title: Simultaneous quantification of mefloquine (+)- and (-)-enantiomers and the carboxy metabolite in dried blood spots by liquid chromatography/tandem mass spectrometry.
abstract: Mefloquine (MQ), a racemic mixture of (+)-(11S,12R)- and (-)-(11R,12S)-MQ, has been used for treatment and prophylaxis of malaria for almost 30 years. MQ is metabolized by the cytochrome P450 3A subfamily to 4-carboxymefloquine (CMQ), which shows no antimalarial activity in vitro. Highly stereospecific pharmacokinetics of MQ have been reported, although with contradictory results. This might be due to incorrect assignment of the absolute configuration as shown only recently. Gastrointestinal as well as neuropsychiatric adverse events were described after prophylaxis and treatment with MQ. Data are indicating that the tolerability of the enantiomers may vary considerably. An involvement of the main metabolite CMQ in the development of neuropsychiatric adverse events has also been supposed. Due to these inconsistent results we established a novel liquid chromatography/tandem mass spectrometry (LC-MS/MS) method for the simultaneous quantification of MQ enantiomers and the metabolite CMQ to investigate the attribution of efficacy and adverse effects to the single enantiomers as well as the main metabolite. Separation of the MQ enantiomers was achieved on a quinidine-based zwitterionic chiral stationary phase column, CHIRALPAK(®) ZWIX(-) (3.0×150mm, 3μm) in an isocratic run using a pre-mixed eluent consisting of methanol/acetonitrile/water (49:49:2 v/v) with 25mM formic acid and 12.5mM ammonium formate. We used stable isotope-labelled analogues as internal standards. The method was validated according to the FDA guidelines. With a linear calibration range from 5 to 2000nM for the MQ enantiomers and from 13 to 2600nM for CMQ respectively, the method was successfully applied to dried blood spot (DBS) samples from patients under prophylactic MQ treatment. The method was also applicable for plasma samples.
authors: Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology and University of Tuebingen, Auerbachstrasse 112, 70376 Stuttgart, Germany.
authors: Mirjam C K
authors: MC
authors: Geditz
authors: Department of Analytical Chemistry, University of Vienna, Währinger Straße 38, 1090 Vienna, Austria.
authors: Wolfgang
authors: W
authors: Lindner
authors: Institute of Pharmaceutical Science, University of Tuebingen, Auf der Morgenstelle 8, 72076 Tuebingen, Germany.
authors: Michael
authors: M
authors: Lämmerhofer
authors: Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology and University of Tuebingen, Auerbachstrasse 112, 70376 Stuttgart, Germany.
authors: Georg
authors: G
authors: Heinkele
authors: Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology and University of Tuebingen, Auerbachstrasse 112, 70376 Stuttgart, Germany.
authors: Reinhold
authors: R
authors: Kerb
authors: Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria; Institut für Tropenmedizin, Universitaet Tuebingen, Wilhelmstrasse 27, 72074 Tuebingen, Germany.
authors: Michael
authors: M
authors: Ramharter
authors: Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology and University of Tuebingen, Auerbachstrasse 112, 70376 Stuttgart, Germany; Department of Clinical Pharmacology, University Hospital, Auf der Morgenstelle 8, 72076 Tuebingen, Germany.
authors: Matthias
authors: M
authors: Schwab
authors: Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology and University of Tuebingen, Auerbachstrasse 112, 70376 Stuttgart, Germany. Electronic address: ute.hofmann@ikp-stuttgart.de.
authors: Ute
authors: U
authors: Hofmann
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D002138:Calibration; D002853:Chromatography, Liquid / Q000379:methods*; D059788:Dried Blood Spot Testing / Q000379:methods*; D005260:Female; D006801:Humans; D015767:Mefloquine / Q000737:chemistry*; D000432:Methanol / Q000737:chemistry; D011247:Pregnancy; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013237:Stereoisomerism; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014867:Water / Q000737:chemistry
chemical_list: D000097:Acetonitriles; D014867:Water; D015767:Mefloquine; D000432:Methanol; C032159:acetonitrile
keywords: Antimalarial drug; Carboxymefloquine; Chiral separation; Dried blood spots; LC–MS/MS; Mefloquineenantiomers