scholarly journals Carboxymefloquine, the Major Metabolite of the Antimalarial Drug Mefloquine, Induces Drug-Metabolizing Enzyme and Transporter Expression by Activation of Pregnane X Receptor

2014 ◽  
Vol 59 (1) ◽  
pp. 96-104 ◽  
Author(s):  
Rita Piedade ◽  
Stefanie Traub ◽  
Andreas Bitter ◽  
Andreas K. Nüssler ◽  
José P. Gil ◽  
...  
Keyword(s):  
Drug Interactions ◽  
Antimalarial Drug ◽  
Pregnane X Receptor ◽  
Antimalarial Drugs ◽  
Drug Metabolites ◽  
Protein Levels ◽  
Two Hybrid ◽  
Pharmacokinetic Drug

ABSTRACTMalaria patients are frequently coinfected with HIV and mycobacteria causing tuberculosis, which increases the use of coadministered drugs and thereby enhances the risk of pharmacokinetic drug-drug interactions. Activation of the pregnane X receptor (PXR) by xenobiotics, which include many drugs, induces drug metabolism and transport, thereby resulting in possible attenuation or loss of the therapeutic responses to the drugs being coadministered. While several artemisinin-type antimalarial drugs have been shown to activate PXR, data on nonartemisinin-type antimalarials are still missing. Therefore, this study aimed to elucidate the potential of nonartemisinin antimalarial drugs and drug metabolites to activate PXR. We screened 16 clinically used antimalarial drugs and six major drug metabolites for binding to PXR using the two-hybrid PXR ligand binding domain assembly assay; this identified carboxymefloquine, the major and pharmacologically inactive metabolite of the antimalarial drug mefloquine, as a potential PXR ligand. Two-hybrid PXR-coactivator and -corepressor interaction assays and PXR-dependent promoter reporter gene assays confirmed carboxymefloquine to be a novel PXR agonist which specifically activated the human receptor. In the PXR-expressing intestinal LS174T cells and in primary human hepatocytes, carboxymefloquine induced the expression of drug-metabolizing enzymes and transporters on the mRNA and protein levels. The crucial role of PXR for the carboxymefloquine-dependent induction of gene expression was confirmed by small interfering RNA (siRNA)-mediated knockdown of the receptor. Thus, the clinical use of mefloquine may result in pharmacokinetic drug-drug interactions by means of its metabolite carboxymefloquine. Whether thesein vitrofindings are ofin vivorelevance has to be addressed in future clinical drug-drug interaction studies.

scholarly journals Evaluation of antimalarial prescription pattern and susceptibility of Plasmodium falciparum isolates in Kaduna, Nigeria

2020 ◽  
Vol 13 (7) ◽  
pp. 3398-3410
Author(s):  
O. Ifeoluwa Akanni ◽  
J.O. Ehinmidu ◽  
R.O. Bolaji
Keyword(s):  
Plasmodium Falciparum ◽  
Combination Therapy ◽  
Antimalarial Drug ◽  
Drug Prescription ◽  
Artemisinin Combination Therapy ◽  
Therapy Resistance ◽  
Antimalarial Drugs ◽  
In Vitro Susceptibility

Nigeria carries the highest burden of malaria in terms of morbidity and mortality. This is compounded by continuous resistance of Plasmodium falciparum to antimalarial drugs. This study was designed to evaluate the profile of malaria patients’ antimalarial drug prescription and in vitro susceptibility of P. falciparum isolates to commonly prescribed antimalarial drugs in Kaduna, Nigeria. Three years’ records of patients antimalarial drug prescriptions were collated (2013 to 2015) and the in vitro antimalarial agent susceptibility was determined for 28 clinical isolates using WHO Mark III microtest. Artemisinin-based combination therapy (ACT) was the most prescribed antimalarial for the period under review (92.3-93.7%). Among the ACTs, Artemether-lumefantrine was most prescribed. Of the 28 P. falciparum isolates evaluated, 3 (10.71%) were resistant to chloroquine with a median IC50 of 4.82μM (4.60-8.14μM), while five (17.86%) were resistant to mefloquine with a median IC50 of 25μM (10.3-41μM), 7(25.00%) to artemether with a median IC50 of 2.69μM (2.09-8.77μM), 9 (32.14%) to artesunate-mefloquine combination with a median IC50 of 9.0μM (7.98-35μM) and to artesunate, 11(39.29%) were resistant with a median IC50 of 2.4μM (1.56-5.65μM). This result shows a decline in resistance of P. falciparum to chloroquine compared to period prior to artemisinin-combination therapy as well as reduced susceptibility to artesunate and artemether. Further in vitro and in vivo monitoring will be required to inform antimalarial drug policy change.Keywords: Antimalarial, Artemisinin-combination therapy, resistance, susceptibility, microtest.

scholarly journals Evaluation of Pharmacokinetic Drug–Drug Interactions: A Review of the Mechanisms, In Vitro and In Silico Approaches

Metabolites ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 75
Author(s):  
Yaru Peng ◽  
Zeneng Cheng ◽  
Feifan Xie
Keyword(s):  
Drug Interactions ◽  
In Silico ◽  
Drug Efficacy ◽  
Primary Concern ◽  
Factors Affecting ◽  
Pbpk Models ◽  
Drug Concentrations ◽  
Pharmacokinetic Drug

Pharmacokinetic drug–drug interactions (DDIs) occur when a drug alters the absorption, transport, distribution, metabolism or excretion of a co-administered agent. The occurrence of pharmacokinetic DDIs may result in the increase or the decrease of drug concentrations, which can significantly affect the drug efficacy and safety in patients. Enzyme-mediated DDIs are of primary concern, while the transporter-mediated DDIs are less understood but also important. In this review, we presented an overview of the different mechanisms leading to DDIs, the in vitro experimental tools for capturing the factors affecting DDIs, and in silico methods for quantitative predictions of DDIs. We also emphasized the power and strategy of physiologically based pharmacokinetic (PBPK) models for the assessment of DDIs, which can integrate relevant in vitro data to simulate potential drug interaction in vivo. Lastly, we pointed out the future directions and challenges for the evaluation of pharmacokinetic DDIs.

scholarly journals Utility of Alkylaminoquinolinyl Methanols as New Antimalarial Drugs

2006 ◽  
Vol 50 (12) ◽  
pp. 4132-4143 ◽  
Author(s):  
G. S. Dow ◽  
T. N. Heady ◽  
A. K. Bhattacharjee ◽  
D. Caridha ◽  
L. Gerena ◽  
...  
Keyword(s):  
Antimalarial Drug ◽  
Biological Properties ◽  
Antimalarial Drugs ◽  
Piperidine Ring ◽  
Side Chain ◽  
Commercial Development ◽  
Clinical Potential ◽  
Emergence Of Resistance

ABSTRACT Mefloquine has been one of the more valuable antimalarial drugs but has never reached its full clinical potential due to concerns about its neurologic side effects, its greater expense than that of other antimalarials, and the emergence of resistance. The commercial development of mefloquine superseded that of another quinolinyl methanol, WR030090, which was used as an experimental antimalarial drug by the U.S. Army in the 1970s. We evaluated a series of related 2-phenyl-substituted alkylaminoquinolinyl methanols (AAQMs) for their potential as mefloquine replacement drugs based on a series of appropriate in vitro and in vivo efficacy and toxicology screens and the theoretical cost of goods. Generally, the AAQMs were less neurotoxic and exhibited greater antimalarial potency, and they are potentially cheaper than mefloquine, but they showed poorer metabolic stability and pharmacokinetics and the potential for phototoxicity. These differences in physiochemical and biological properties are attributable to the “opening” of the piperidine ring of the 4-position side chain. Modification of the most promising compound, WR069878, by substitution of an appropriate N functionality at the 4 position, optimization of quinoline ring substituents at the 6 and 7 positions, and deconjugation of quinoline and phenyl ring systems is anticipated to yield a valuable new antimalarial drug.

scholarly journals Rifampicin Induces Gene, Protein, and Activity of P-Glycoprotein (ABCB1) in Human Precision-Cut Intestinal Slices

2021 ◽  
Vol 12 ◽  
Author(s):  
Ondrej Martinec ◽  
Carin Biel ◽  
Inge A. M. de Graaf ◽  
Martin Huliciak ◽  
Koert P. de Jong ◽  
...  
Keyword(s):  
Drug Interactions ◽  
Ex Vivo ◽  
Pregnane X Receptor ◽  
Functional Expression ◽  
Mrna Levels ◽  
Drug Bioavailability ◽  
Protein Levels ◽  
P Glycoprotein ◽  
Nuclear Factors

P-glycoprotein (ABCB1), an ATP-binding cassette efflux transporter, limits intestinal absorption of its substrates and is a common site of drug–drug interactions. Drug-mediated induction of intestinal ABCB1 is a clinically relevant phenomenon associated with significantly decreased drug bioavailability. Currently, there are no well-established human models for evaluating its induction, so drug regulatory authorities provide no recommendations for in vitro/ex vivo testing drugs’ ABCB1-inducing activity. Human precision-cut intestinal slices (hPCISs) contain cells in their natural environment and express physiological levels of nuclear factors required for ABCB1 induction. We found that hPCISs incubated in William’s Medium E for 48 h maintained intact morphology, ATP content, and ABCB1 efflux activity. Here, we asked whether rifampicin (a model ligand of pregnane X receptor, PXR), at 30 μM, induces functional expression of ABCB1 in hPCISs over 24- and 48-h incubation (the time to allow complete induction to occur). Rifampicin significantly increased gene expression, protein levels, and efflux activity of ABCB1. Moreover, we described dynamic changes in ABCB1 transcript levels in hPCISs over 48 h incubation. We also observed that peaks of induction are achieved among donors at different times, and the extent of ABCB1 gene induction is proportional to PXR mRNA levels in the intestine. In conclusion, we showed that hPCISs incubated in conditions comparable to those used for inhibition studies can be used to evaluate drugs’ ABCB1-inducing potency in the human intestine. Thus, hPCISs may be valuable experimental tools that can be prospectively used in complex experimental evaluation of drug–drug interactions.

Pharmacokinetic Drug-drug Interaction of Antibiotics Used in Sepsis Care in China

2020 ◽  
Vol 21 ◽  
Author(s):  
Xuan Yu ◽  
Zixuan Chu ◽  
Jian Li ◽  
Rongrong He ◽  
Yaya Wang ◽  
...  
Keyword(s):  
Drug Interaction ◽  
Drug Interactions ◽  
Penicillin G ◽  
Literature Mining ◽  
Human Pharmacokinetics ◽  
P450 Enzyme ◽  
Drug Drug Interaction ◽  
Pharmacokinetic Drug ◽  
Sepsis Care

Background: Many antibiotics have a high potential for having an interaction with drugs, as perpetrator and/or victim, in critically ill patients, and particularly in sepsis patients. Methods: The aim of this review is to summarize the pharmacokinetic drug-drug interaction (DDI) of 45 antibiotics commonly used in sepsis care in China. Literature mining was conducted to obtain human pharmacokinetics/dispositions of the antibiotics, their interactions with drug metabolizing enzymes or transporters, and their associated clinical drug interactions. Potential DDI is indicated by a DDI index > 0.1 for inhibition or a treated-cell/untreated-cell ratio of enzyme activity being > 2 for induction. Results: The literature-mined information on human pharmacokinetics of the identified antibiotics and their potential drug interactions is summarized. Conclusion: Antibiotic-perpetrated drug interactions, involving P450 enzyme inhibition, have been reported for four lipophilic antibacterials (ciprofloxacin, erythromycin, trimethoprim, and trimethoprim-sulfamethoxazole) and three lipophilic antifungals (fluconazole, itraconazole, and voriconazole). In addition, seven hydrophilic antibacterials (ceftriaxone, cefamandole, piperacillin, penicillin G, amikacin, metronidazole, and linezolid) inhibit drug transporters in vitro. Despite no reported clinical PK drug interactions with the transporters, caution is advised in the use of these antibacterials. Eight hydrophilic antibacterials (all β-lactams; meropenem, cefotaxime, cefazolin, piperacillin, ticarcillin, penicillin G, ampicillin, and flucloxacillin), are potential victims of drug interactions due to transporter inhibition. Rifampin is reported to perpetrate drug interactions by inducing CYP3A or inhibiting OATP1B; it is also reported to be a victim of drug interactions, due to the dual inhibition of CYP3A4 and OATP1B by indinavir. In addition, three antifungals (caspofungin, itraconazole, and voriconazole) are reported to be victims of drug interactions because of P450 enzyme induction. Reports for other antibiotics acting as victims in drug interactions are scarce.

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