title: Assay for screening for six antimalarial drugs and one metabolite using dried blood spot sampling, sequential extraction and ion-trap detection.
abstract: BACKGROUND
  More parasites are becoming resistant to antimalarial drugs, and in many areas a change in first-line drug treatment is necessary. The aim of the developed assay is to help determine drug use in these areas and also to be a complement to interviewing patients, which will increase reliability of surveys.
  
  
  RESULTS
  This assay detects quinine, mefloquine, sulfadoxine, pyrimethamine, lumefantrine, chloroquine and its metabolite desethylchloroquine in a 100-µl dried blood spot. Most of the drugs also have long half-lives that make them detectable at least 7 days after administration. The drugs are extracted from the dried blood spot with sequential extraction (due to the big differences in physicochemical properties), solid-phase extraction is used as sample clean-up and separation is performed with gradient-LC with MS ion-trap detection.
  
  
  CONCLUSIONS
  Detection limits (S/N > 5:1) at 50 ng/ml or better were achieved for all drugs except lumefantrine (200 ng/ml), and thus can be used to determine patient compliance. A major advantage of using the ion-trap MS it that it will be possible to go back into the data and look for other drugs as needed.
authors.affiliation: Dalarna University College, Borlange, Sweden. danielb@tropmedres.ac
authors.forename: Daniel
authors.initials: D
authors.lastname: Blessborn
authors.forename: Susanne
authors.initials: S
authors.lastname: Romsing
authors.forename: Yngve
authors.initials: Y
authors.lastname: Bergqvist
authors.forename: Niklas
authors.initials: N
authors.lastname: Lindegardh
mesh_terms: D000962:Antimalarials / Q000032:analysis* / Q000302:isolation & purification* / Q000378:metabolism; D001774:Blood Chemical Analysis / Q000379:methods*; D001800:Blood Specimen Collection / Q000379:methods*; D005591:Chemical Fractionation / Q000379:methods*; D002853:Chromatography, Liquid; D003890:Desiccation; D006801:Humans; D013058:Mass Spectrometry; D013997:Time Factors
chemical_list: D000962:Antimalarials