title: Oral absorption of trimethoprim-sulfamethoxazole in patients with AIDS.
abstract: OBJECTIVE
  To determine the bioavailability of trimethoprim-sulfamethoxazole (TMP-SMX) in patients infected with the human immunodeficiency virus (HIV).
  
  
  METHODS
  Open-label, randomized, two-way crossover trial.
  
  
  METHODS
  Outpatient clinical research center affiliated with a community-based teaching hospital.
  
  
  METHODS
  Ten individuals diagnosed with the acquired immunodeficiency syndrome (AIDS) with CD4+ counts less than 200 cells/mm3, receiving TMP-SMX one double-strength tablet 3 times/week as prophylaxis for Pneumocystis carinii pneumonia (PCP), and without documented gastroenteropathy or diarrhea agreed to participate in the trial. One patient withdrew from the study secondary to development of symptomatic PCP. Data were available for analysis from the remaining nine subjects.
  
  
  METHODS
  Participants received TMP 160 mg and SMX 800 mg orally or intravenously during two study periods. Following dose administration, blood samples were collected at predetermined time points over 36 hours.
  
  
  RESULTS
  Analysis of TMP-SMX pharmacokinetic parameters (half-life, total body clearance, area under the serum concentration versus time curve, and peak concentration) failed to reveal any significant differences between intravenous and oral preparations. The calculated bioavailabilities of oral TMP and SMX (mean +/- SD) were 102.7% +/- 19.8% and 109.4% +/- 19.4%, respectively.
  
  
  CONCLUSIONS
  The absorption of TMP-SMX is not adversely affected by HIV infection in the absence of HIV-induced gastroenteropathy or diarrhea.
authors.affiliation: College of Pharmacy, University of Iowa, Iowa City 52242-1112, USA. michael-klepser@UIOWA.edu
authors.forename: M E
authors.initials: ME
authors.lastname: Klepser
authors.forename: Z
authors.initials: Z
authors.lastname: Zhu
authors.forename: D P
authors.initials: DP
authors.lastname: Nicolau
authors.forename: M A
authors.initials: MA
authors.lastname: Banevicius
authors.forename: P P
authors.initials: PP
authors.lastname: Belliveau
authors.forename: J W
authors.initials: JW
authors.lastname: Ross
authors.forename: L
authors.initials: L
authors.lastname: Broisman
authors.forename: R
authors.initials: R
authors.lastname: Quintiliani
authors.forename: C H
authors.initials: CH
authors.lastname: Nightingale
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000150:complications*; D000284:Administration, Oral; D000328:Adult; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D001682:Biological Availability; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D011020:Pneumonia, Pneumocystis / Q000517:prevention & control; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D000890:Anti-Infective Agents; D015662:Trimethoprim, Sulfamethoxazole Drug Combination