Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0034065 (pulmonary embolism)
 14,979 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

(1) Sunitinib, a tyrosine kinase inhibitor, is marketed for the treatment of advanced-stage and metastatic renal carcinoma, and for second-line treatment of gastrointestinal stromal tumours. Sorafenib arrived on the market almost simultaneously for second-line treatment of kidney cancer. (2) In second-line treatment of kidney cancer, two non comparative trials showed an unusually high rate of at least partial tumour regression with sunitinib (25%, compared to only 2% with sorafenib). Head-to-head trials of the two drugs are lacking. Although indirect comparisons are notoriously unreliable, sunitinib appears to provide longer progression-free survival than sorafenib (about 9 months versus 5.5 months), although overall survival times are similar. (3) Preliminary results of a trial comparing sunitinib with interferon alfa as first-line treatments in 750 patients with kidney cancer show a 6-month event-free survival advantage in the sunitinib arm. The precise overall survival time has not yet been calculated. (4) In 312 patients with gastrointestinal stromal tumours in whom imatinib has failed, a double-blind placebo-controlled trial showed that sunitinib prolonged overall survival time, but potential biases undermine these results. (5) The adverse effect profile of sunitinib appears to be similar to those of imatinib and sorafenib, apart from more thyroid disorders. The principal adverse effects are cutaneous, gastrointestinal, cardiovascular and haematological disorders. Arterial hypertension, sometimes severe, occurred in 16% of patients treated with sunitinib. Other serious adverse events included tumour haemorrhage and pulmonary embolism. A risk of cardiac toxicity leading to heart failure cannot currently be ruled out. (6) Sunitinib is metabolised by cytochrome P450 isoenzyme CYP 3A4, increasing the likelihood of drug interactions. (7) These results support the use of sunitinib as second-line therapy for patients with gastrointestinal stromal tumours. Additional clinical evaluation is needed, however. In first-line treatment of kidney cancer, it is preferable to wait for detailed results of the ongoing trial, especially effects on survival time, before judging the possible advantages and disadvantages of sunitinib compared to interferon alfa. In second-line treatment, sorafenib is better-assessed than sunitinib and should therefore be preferred, pending a direct comparison of the two drugs.
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PMID:Sunitinib: new drug. For some gastrointestinal stromal tumours. 1772 33

We report the first genome-wide association study (GWAS) whose sample size (1,053 Swedish subjects) is sufficiently powered to detect genome-wide significance (p<1.5 x 10(-7)) for polymorphisms that modestly alter therapeutic warfarin dose. The anticoagulant drug warfarin is widely prescribed for reducing the risk of stroke, thrombosis, pulmonary embolism, and coronary malfunction. However, Caucasians vary widely (20-fold) in the dose needed for therapeutic anticoagulation, and hence prescribed doses may be too low (risking serious illness) or too high (risking severe bleeding). Prior work established that approximately 30% of the dose variance is explained by single nucleotide polymorphisms (SNPs) in the warfarin drug target VKORC1 and another approximately 12% by two non-synonymous SNPs (*2, *3) in the cytochrome P450 warfarin-metabolizing gene CYP2C9. We initially tested each of 325,997 GWAS SNPs for association with warfarin dose by univariate regression and found the strongest statistical signals (p<10(-78)) at SNPs clustering near VKORC1 and the second lowest p-values (p<10(-31)) emanating from CYP2C9. No other SNPs approached genome-wide significance. To enhance detection of weaker effects, we conducted multiple regression adjusting for known influences on warfarin dose (VKORC1, CYP2C9, age, gender) and identified a single SNP (rs2108622) with genome-wide significance (p = 8.3 x 10(-10)) that alters protein coding of the CYP4F2 gene. We confirmed this result in 588 additional Swedish patients (p<0.0029) and, during our investigation, a second group provided independent confirmation from a scan of warfarin-metabolizing genes. We also thoroughly investigated copy number variations, haplotypes, and imputed SNPs, but found no additional highly significant warfarin associations. We present power analysis of our GWAS that is generalizable to other studies, and conclude we had 80% power to detect genome-wide significance for common causative variants or markers explaining at least 1.5% of dose variance. These GWAS results provide further impetus for conducting large-scale trials assessing patient benefit from genotype-based forecasting of warfarin dose.
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PMID:A genome-wide association study confirms VKORC1, CYP2C9, and CYP4F2 as principal genetic determinants of warfarin dose. 1930 Apr 99

(1) The standard anticoagulant therapy for prevention of thrombosis after hip or knee replacement surgery is subcutaneous injection of a low-molecular-weight heparin, such as enoxaparin; (2) Rivaroxaban is an oral factor-Xa inhibitor anticoagulant approved for use in these indications in the European Union; (3) Four double-blind controlled trials in more than 12 000 patients undergoing hip or knee replacement surgery failed to show that rivaroxaban was any more effective than enoxaparin on relevant clinical outcomes; there was no reduction in mortality, nor in the incidence of pulmonary embolism and symptomatic deep venous thrombosis; (4) In the selected populations enrolled in these trials, the bleeding risk was similar in the rivaroxaban and enoxaparin groups. However, it is possible that very underweight or overweight patients have an increased bleeding risk with rivaroxaban; (5) More information is needed on the nephrotoxicity of rivaroxaban, and a risk of mitochondrial toxicity cannot be ruled out. Post-marketing studies also need to focus on the consequences of wound seepage, which is more frequent with rivaroxaban. (6) Rivaroxaban is metabolized by the cytochrome P450 isoenzyme CYP 3A4 and binds to P-glycoprotein, hence a high risk of pharmacokinetic interactions; (7) Rivaroxaban has the advantage of being an oral treatment that does not require laboratory monitoring. However, it seems best to monitor renal function. It should also be noted that there is no effective antidote if severe bleeding occurs; (8) In practice, for frail elderly patients, who are often polymedicated, it seems more prudent to continue using low-molecular-weight heparin, a drug with which we have more experience.
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PMID:Rivaroxaban: new drug. After hip or knee replacement surgery: LMWH is safer. 1974 67

Several newer anticoagulants are under clinical development. Recently two of them, Dabigatran etexilate/Pradaxa. and Rivaroxaban/Xarelto obtained marketing authorization in Europe and Canada for the prevention of thromboembolic events following major orthopedic surgery such as total hip and knee replacement. The results of Phase III clinical studies in thromboprophylaxis in major orthopedic surgery are highlighted and discussed in detail. Ongoing Phase II and III clinical trials assess their efficacy in the secondary prevention and treatment of deep vein thrombosis and pulmonary embolism, and in the long-term prevention of stroke in patients with non-valvular atrial fibrillation and in combination with aspirin and clopidogrel in patients with acute coronary syndromes. Many other small antithrombotic molecules including a new generation of low molecular weight heparins, are currently in different stages of clinical development. In addition to being administered orally, the newer anticoagulant agents have a more balanced benefit/risk ratio and wider therapeutic window. They have a rapid onset of action, a predictable anticoagulant effect that does not require routine laboratory monitoring. They have minor food and drug interactions, including those with cytochrome P450 and P.gp. They are highly specific and targeted to a single coagulation factor, and could carry similar or less hemorrhagic risks compared to the older anticoagulant agents. Finally, they may be used in a broader variety of patients, especially the medically ill patients with advanced cancer, and the elderly without any dosage adjustment, regardless of the patient age, gender, body weight, or in patients with mild renal impairment. Their use in the general world will hopefully confirm the promising results of clinical trials.
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PMID:Newer anticoagulants in 2009. 1983 70

Warfarin is a widely used anticoagulant in the treatment and prevention of thrombosis, in the treatment for chronic atrial fibrillation, mechanical valves, pulmonary embolism, and dilated cardiomyopathy. It is tasteless and colorless, was used as a poison, and is still marketed as a pesticide against rats and mice. Several long-acting warfarin derivatives-superwarfarin anticoagulants-such as brodifacoum, diphenadione, chlorophacinone, bromadiolone, are used as pesticides and can produce profound and prolonged anticoagulation. Several factors increase the risk of warfarin toxicity. However, polymorphisms in cytochrome P450 genes and drug interactions account for most of the risk for toxicity complications. Each person is unique in their degree of susceptibility to toxic agents. The toxicity interpretation and the health risk of most toxic substances are a subject of uncertainty. Genetically determined low metabolic capacity in an individual can dramatically alter the toxin and metabolite levels from those normally expected, which is crucial for drugs with a narrow therapeutic index, like warfarin. Personalized approaches in interpretation have the potential to remove some of the scientific uncertainties in toxicity cases.
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PMID:Warfarin toxicity and individual variability-clinical case. 2206 65

The standard anticoagulant for prevention of venous thromboembolism in patients undergoing hip or knee replacement surgery is a low-molecular-weight heparin (LMWH) such as subcutaneous enoxaparin. Apixaban is the second oral factor Xa inhibitor, after rivaroxaban, to be approved in the European Union for use in these two situations. Three double-blind randomised trials versus enoxaparin in a total of nearly 12 000 patients failed to show that apixaban was more effective in terms of relevant endpoints: mortality, and the incidence of pulmonary embolism and symptomatic deep vein thrombosis. The incidence of bleeding did not differ between the apixaban and enoxaparin groups under the conditions of these trials. Apixaban is mainly metabolised by cytochrome P450 isoenzymes CYP 3A4 and 3A5 and also binds to P-glycoprotein, resulting in a high potential for pharmacokinetic interactions. Renal failure is a risk factor for overdose. Pharmacodynamic interactions are also likely. There is no known antidote for apixaban. In practice, LMWH remains the standard treatment.
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PMID:Apixaban. After hip or knee replacement: LMWH remains the standard treatment. 2301 47

Venous thromboembolism includes deep vein thrombosis and pulmonary embolism and is a serious medical condition that requires anticoagulation as part of treatment. Currently, standard therapy consists of parenteral anticoagulation followed by a vitamin K antagonist (VKA). The pharmacokinetic and pharmacodynamic profiles of the direct oral anticoagulants (DOACs) differ from VKAs, which overcome some of the limitations of VKAs and have practical implications on their use in clinical situations. Dabigatran is a prodrug that undergoes primarily renal elimination and does not affect cytochrome P450 enzymes. Assays to quantify the degree of anticoagulation and the therapeutic level of DOAC are either unavailable for routine clinical use or require specific calibration. Routine monitoring of DOACs is not recommended at this time. Dabigatran, rivaroxaban, and apixaban are DOACs that have been studied for treatment of venous thromboembolism. Clinical trials comparing DOACs with standard therapy have shown them to be non-inferior for acute and extended therapy. Each DOAC has a unique benefit and harm profile that should be considered prior to use. The distinguishing characteristics of dabigatran include a requirement of parenteral anticoagulation prior to acute treatment, clinical trial results comparing it with a VKA for extended treatment, association with upper gastrointestinal adverse events, and increased risk of gastrointestinal bleed. Rivaroxaban is the only DOAC that has once-daily dosing while apixaban is the only DOAC that has lower risk of overall, major, and gastrointestinal bleeding compared with VKA. A common drawback of DOACs is the lack of an available reversal agent. Clinical trials of reversal agents are ongoing and one application for approval has been submitted to the US Food and Drug Administration. Selection of a DOAC for acute and extended therapy requires a shared decision-making approach that includes a comprehensive assessment of the benefits and harms of each individual DOAC.
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PMID:Differential benefit risk assessment of DOACs in the treatment of venous thromboembolism: focus on dabigatran. 2618 22

Coumarin derivatives such as warfarin and acenocoumarol are used in various disorders such as deep venous thrombosis, pulmonary embolism, atrial fibrillation and artificial heart valves. They have improved prognosis of patients with thromboembolic disease. An individual's response to coumarins depends on several factors. The non-genetic factors include age, gender, body mass index, diet and interacting drugs. Among the genetic factors, the cytochrome P450 system and vitamin K epoxide reductase complex subunit 1 play a key role in drug metabolism. This was a prospective hospital based study in which allele and genotypic frequencies of CYP2C9 gene polymorphisms; 430C>T and 1075A>C and VKORC1 gene polymorphisms; 1639G>A, 9041G>A and 6009C>T in 106 alleles of north Indian patients with valve replacement on acenocoumarol were determined and their effect on acenocoumarol dosing was studied. To the best of our knowledge, this is first report of VKORC1 9041G>A and 6009C>T gene polymorphisms and their effect on acenocoumarol dosing from north India. In 53 patients with valve replacement on acenocoumarol with stable INR, the allele frequency of CYP2C9*2 and CYP2C9*3 gene polymorphisms was 0.05 and 0.17 respectively and that of VKORC1 *2,*3 and *4 gene polymorphisms was 0.15, 0.72 and 0.11 respectively. The presence of CYP2C9*3 or VKORC1*2 gene polymorphism were associated with decrease in acenocoumarol dose requirements (p values 0.03 and 0.02 respectively).This study confirmed the association of lower mean weekly dosages of acenocoumarol in patients with CYP2C9*3 and VKORC1*2 gene polymorphisms. An unusually high frequency of 9041A polymorphism in VKORC1 was found in study population.
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PMID:High prevalence of VKORC1*3 (G9041A) genetic polymorphism in north Indians: A study on patients with cardiac disorders on acenocoumarol. 2678 25

In recent years, new direct-acting oral anticoagulants (DOACs) have been introduced into clinical practice that specifically inhibit either factor Ia or Xa. These drugs have, to a large extent, replaced warfarin for the treatment of venous thrombosis, pulmonary embolism, and non-valvular atrial fibrillation. They have potential advantages over warfarin in providing more stable anticoagulation and the lack of a need for regular venesection to monitor activity. They also have the promise of less drug and food interactions. All of these drugs are substrates for the permeability glycoprotein (P-gp) excretion system, and several are metabolised, in part, by cytochrome P450 (CYP) 3A4. This current article assesses the interactions that do or may occur with the DOACs, particularly with respect to the P-gp and CYP3A4 systems.
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PMID:Drug Interactions of Direct-Acting Oral Anticoagulants. 2743 52

Tuberculosis is a global health threat that affects millions of people every year, and treatment-limiting toxicity remains a considerable source of treatment failure. Recent reports have characterized the nature of hPXR-mediated hepatotoxicity and the systemic toxicity of antitubercular drugs. The antitubercular drug isoniazid plays a role in such pathologic states as acute intermittent porphyria, anemia, hepatotoxicity, hypercoagulable states (deep vein thrombosis, pulmonary embolism, or ischemic stroke), pellagra (vitamin B3 deficiency), peripheral neuropathy, and vitamin B6 deficiency. However, the mechanisms by which isoniazid administration leads to these states are unclear. To elucidate the mechanism of rifampicin- and isoniazid-induced liver and systemic injury, we performed tandem mass tag mass spectrometry-based proteomic screening of mPxr-/- and hPXR mice treated with combinations of rifampicin and isoniazid. Proteomic profiling analysis suggested that the hPXR liver proteome is affected by antitubercular therapy to disrupt [Fe-S] cluster assembly machinery, [2Fe-2S] cluster-containing proteins, cytochrome P450 enzymes, heme biosynthesis, homocysteine catabolism, oxidative stress responses, vitamin B3 metabolism, and vitamin B6 metabolism. These novel findings provide insight into the etiology of some of these processes and potential targets for subsequent investigations. Data are available via ProteomeXchange with identifier PXD019505.
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PMID:Toxicoproteomic Profiling of hPXR Transgenic Mice Treated with Rifampicin and Isoniazid. 3266 Jan 3


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