Coumarin Resistance

01/01/2007 - "We concluded that the mechanism of warfarin resistance in Tokyo roof rats is caused by increased clearance of warfarin."
10/01/2012 - "The objectives of this study were to quantify the effect of the VKORC1 D36Y variant (a marker of warfarin resistance previously described in 4% of Ashkenazi Jews) on warfarin maintenance doses and to examine how this variant affects the performance of the International Warfarin Pharmacogenetic Consortium (IWPC) dose prediction model. "
02/15/2008 - "In the separate study which was done in our laboratory on the gene that is possibly responsible for warfarin resistance we did not find any mutation in our patient with high warfarin concentration in their blood."
01/01/2018 - "Warfarin inhibition of KO to K reduction and carboxylation that requires full reduction were compared in wild-type VKORC1 or mutants (Y139H, Y139F) that cause warfarin resistance. "
11/01/2016 - "The mechanism of warfarin resistance in roof rats from Tokyo involved not only mutation of VKOR but also high clearance ability due to high levels of CYP2B, 2C and 3A expression possibly induced by warfarin."

05/01/2022 - "Warfarin resistance caused by vitamin K-rich broccoli was reported. "
12/01/2003 - "Titrating intravenous vitamin K with doses of 0.5 to 2.0 mg when INR > 5 is appropriate to reduce INR without causing warfarin resistance. "
01/01/1986 - "The parenteral administration of vitamin K proved to be the cause of the prolonged warfarin resistance."
01/01/1986 - "Acquired warfarin resistance has resulted from altered drug metabolism and excessive vitamin K. "
09/18/1982 - "Warfarin resistance caused by vitamin K in intestinal feeds."

04/01/2012 - "Evaluation of the warfarin-resistance polymorphism, VKORC1 Asp36Tyr, and its effect on dosage algorithms in a genetically heterogeneous anticoagulant clinic."
03/01/2000 - "Comorbid conditions, warfarin resistance, difficult venous access, and a potentially high bleeding risk are some of the factors that often complicate the prolonged course of anticoagulant therapy needed in this group. "
10/01/1998 - "Case studies in therapeutics: warfarin resistance and inefficacy in a man with recurrent thromboembolism, and anticoagulant-associated priapism."
03/01/2013 - "Educating patients, increasing warfarin dosage and switching to other anticoagulants would be effective for warfarin resistance."
11/01/2018 - "The alternate usage of first-generation anticoagulant rodenticides (FGARs) and second-generation anticoagulant rodenticides (SGARs) might represent an effective strategy against the development of warfarin resistance in Norway rats in China. "

07/01/2001 - "To study the biochemical mechanism of warfarin resistance, the mRNA expression levels of the major P450 forms in the warfarin-resistant and -susceptible roof rat liver following exposure to warfarin were quantified by competitive RT-PCR. "
07/01/2001 - "Suppression of CYP3A2 mRNA expression in the warfarin-resistant roof rat, Rattus rattus: possible involvement of cytochrome P450 in the warfarin resistance mechanism."

04/01/1985 - "This locates fz very close to Rw in linkage group I. The map position established for fz makes this allele particularly suitable for use in combination with p (pink-eyed dilution) for linkage tests in group I and as a genetic marker for the Rw locus in studies of warfarin resistance. "
04/01/1985 - "Fuzzy: a genetic marker for warfarin resistance in the Norway rat."

12/01/2014 - "This is the first study to evaluate warfarin resistance, APOE *ε4 and UGT1A1(TA) n genotypes in the Brazilian population, and the association of these two genotypes with warfarin dose required."

10/21/2013 - "In this study, we examined if C3435T polymorphism of MDR1 gene could be a factor of warfarin resistance. "

06/01/2011 - "Mutation analysis identified a Val66Met substitution in vitamin K epoxide reductase complex subunit 1 (VKORC1), consistent with severe warfarin resistance. "
06/01/2008 - "A vitamin K epoxide reductase complex subunit 1 mutation in an Irish patient with warfarin resistance."
05/29/1985 - "A comparison of warfarin resistance and liver microsomal vitamin K epoxide reductase activity in rats."
01/01/2016 - "A protein homology model of human vitamin K epoxide reductase, subunit 1 (VKORC1), was generated to elucidate the mechanism of warfarin resistance observed in a patient with the Val66Met mutation. "
10/10/2013 - "Assessment of warfarin resistance using the "classical" dithiothreitol-driven vitamin K 2,3-epoxide reductase (VKOR) assay has not reflected clinical resistance phenotypes for most mutations. "

03/01/2016 - "VKORC1 and CYP2C9 genotypes in Egyptian patients with warfarin resistance."
04/01/2012 - "We confirm the association between high-frequency SNPs, VKORC1 c.-1639G>A and CYP2C9 *2/*3 and warfarin sensitivity, and contribute additional evidence that the VKORC1 p.Asp36Tyr variant is recurrent and independently associated with warfarin resistance in our population. "
12/01/2011 - "An instructive case suggesting warfarin resistance which is independent on the regulation of the CYP2C9 and VKORC1 genotype."
01/01/2011 - "Six hundred and twenty-six individuals exhibiting partial or complete coumarin resistance were analyzed by VKORC1 gene sequencing and CYP2C9 haplotyping. "
05/01/2004 - "Warfarin resistance with poor CYP2C9 activity and CYP2C9*1*2 genotype."

02/05/2004 - "Mutations in VKORC1 cause warfarin resistance and multiple coagulation factor deficiency type 2."
10/01/2005 - "Mutations in VKORC1 result in two different phenotypes: warfarin resistance (WR) and multiple coagulation factor deficiency type 2 (VKCFD2). "
01/01/2021 - "Several tier 2 variants, including CYP2C9∗13, CYP2C19∗35, the CYP2C cluster variant (rs12777823), two variants in VKORC1 (rs61742245 and rs72547529) related to warfarin resistance, and two variants in GGCX (rs12714145 and rs11676382) related to clotting factor activation, were identified among these samples. "
05/01/2011 - "More on: endoplasmic reticulum loop VKORC1 substitutions cause warfarin resistance but do not diminish gamma-carboxylation of the vitamin K-dependent coagulation factors."
01/01/2008 - "Mutations in the VKORC1 gene causes generalized defective vitamin K-dependent clotting factors (VKCFD2) and warfarin resistance (WR). "

09/01/2017 - "Meticulous management of anticoagulation therapy is essential for a LVAD with warfarin resistance. "
09/01/2017 - "Anticoagulation therapy for a LVAD patient with acquired warfarin resistance."
01/01/2009 - "Genetic testing has been proposed as a useful tool for allowing prediction of the dose response during initial anticoagulation therapy, to assess variability in dose maintenance and to identify warfarin 'resistance'. "
10/01/1994 - "A female patient developed warfarin resistance after 2 years of satisfactory therapy. "
10/01/2015 - "RESULTS of the study may be applicable to individuals who are under warfarin therapy to avoid warfarin resistance or intolerance. "

06/01/1985 - "Warfarin resistance linked to enteral nutrition products."
10/01/2008 - "Warfarin resistance and enteral tube feeding: a vitamin K-independent interaction."
03/01/2008 - "Continuous enteral nutrition should be withheld for 1 hour before and after warfarin administration to prevent enteral nutrition-associated warfarin resistance."
03/01/1989 - "Previous reports of warfarin resistance implicated older enteral feeding products with a much higher vitamin K content. "
03/01/2008 - "Vitamin K-independent warfarin resistance after concurrent administration of warfarin and continuous enteral nutrition."

12/01/2008 - "To our knowledge, this is the first case report to demonstrate that patients undergoing a complete gastric resection followed by a Roux-en-Y gastric bypass procedure may display warfarin resistance. "
05/01/1998 - "The most probable explanation of warfarin resistance is the reduced surface area for drug absorption secondary to surgical removal of the patient's duodenum and gastrojejunostomy."

02/01/2005 - "Warfarin resistance in a patient with mechanical valve prosthesis."

11/01/2019 - "Necropsy results showed two cases of pannus formation around the inflow ostium because of warfarin resistance and hyperinflammation at the inflow cuff suture line. "