44, 95% CI 2.80-4.24). However, a small but significant number of patients treated concomitantly with CM had a greater risk of developing worse outcomes (7.2% vs. 4.4%, OR = 2.06, 95% CI 2.06-4.83). Significant predictors for concomitant CM treatment-associated outcomes were residence in urban areas, paranoid psychosis, and exceeding 3 months of CM use. Herbal medicine regimens containing Radix Bupleuri, Fructus Gardenia, Fructus Schisandrae, Radix Rehmanniae, Akebia Caulis, and Semen Plantaginis in concomitant use with quetiapine, clozapine, and olanzepine were associated with nearly 60% of the risk of adverse outcomes.
  
  
  CONCLUSIONS
  Concomitant herbal and antipsychotic treatment could produce either beneficial or adverse clinical effects in schizophrenic population. Potential herb-drug pharmacokinetic interactions need to be further evaluated.
authors.affiliation: School of Chinese Medicine, Faculty of Medicine, the University of Hong Kong, Hong Kong, China. zhangzj@hku.hk
authors.forename: Zhang-Jin
authors.initials: ZJ
authors.lastname: Zhang
authors.forename: Qing-Rong
authors.initials: QR
authors.lastname: Tan
authors.forename: Yao
authors.initials: Y
authors.lastname: Tong
authors.forename: Xue-Yi
authors.initials: XY
authors.lastname: Wang
authors.forename: Huai-Hai
authors.initials: HH
authors.lastname: Wang
authors.forename: Lai-Ming
authors.initials: LM
authors.lastname: Ho
authors.forename: Hei Kiu
authors.initials: HK
authors.lastname: Wong
authors.forename: Yi-Bin
authors.initials: YB
authors.lastname: Feng
authors.forename: Di
authors.initials: D
authors.lastname: Wang
authors.forename: Roger
authors.initials: R
authors.lastname: Ng
authors.forename: Grainne M
authors.initials: GM
authors.lastname: McAlonan
authors.forename: Chuan-Yue
authors.initials: CY
authors.lastname: Wang
authors.forename: Vivian Taam
authors.initials: VT
authors.lastname: Wong
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D003131:Combined Modality Therapy / Q000009:adverse effects; D003430:Cross-Sectional Studies; D004365:Drugs, Chinese Herbal / Q000627:therapeutic use*; D016021:Epidemiologic Studies; D005260:Female; D041743:Herb-Drug Interactions / Q000502:physiology*; D006801:Humans; D008297:Male; D008516:Medicine, Chinese Traditional / Q000009:adverse effects / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012559:Schizophrenia / Q000188:drug therapy* / Q000453:epidemiology*; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents; D004365:Drugs, Chinese Herbal