title: Quantification of co-trimoxazole in serum and plasma using MS/MS.
abstract: BACKGROUND
  Co-trimoxazole is frequently used in the prophylaxis and treatment of Pneumocystis carinii pneumonia. High plasma concentrations of sulfamethoxazole or trimethoprim are correlated with toxicity. There is, however, a large variation in PK observed which can lead to underexposure or toxicity.
  
  
  RESULTS
  We developed a novel LC-MS/MS method to analyze the components of co-trimoxazole, trimethoprim and sulfamethoxazole and its metabolite sulfamethoxazole-N-acetyl. This new method is expeditious due to its limited sample preprocessing and a relatively short run-time of only 3 min.
  
  
  CONCLUSIONS
  This new method met the US FDA requirements on linearity, selectivity, precision, accuracy, matrix effects, recovery and stability and is suitable for routine analysis and future prospective studies.
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Clinical Pharmacy & Pharmacology, Groningen, The Netherlands.
authors.forename: Jacob A
authors.initials: JA
authors.lastname: Dijkstra
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Clinical Pharmacy & Pharmacology, Groningen, The Netherlands.
authors.forename: Noor Si
authors.initials: NS
authors.lastname: Alsaad
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Clinical Pharmacy & Pharmacology, Groningen, The Netherlands.
authors.forename: Kai van
authors.initials: Kv
authors.lastname: Hateren
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Clinical Pharmacy & Pharmacology, Groningen, The Netherlands.
authors.forename: Ben
authors.initials: B
authors.lastname: Greijdanus
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Clinical Pharmacy & Pharmacology, Groningen, The Netherlands.|University of Groningen, Department of Pharmacy, Division of Pharmacokinetics, Toxicology & Targeting, Groningen, The Netherlands.
authors.forename: Daan J
authors.initials: DJ
authors.lastname: Touw
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Clinical Pharmacy & Pharmacology, Groningen, The Netherlands.
authors.forename: Jan-Willem C
authors.initials: JW
authors.lastname: Alffenaar
mesh_terms: D000890:Anti-Infective Agents / Q000097:blood*; D006801:Humans; D010949:Plasma / Q000378:metabolism*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000097:blood*
chemical_list: D000890:Anti-Infective Agents; D015662:Trimethoprim, Sulfamethoxazole Drug Combination