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Johannesen L, Vicente J, Mason JW, Erato C, Sanabria C, Waite-Labott K, Hong M, Lin J, Guo P, Mutlib A, Wang J, Crumb WJ, Blinova K, Chan D, Stohlman J, Florian J, Ugander M, Stockbridge N, Strauss DG. Late sodium current block for drug-induced long QT syndrome: Results from a prospective clinical trial. Clin Pharmacol Ther 2015; 99:214-23. [PMID: 26259627 DOI: 10.1002/cpt.205] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 08/05/2015] [Indexed: 12/19/2022]
Abstract
Drug-induced long QT syndrome has resulted in many drugs being withdrawn from the market. At the same time, the current regulatory paradigm for screening new drugs causing long QT syndrome is preventing drugs from reaching the market, sometimes inappropriately. In this study, we report the results of a first-of-a-kind clinical trial studying late sodium (mexiletine and lidocaine) and calcium (diltiazem) current blocking drugs to counteract the effects of hERG potassium channel blocking drugs (dofetilide and moxifloxacin). We demonstrate that both mexiletine and lidocaine substantially reduce heart-rate corrected QT (QTc) prolongation from dofetilide by 20 ms. Furthermore, all QTc shortening occurs in the heart-rate corrected J-Tpeak (J-Tpeak c) interval, the biomarker we identified as a sign of late sodium current block. This clinical trial demonstrates that late sodium blocking drugs can substantially reduce QTc prolongation from hERG potassium channel block and assessment of J-Tpeak c may add value beyond only assessing QTc.
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Affiliation(s)
- L Johannesen
- Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, Maryland, USA.,Department of Clinical Physiology, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden
| | - J Vicente
- Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, Maryland, USA.,Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, USA.,BSICoS Group, Aragón Institute for Engineering Research (I3A), IIS Aragón, University of Zaragoza, Zaragoza, Spain
| | - J W Mason
- Spaulding Clinical, West Bend, Wisconsin, USA.,University of Utah, Salt Lake City, Utah, USA
| | - C Erato
- Spaulding Clinical, West Bend, Wisconsin, USA
| | - C Sanabria
- Spaulding Clinical, West Bend, Wisconsin, USA
| | | | - M Hong
- Frontage Laboratories, Exton, Pennsylvania, USA
| | - J Lin
- Frontage Laboratories, Exton, Pennsylvania, USA
| | - P Guo
- Frontage Laboratories, Exton, Pennsylvania, USA
| | - A Mutlib
- Frontage Laboratories, Exton, Pennsylvania, USA
| | - J Wang
- Frontage Laboratories, Exton, Pennsylvania, USA
| | - W J Crumb
- Zenas Technologies, Metairie, Louisiana, USA
| | - K Blinova
- Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - D Chan
- Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - J Stohlman
- Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - J Florian
- Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - M Ugander
- Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, Maryland, USA.,Department of Clinical Physiology, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden
| | - N Stockbridge
- Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - D G Strauss
- Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, Maryland, USA.,Department of Clinical Physiology, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden
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Shi G, Lloyd TL, Sy SKB, Jiao Q, Wernicki A, Mutlib A, Emm TA, Unger SE, Pieniaszek HJ. Simultaneous quantification of seven active metabolites of roxifiban in human plasma by LC/MS/MS in the presence of an interfering displacer at millimolar concentrations. J Pharm Biomed Anal 2003; 31:937-51. [PMID: 12684106 DOI: 10.1016/s0731-7085(02)00675-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Roxifiban (DMP 754) is a glycoprotein (GP) IIb/IIIa antagonist. Following oral administration to humans, roxifiban is metabolized to its primary active zwitterionic form, XV459, and several minor, active, hydrolyzed and hydroxylated metabolites, namely, M1a (DPC-AD3508), M1b (DPC-AD6128), M2 (SW156), M3 (DPC-AG2185), M8a (DPC-AF5814), and M8b (DPC-AF5818). Quantification of these metabolites in humans was not workable with a previous analytical method due to ion suppression of at least four of the analytes by a competitive displacer, DMP 728. This compound, which is another GP IIb/IIIa antagonist with very high affinity for the platelet receptor, was added to harvested blood samples in millimolar quantity to liberate XV459 from the GP IIb/IIIa receptor. An automated ion exchange solid phase extraction (IX-SPE) procedure was developed to selectively extract the seven metabolites of roxifiban and its deuterated internal standard while specifically excluding DMP 728. Among the six hydroxylation metabolites, there were two pairs of epimeric diastereomers (M1a/M1b and M8a/M8b) and one pair of geometric isomers (M2/M3), corresponding to three critical chromatographic pairs that needed to be base-line resolved because of the lack of specificity of MS/MS detection for these isomers. A new LC/MS/MS assay was developed to simultaneously quantify the seven metabolites in human plasma. The assay method was validated under GLP conditions over the concentration range of 0.5 to 80 nM for each of the analytes and successfully applied to assaying approximately 500 plasma samples from clinical trials.
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Affiliation(s)
- G Shi
- Bristol-Myers Squibb Company, Drug Metabolism and Pharmacokinetics, Stine-Haskell Research Center, 1090 Elkton Road, Newark, DE 19711, USA.
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Mutlib A, Shockcor J, Chen SY, Espina R, Lin J, Graciani N, Prakash S, Gan LS. Formation of unusual glutamate conjugates of 1-[3-(aminomethyl)phenyl]-N-[3-fluoro-2'-(methylsulfonyl)-[1,1'-biphenyl]-4-yl]-3-(trifluoromethyl)-1H-pyrazole-5-carboxamide (DPC 423) and its analogs: the role of gamma-glutamyltranspeptidase in the biotransformation of benzylamines. Drug Metab Dispos 2001; 29:1296-306. [PMID: 11560873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
The role of gamma-glutamyltranspeptidase (GGT) in transferring glutamate from endogenous glutathione (GSH) to the benzylamine moiety of a compound, such as 1-[3-(aminomethyl)phenyl]-N-[3-fluoro-2'-(methylsulfonyl)-[1,1'-biphenyl]-4-yl]-3-(trifluoromethyl)-1H-pyrazole-5-carboxamide (DPC 423), is described. Studies were performed with structurally related analogs of DPC 423 to demonstrate that this type of reaction was common to compounds possessing a benzylamine group. Synthesizing appropriate standards and confirming by liquid chromatography (LC)/mass spectroscopy and LC/NMR made unambiguous assignments of the structures of glutamate conjugates of DPC 423. The use of stable isotope-labeled GSH for metabolism studies has not been described before. In the present study, we report the novel use of deuterated GSH in conjunction with mass spectral analysis to demonstrate the glutamate transfer to the benzylamines in the presence of GGT. To further demonstrate that the alpha protons on the benzylamines and glutamate (as part of glutathione) were unaffected during the transpeptidation, these protons were replaced with deuterium. Acivicin (AT-125), a potent and selective inhibitor of GGT, was used to abolish the formation of the glutamate conjugates of DPC 423 in vitro and in vivo. This provided further evidence of the role of GGT in forming the glutamate conjugates of benzylamines. This study demonstrated conclusively that GGT was responsible for mediating the transfer of glutamic acid from GSH to the benzylamine moiety of a series of structurally related compounds.
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Affiliation(s)
- A Mutlib
- Drug Metabolism and Pharmacokinetics Section, DuPont Pharmaceuticals Company, Stine-Haskell Research Center, Newark, Delaware 19714, USA.
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Mutlib A, Chen H, Shockcor J, Espina R, Chen S, Cao K, Du A, Nemeth G, Prakash S, Gan LS. Characterization of novel glutathione adducts of a non-nucleoside reverse transcriptase inhibitor, (S)-6-chloro-4-(cyclopropylethynyl)-4-(trifluoromethyl)-3, 4-dihydro-2(1H)-quinazolinone (DPC 961), in rats. Possible formation of an oxirene metabolic intermediate from a disubstituted alkyne. Chem Res Toxicol 2000; 13:775-84. [PMID: 10956066 DOI: 10.1021/tx000029g] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The postulated formation of oxirene-derived metabolites from rats treated with a disubstituted alkyne, (S)-6-chloro-4-(cyclopropylethynyl)-4-(trifluoromethyl)-3, 4-dihydro-2(1H)-quinazolinone (DPC 961), is described. The reactivity of this postulated oxirene intermediate led to the formation of novel glutathione adducts whose structures were confirmed by LC/MS and by two-dimensional NMR experiments. These metabolites were either excreted in rat bile or degraded to mercapturic acid conjugates and eliminated in urine. To demonstrate the oxidation of the triple bond, an analogue of DPC 961 was synthesized, whereby the two carbons of the alkyne moiety were replaced with (13)C stable isotope labels. Rats were orally administered [(13)C]DPC 961 and glutathione adducts isolated from bile. The presence of an oxygen atom on one of the (13)C labels of the alkyne was demonstrated unequivocally by NMR experiments. Administration of (14)C-labeled DPC 961 showed that biliary elimination was the major route of excretion with the 8-OH glucuronide conjugate (M1) accounting for greater than 90% of the eliminated radioactivity. On the basis of radiochemical profiling, the glutathione-derived metabolites were minor in comparison to the glucuronide conjugate. Studies with cDNA-expressed rat enzymes, polyclonal antibodies, and chemical inhibitors pointed to the involvement of P450 3A1 and P450 1A2 in the formation of the postulated oxirene intermediate. The proposed mechanism shown in Scheme 1 begins with P450-catalyzed formation of an oxirene, rearrangement to a reactive cyclobutenyl ketone, and a 1,4-Michael addition with endogenous glutathione to produce two isomeric adducts, GS-1 and GS-2. The glutathione adducts were subsequently catabolized via the mercapturic acid pathway to cysteinylglycine, cysteine, and N-acetylcysteine adducts. The transient existence of the alpha,beta-unsaturated cyclobutenyl ketone was demonstrated by incubating the glutathione adduct in the presence of N-acetylcysteine and monitoring the formation of N-acetylcysteine adducts by LC/MS. Epimerization of GS-1 to GS-2 was also observed when N-acetylcysteine was omitted from the incubation.
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Affiliation(s)
- A Mutlib
- Drug Metabolism and Pharmacokinetics Section and Department of Chemical and Physical Sciences, DuPont Pharmaceuticals Company, Stine-Haskell Research Center, P.O. Box 30, Newark, Delaware 19714, USA.
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Tonn GR, Mutlib A, Abbott FS, Rurak DW, Axelson JE. Simultaneous analysis of diphenhydramine and a stable isotope analog (2H10)diphenhydramine using capillary gas chromatography with mass selective detection in biological fluids from chronically instrumented pregnant ewes. Biol Mass Spectrom 1993; 22:633-42. [PMID: 8251550 DOI: 10.1002/bms.1200221103] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
This report describes both the synthesis of a stable isotope analog of the H1 receptor antagonist diphenhydramine (DPHM), and the simultaneous quantitation of DPHM and a deuterated stable isotope analog of DPHM, viz. (2H10)DPHM in biological fluids from the chronically instrumented pregnant ewe. (2H10)DPHM was synthesized and purified, and both its structure and purity were verified. Biological samples were prepared for analysis using liquid-liquid extraction prior to capillary gas chromatography/mass spectrometry. The method employed electron impact ionization with selective ion monitoring of ions with m/z 165 for DPHM and m/z 173 for (2H10)DPHM. The minimal quantifiable concentration of DPHM and (2H10)DPHM from a 1.0 ml sample was 2.0 ng ml-1 in fetal and maternal plasma, fetal tracheal fluid and amniotic fluid. The method was validated from 2.0 ng ml-1 to 200.0 ng ml-1 for both DPHM and (2H10)DPHM in plasma, fetal tracheal fluid and amniotic fluid. Differences in the disposition between DPHM and (2H10)DPHM were not apparent during a control experiment in which both labeled and unlabeled DPHM were administered to a chronically instrumented fetal lamb. This method provides the required sensitivity and selectivity for the simultaneous quantitation of unlabeled and labeled DPHM during pharmacokinetic experiments conducted in near-term pregnant sheep.
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Affiliation(s)
- G R Tonn
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada
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