Simultaneous inhibition of Pgp by many CYP3A inhibitors contributes to human variation in the extent of drug-drug interactions. (nih.gov)
Conflicting drug-drug interaction (DDI) studies with the HIV protease inhibitors (PIs) suggest net induction or inhibition of intestinal or hepatic CYP3A. (aspetjournals.org)
The concomitant use of oxycodone and acetaminophen tablets with all cytochrome P450 3A4 inhibitors may result in an increase in oxycodone plasma concentrations, which could increase or prolong adverse reactions and may cause potentially fatal respiratory depression. (nih.gov)
Objectives: The objective of this study was to explore potential drug-drug/food interactions of ciprofloxacin and grapefruit juice, known hepatic cytochrome P450 (CYP) 1A2 inhibitors, on single-dose oral pharmacokinetics of riluzole, a substrate of CYP 1A2 enzymes. (researchgate.net)
Structure of cytochrome2
Here, the structure of cytochrome c(552) from P. denitrificans with the linker segment that attaches the globular domain to the membrane anchor is presented. (rcsb.org)
The results show that the tightly packed native structure of cytochrome c is disrupted at a rate of approximately 1.5 s-1 (independent of protein and lipid concentration), leading to the formation of a lipid-inserted denatured state (DL). (ox.ac.uk)
CYP3A44
Tadalafil is eliminated predominantly by hepatic metabolism, mainly by cytochrome P450 3A4 (CYP3A4). (theodora.com)
The presence in orange juice of compounds that specifically inhibit the P-glycoprotein (P-gp) drug efflux transporter, but not the cytochrome P450 (CYP) isozyme CYP3A4, was investigated. (aspetjournals.org)
Co-expression of cytochrome b5 (b5) is essential for CYP3A4 to manifest high activity toward fipronil. (cdc.gov)
The interactions of fipronil and other CYP3A4 substrates, such as testosterone and diazepam, were also investigated. (cdc.gov)
Superfamily of enzymes2
Cytochromes P450 (P450s or CYPs) are a superfamily of enzymes containing heme as a cofactor that mostly, but not exclusively, function as monooxygenases. (wikipedia.org)
This gene, CYP2A6, encodes a member of the cytochrome P450 superfamily of enzymes. (nih.gov)
Inhibition3
Many clinically important drug interactions occur due to inhibition of human liver cytochrome P450 3A (CYP3A) metabolism. (nih.gov)
Most drug interactions with ARV drugs are mediated through inhibition or induction of hepatic drug metabolism. (medscape.com)
In-vitro metabolic inhibition studies using rat and human livermicrosomes and intestinal absorption studies of riluzole in a rat everted gut-sac model were conducted to elucidate the mechanism of interaction. (researchgate.net)
Metabolism5
The potential for terbinafine interaction with other drugs is predicted to be insignificant with the exception that it may inhibit the metabolism of CYP2D6 substrates. (aspetjournals.org)
The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. (nih.gov)
Other pharmacodynamic and pharmacokinetic mechanisms of interactions (eg, alteration of gastric pH, UGT1A1 metabolism) can affect ARVs. (medscape.com)
In vitro metabolism of fipronil by human and rat cytochrome P450 and its interactions with testosterone and diazepam. (cdc.gov)
This study was designed to investigate the in vitro human metabolism of fipronil and to examine possible metabolic interactions that fipronil may have with other substrates. (cdc.gov)
Human liver2
Biotransformation pathways and the potential for drug-drug interactions of the orally active antifungal terbinafine were characterized using human livermicrosomes and recombinant human cytochrome P-450s (CYPs). (aspetjournals.org)
Fipronil was incubated with human livermicrosomes (HLM) and several recombinant cytochrome P450 (CYP) isoforms obtained from BD Biosciences. (cdc.gov)
Reductase3
Based on the nature of the electron transfer proteins, P450s can be classified into several groups: Microsomal P450 systems in which electrons are transferred from NADPH via cytochrome P450 reductase (variously CPR, POR, or CYPOR). (wikipedia.org)
Cytochrome b5 (cyb5) can also contribute reducing power to this system after being reduced by cytochrome b5 reductase (CYB5R). (wikipedia.org)
There are two major P450 classes in terms of the native RP systems, namely, the prokaryotic Class I P450 consisting of three stand-alone components (redoxin reductase/redoxin/P450) that are all cytosolically soluble proteins and the two-component eukaryotic Class II P450 comprised of P450 and cytochrome P450 reductase (CPR), both of which are membrane-bound proteins. (nature.com)
Enzymes2
The most common reaction catalyzed by cytochromes P450 is a monooxygenase reaction, e.g., insertion of one atom of oxygen into the aliphatic position of an organic substrate (RH), while the other oxygen atom is reduced to water: RH + O2 + NADPH + H+ → ROH + H2O + NADP+ Many hydroxylation reactions (insertion of hydroxyl groups) use CYP enzymes. (wikipedia.org)
Cytochrome P450 enzymes (P450s or CYPs) are a superfamily of heme-thiolate proteins widespread in all kingdoms of life 1 . (nature.com)
Substrates1
The drug efflux pump P-glycoprotein (Pgp) can be an additional locus contributing to these drug interactions because there is overlap in drugs that are substrates for both proteins. (nih.gov)
P450s1
The results provide insights into the domination for P450-redox partner interactions in modulating the catalytic activity of P450s. (nature.com)
Concomitant1
A detailed review of concomitant medications can help in creating a regimen that minimizes undesirable interactions. (medscape.com)
Membrane2
Our absorbance and fluorescence kinetic data, combined with a well-characterized mechanism for folding/unfolding of cytochrome c in solution, allow us to propose a kinetic mechanism for cytochrome c unfolding at the membrane surface. (ox.ac.uk)
Binding of native cytochrome c in water (NW) to DOPS vesicles is driven by the electrostatic interaction between positively charged residues in the protein and the negatively charged lipid headgroups on the membrane surface. (ox.ac.uk)
Mechanism1
Either increases toxicity of the other by unspecified interaction mechanism. (medscape.com)
Genes1
This gene is part of a large cluster of cytochrome P450 genes from the CYP2A, CYP2B and CYP2F subfamilies on chromosome 19q. (nih.gov)
Antiretroviral Therapy1
No identified drug interactions would preclude coadministration of tecovirimat with antiretroviral therapy (ART) for HIV infection. (cdc.gov)
Checker1
For more information regarding specific drug interactions, see the Medscape Drug Interaction Checker or the NIH Guidelines for the Use of Antiretroviral Agents in HIV-1-Infected Adults and Adolescents . (medscape.com)
Occur1
Thus, the interactions are evaluated in a qualitative manner to provide a sense of what influence the interactions may have when they do occur. (cdc.gov)
Drugs3
Pgp antagonism was defined by interactions of the drugs with four cell lines (LLC-PK1, L-MDR1, L-mdr1a, and L-mdr1b) using a microfluorometric calcein-AM assay and characterized for their inhibitor constant (K(i)) toward calcein-AM. The compounds were further defined for their ability to inhibit MDR1 by their effect on vinblastine accumulation into L-MDR1 cells. (nih.gov)
Transporters aid hepatic, renal, and biliary clearance of drugs and may be susceptible to drug interactions. (medscape.com)
In multivariate analysis, number of prescribed antimicrobials (odds ratio: 2.3001, 95% CI: 1.6237-3.2582), number of prescribed drugs (odds ratio: 1.2008, 95% CI: 1.0943-1.3177), and hospitalization in the university hospital (odds ratio: 1.7798, 95% CI: 1.0035-3.1564) were independent risk factors for developing drug interactions. (researchgate.net)
System1
The Micromedex® online drug reference system was used to control and describe the interactions. (researchgate.net)
Clarithromycin2
These data indicate that in addition to the liver, the intestine is a major site of the interaction between oral midazolam and clarithromycin. (nih.gov)
Quinolones, triazoles, metronidazole, linezolid, and clarithromycin accounted for 173 (25.7%) of 673 prescribed antimicrobials, but were responsible for 141 (92.1%) of 153 interactions. (researchgate.net)
Toxicity1
A weight-of-evidence approach is commonly used in these documents to evaluate the influence of interactions in the overall toxicity of the mixture. (cdc.gov)
Pathways1
Internal lipids mediate crosslinking to stabilize the domain-swapped iron-sulfur protein subunit, dielectric heterogeneity within intermonomer and intramonomer electron transfer pathways, and dimer stabilization through lipid-mediated intermonomer interactions. (rcsb.org)
Complex2
The dimeric photosynthetic cytochrome b6f complex, a 16-mer of eight distinct subunits and 26 transmembrane helices, catalyzes transmembrane proton-coupled electron transfer for energy storage. (rcsb.org)
The influence of drug transporters on drug-drug interactions is complex and requires further understanding. (medscape.com)
Results2
The results are summarized as follows: 1) Some drug interactions with Pgp were substrate- and/or assay-dependent. (nih.gov)
RESULTS: Potential drug-drug interactions with antimicrobials were 26.4% of all interactions. (researchgate.net)
Active1
The active site of cytochrome P450 contains a heme-iron center. (wikipedia.org)
Study1
The purpose of this study was to investigate the frequency and potential drug-drug interactions associated with antimicrobials among hospitalized patients. (researchgate.net)
Major1
Five (42%) of 12 contraindicated interactions and 61 (38%) of 159 major interactions were with antimicrobials. (researchgate.net)
Potential2
The purpose of an Interaction Profile is to evaluate data on the toxicology of the "whole" priority mixture (if available) and on the joint toxic action of the chemicals in the mixture in order to recommend approaches for the exposure-based assessment of the potential hazard to public health. (cdc.gov)
The potential for drug interactions should be assessed when any new drug (including over-the-counter agents) is added to an existing ARV regimen. (medscape.com)
Approximately1
Comparison with the expected rate of unfolding in solution (approximately 2 x 10(-3) s-1 at pH 5.0 in the absence of denaturant) suggests that the lipid environment dramatically accelerates the structural unfolding process of cytochrome c. (ox.ac.uk)
Specific1
DL) is limited by the rate of disruption of the hydrophobic core in MS. Equilibrium spectroscopic measurements by near-IR and Soret absorbance, fluorescence, and circular dichroism showed that DL has native-like helical secondary structure, but shows no evidence for specific tertiary interactions. (ox.ac.uk)