title: [Determination of isoniazide concentration in pleural effusion and its pleural permeability in patients with tuberculous pleurisy].
abstract: OBJECTIVE
  To establish a high-performance liquid chromatography (HPLC)-based method for determining isoniazide concentration in pleural effusion and plasma of patients with tuberculous pleurisy, and evaluate the permeability of isoniazide from blood into pleural effusion.
  
  
  METHODS
  We collected pleural effusion from 15 patients with tuberculous pleurisy 2 h after administration 300 mg isoniazide in the morning of day 1. Pleural effusion and plasma were obtained 2 h after isoniazide administration on day 3. Isoniazide concentration was measured using HPLC, and the penetration rate of isoniazide in pleural effusion was calculated.
  
  
  RESULTS
  Isoniazide concentration in the pleural effusion averaged 1.156∓1.190 µg/ml in the 15 patients at 2 h after isoniazide administration on day 1. On day 3, isoniazide concentration was 1.920∓1.294 µg/ml in the pleural effusion and 2.445∓1.463 µg/ml in the plasma, and the mean penetration rate of isoniazide from blood into the pleural effusion was 86.0%.
  
  
  CONCLUSIONS
  As isoniazide has a high penetration rate into the pleural effusion in most patients, continuous oral administration of isoniazid has been sufficient to achieve an effective treatment concentration, and intrapleural injection of isoniazide may seem unnecessary for non-drug-resistant tuberculosis pleurisy.
authors.affiliation: Department of Pharmacy, Nanfang Hospitial, Southern Medical University, Guangzhou, China. l_yuan12@yahoo.com.cn
authors.forename: Yuan
authors.initials: Y
authors.lastname: Liu
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhang
authors.forename: Junfeng
authors.initials: J
authors.lastname: Zhang
authors.forename: Guohua
authors.initials: G
authors.lastname: Huang
authors.forename: Shunfang
authors.initials: S
authors.lastname: Zhu
authors.forename: Sijia
authors.initials: S
authors.lastname: Liu
authors.forename: Guofeng
authors.initials: G
authors.lastname: Li
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005260:Female; D006801:Humans; D007538:Isoniazid / Q000493:pharmacokinetics*; D008297:Male; D008875:Middle Aged; D010539:Permeability; D010994:Pleura / Q000378:metabolism*; D010996:Pleural Effusion / Q000378:metabolism*; D014396:Tuberculosis, Pleural / Q000378:metabolism*; D055815:Young Adult
chemical_list: D007538:Isoniazid