title: Serum concentrations of cycloserine and outcome of multidrug-resistant tuberculosis in Northern Taiwan.
abstract: BACKGROUND
  Therapeutic drug monitoring (TDM) has been advocated to promote the efficacy of anti-tuberculosis agents. Cycloserine (CS) is a second-line anti-tuberculosis drug whose serum concentrations in tuberculosis (TB) patients are largely unknown.
  
  
  OBJECTIVE
  To investigate serum CS concentrations after drug ingestion in TB patients.
  
  
  METHODS
  Multidrug-resistant TB patients who were taking CS in a tertiary care centre in northern Taiwan between 1 April 2009 and 31 October 2009 were enrolled in the study. Serum CS concentrations were measured at 2 and 6 h after drug administration.
  
  
  RESULTS
  Of 32 patients enrolled, 23 were males and 9 females. The mean CS dose was 8.8 ± 1.3 mg/kg. The mean serum concentrations at 2 and 6 h were respectively 19.7 ± 8.3 and 18.1 ± 8.7 μg/ml. Seven patients (22%) had serum drug concentrations that were higher at 6 h than at 2 h, 12 (38%) had peak serum concentrations within the recommended range of 20-35 μg/ml; 18 patients (56%) had concentrations <20 μg/ml at both 2 h and 6 h; and 2 patients (6%) had at least one measurement >35 μg/ml.
  
  
  CONCLUSIONS
  Lower than recommended serum CS concentrations and delayed absorption were common. It is essential to develop practical TDM to maintain proper serum drug concentrations.
authors.affiliation: Division of Pulmonary Medicine, Departments of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
authors.forename: W-Y
authors.initials: WY
authors.lastname: Hung
authors.affiliation: Division of Pulmonary Medicine, Departments of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
authors.forename: M-C
authors.initials: MC
authors.lastname: Yu
authors.affiliation: School of Respiratory Therapy, College of Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Y-C
authors.initials: YC
authors.lastname: Chiang
authors.affiliation: Division of Pulmonary Medicine, Departments of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
authors.forename: J-H
authors.initials: JH
authors.lastname: Chang
authors.affiliation: Division of Pulmonary Medicine, Departments of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
authors.forename: C-Y
authors.initials: CY
authors.lastname: Chiang
authors.affiliation: Department of Pharmacy, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
authors.forename: C-C
authors.initials: CC
authors.lastname: Chang
authors.affiliation: Division of Pulmonary Medicine, Departments of Internal Medicine, Taipei Medical University Hospital, Taipei Medical University, Taipei, Taiwan.
authors.forename: H-C
authors.initials: HC
authors.lastname: Chuang
authors.affiliation: Division of Pulmonary Medicine, Departments of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
authors.forename: K-J
authors.initials: KJ
authors.lastname: Bai
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000995:Antitubercular Agents / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D003523:Cycloserine / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D004334:Drug Administration Schedule; D016903:Drug Monitoring; D005260:Female; D006801:Humans; D007408:Intestinal Absorption; D008297:Male; D008875:Middle Aged; D013624:Taiwan; D062606:Tertiary Care Centers; D016896:Treatment Outcome; D018088:Tuberculosis, Multidrug-Resistant / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy*; D055815:Young Adult
chemical_list: D000995:Antitubercular Agents; D003523:Cycloserine