Effect of Stress on International Normalized Ratio during Warfarin Therapy

2002 ◽  
Vol 36 (4) ◽  
pp. 617-620 ◽  
Author(s):  
Toni L Hawk ◽  
Dawn E Havrda
Keyword(s):  
Physical Activity ◽  
Drug Interactions ◽  
Patient Compliance ◽  
Warfarin Therapy ◽  
International Normalized Ratio ◽  
Anticoagulation Clinic ◽  
Stressful Events ◽  
Stressful Event ◽  
Dietary Changes ◽  
Case Summary

OBJECTIVE: To discuss the effect of stress on the international normalized ratio (INR) when patients are taking warfarin. CASE SUMMARY: Two patients at a pharmacist-managed anticoagulation clinic who were stable with anticoagulation developed elevated INR values after a stressful event occurred. All other factors known to elevate the INR were unchanged; furthermore, the INR values returned to the prior level of control after resolution of the stressful events. DISCUSSION: Management of anticoagulation with warfarin requires the knowledge of factors that may alter an INR. Many of these factors, such as dietary changes, illnesses, drug interactions, patient compliance, and physical activity, have been described. In spite of this understanding, many patients continue to experience variability in their INR values, suggesting there are other factors that can alter the INR that have not been fully described. The cases presented here demonstrate that stressful events, physical or psychological, can elevate the INR. The mechanism for this occurrence is unknown, but may be related to decreased metabolism of warfarin during stress. CONCLUSIONS: When an unexplained INR value exists, a stressor should be evaluated as a potential cause.

A Review of Warfarin Dosing With Concurrent Acetaminophen Therapy

2013 ◽  
Vol 26 (5) ◽  
pp. 518-521 ◽  
Author(s):  
G. Michelle Pinson ◽  
Jennifer W. Beall ◽  
Jeffrey A. Kyle
Keyword(s):  
Drug Interaction ◽  
Drug Interactions ◽  
Warfarin Therapy ◽  
International Normalized Ratio ◽  
Over The Counter ◽  
Pain Medications ◽  
Concurrent Use ◽  
Prevention And Treatment ◽  
Drug Drug Interaction ◽  
Warfarin Dosing

Warfarin is frequently used for the prevention and treatment of thromboembolism, yet it is associated with numerous drug interactions. Regarding over-the-counter pain medications, the preferred analgesic for those patients who are taking warfarin is acetaminophen. There are, however, reports of elevation in the international normalized ratio (INR) in those patients taking concurrent warfarin and acetaminophen. For those practitioners who manage warfarin therapy, there is little guidance regarding management of the drug–drug interaction between warfarin and acetaminophen. This review seeks to evaluate the drug interaction between warfarin and acetaminophen and provides recommendations for concurrent use of these drugs.

Oral Vitamin K1: An Option To Reduce Warfarin'S Activity

1995 ◽  
Vol 29 (12) ◽  
pp. 1228-1232 ◽  
Author(s):  
Colleen C Harrell ◽  
Sandra S Kline
Keyword(s):  
At Risk ◽  
Vitamin K ◽  
Warfarin Therapy ◽  
Cost Effective ◽  
International Normalized Ratio ◽  
Extensive Literature ◽  
Oral Vitamin ◽  
Risk Of Bleeding ◽  
Case Summary ◽  
Patients At Risk

Objective: To report 6 patients taking oral vitamin K1 (phytonadione) to reduce warfarin's activity. Case Summary: Six patient cases are summarized in which oral vitamin K1 was used to reduce the international normalized ratio (INR) in patients at risk of bleeding. Discussion: The use of oral vitamin K1 to antagonize warfarin's effects is discussed, as well as the benefits of oral vitamin K1 administration and the disadvantages of parenteral vitamin K1 administration. In addition, an extensive literature review of the discovery and clinical development of warfarin and vitamin K1 is described. Conclusions: In patients receiving warfarin therapy who have an increased INR and are at risk of bleeding, oral vitamin K1 therapy may be safer, less painful, and more cost-effective than the traditional parenteral route of administration.

Levofloxacin and Warfarin Interaction

2002 ◽  
Vol 36 (10) ◽  
pp. 1554-1557 ◽  
Author(s):  
Cade B Jones ◽  
Susan E Fugate
Keyword(s):  
Binding Sites ◽  
Warfarin Therapy ◽  
Case Reports ◽  
Anticoagulation Therapy ◽  
Warfarin Dose ◽  
International Normalized Ratio ◽  
Minor Bleeding ◽  
Protein Binding Sites ◽  
Case Summary

OBJECTIVE: To report 4 cases of hypoprothrombotic response resulting from addition of levofloxacin therapy to chronic warfarin therapy and to review related literature to support or refute a warfarin—levofloxacin interaction. CASE SUMMARY: Four patients, 34–81 years old, were prescribed levofloxacin concomitantly with stable warfarin therapy. Three patients had a target international normalized ratio (INR) range of 2.0–3.0 and experienced an increase in INR to 3.5, 8.12, and 11.5 on days 11, 5, and 4 of a 10-day course of levofloxacin, respectively. The fourth patient experienced minor bleeding, with a slightly elevated INR on the second day of levofloxacin therapy that required up to a 19% warfarin dose reduction during levofloxacin treatment. DISCUSSION: An initial premarketing clinical trial concluded that levofloxacin had no effect on warfarin's pharmacokinetics and pharmacodynamic response. Two case reports have since documented an increase in INR in patients taking long-term warfarin on completion of levofloxacin therapy. Our case reports provide further evidence of a significant increase in INR observed during concomitant levofloxacin therapy. The proposed mechanism of this interaction is displacement of warfarin from protein binding sites, reduction in gut flora producing vitamin K, and decreased warfarin metabolism. CONCLUSIONS: Prolonged prothrombin response in patients undergoing chronic warfarin therapy has been well documented with many antibiotics, including fluoroquinolones. Recognition of newer antibiotics' effects on warfarin therapy is important to guide safe use and monitoring of anticoagulation therapy. Our case studies demonstrate significant elevations in INR values during and up to 1 day after levofloxacin therapy in patients undergoing stable warfarin therapy.

Possible Warfarin Interaction with Menthol Cough Drops

2005 ◽  
Vol 39 (2) ◽  
pp. 365-367 ◽  
Author(s):  
Paul J Kassebaum ◽  
Don L Shaw ◽  
Dave J Tomich
Keyword(s):  
Warfarin Therapy ◽  
Causality Assessment ◽  
White Male ◽  
Warfarin Dose ◽  
International Normalized Ratio ◽  
Warfarin Interaction ◽  
Case Summary ◽  
First Case ◽  
Patient Reported

OBJECTIVE: To report a case of possible interaction of menthol cough drops (Halls) with warfarin in a patient awaiting cardioversion. CASE SUMMARY: A 57-year-old white male awaiting cardioversion for atrial fibrillation was prescribed warfarin. His dosage was adjusted to 7 mg daily to provide stable international normalized ratio (INR) values of 2.28–2.68. Approximately one week later, his INR fell to 1.45. During a follow-up interview, the patient reported that he experienced a flu-like illness during the previous week and had been using menthol cough drops. No other potential causes for the decreased INR were found. Illness will most often elevate the INR; we therefore concluded that the cough drops were the likely cause of this reaction, and the warfarin dose was increased to 53 mg/wk. After discontinuing use of menthol cough drops, the warfarin dose was returned to the previous amount and the INR remained stabilized. DISCUSSION: An objective causality assessment suggests that the decreased INR was possibly related to the use of menthol cough drops during warfarin therapy. The active ingredient in these cough drops is menthol. Menthol has been shown to affect the pharmacokinetics of other drugs by inducing or inhibiting cytochrome P450 isoenzymes and slowing drug absorption. It is not clear whether these mechanisms played a role in this case. As of January 5, 2005 this is the first case report documenting an interaction between warfarin and cough drops containing menthol. CONCLUSIONS: This case documents a significant decrease in the INR following the use of menthol cough drops. Patients who are ill have several factors that can potentially affect their INR and should be monitored closely.

scholarly journals Maternal exposure to a high-magnitude earthquake during pregnancy influences pre-reading skills in early childhood

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Luis Federico Bátiz ◽  
Yasna K. Palmeiro-Silva ◽  
Gregory E. Rice ◽  
Lara J. Monteiro ◽  
Albert M. Galaburda ◽  
...  
Keyword(s):  
Reading Skills ◽  
First Trimester ◽  
Maternal Exposure ◽  
Stressful Events ◽  
Stressful Event ◽  
Prenatally Exposed ◽  
Alphabet Knowledge ◽  
Print Knowledge ◽  
Effective Strategies ◽  
High Magnitude

AbstractExposure to an adverse prenatal environment can influence fetal development and result in long-lasting changes in the offspring. However, the association between maternal exposure to stressful events during pregnancy and the achievement of pre-reading skills in the offspring is unknown. Here we examined the association between prenatal exposure to the Chilean high-magnitude earthquake that occurred on February 27th, 2010 and the development of early reading precursors skills (listening comprehension, print knowledge, alphabet knowledge, vocabulary, and phonological awareness) in children at kindergarten age. This multilevel retrospective cohort study including 3280 children, of whom 2415 were unexposed and 865 were prenatally exposed to the earthquake shows substantial evidence that maternal exposure to an unambiguously stressful event resulted in impaired pre-reading skills and that a higher detrimental effect was observed in those children who had been exposed to the earthquake during the first trimester of gestation. In addition, females were more significantly affected by the exposure to the earthquake than their male peers in alphabet knowledge; contrarily, males were more affected than females in print knowledge skills. These findings suggest that early intervention programs for pregnant women and/or children exposed to prenatal stress may be effective strategies to overcome impaired pre-reading skills in children.

International Normalized Ratio values in group versus individual appointments in a pharmacist-managed anticoagulation clinic

2009 ◽  
Vol 66 (13) ◽  
pp. 1218-1223 ◽  
Author(s):  
Brooke L. Griffin ◽  
Jill S. Burkiewicz ◽  
Laura R. Peppers ◽  
Terri L. Warholak
Keyword(s):  
Group Versus ◽  
International Normalized Ratio ◽  
Anticoagulation Clinic

scholarly journals Concurrent Spontaneous Sublingual and Intramural Small Bowel Hematoma due to Warfarin Use

2015 ◽  
Vol 2015 ◽  
pp. 1-3 ◽  
Author(s):  
Gül Pamukçu Günaydın ◽  
Hatice Duygu Çiftçi Sivri ◽  
Serkan Sivri ◽  
Yavuz Otal ◽  
Ayhan Özhasenekler ◽  
...  
Keyword(s):  
Emergency Department ◽  
Small Bowel ◽  
Warfarin Therapy ◽  
International Normalized Ratio ◽  
Fresh Frozen Plasma ◽  
Close Monitoring ◽  
Observation Unit ◽  
Fresh Frozen ◽  
Tomography Scan ◽  
Frozen Plasma

Introduction. We present a case of concurrent spontaneous sublingual and intramural small bowel hematoma due to warfarin anticoagulation.Case. A 71-year-old man presented to the emergency department complaining of a swollen, painful tongue. He was on warfarin therapy. Physical examination revealed sublingual hematoma. His international normalized ratio was 11.9. The computed tomography scan of the neck demonstrated sublingual hematoma. He was admitted to emergency department observation unit, monitored closely; anticoagulation was reversed with fresh frozen plasma and vitamin K. 26 hours after his arrival to the emergency department, his abdominal pain and melena started. His abdomen tomography demonstrated intestinal submucosal hemorrhage in the ileum. He was admitted to surgical floor, monitored closely, and discharged on day 4.Conclusion. Since the patient did not have airway compromise holding anticoagulant, reversing anticoagulation, close monitoring and observation were enough for management of both sublingual and spontaneous intramural small bowel hematoma.

scholarly journals Impact of CYP2C9 and VKORC1 Polymorphisms on Warfarin Sensitivity and Responsiveness in Jordanian Cardiovascular Patients during the Initiation Therapy

Genes ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 578 ◽  
Author(s):  
Laith AL-Eitan ◽  
Ayah Almasri ◽  
Rame Khasawneh
Keyword(s):  
Warfarin Therapy ◽  
Catalytic Properties ◽  
Warfarin Dose ◽  
International Normalized Ratio ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Haplotype Blocks ◽  
Cardiovascular Patients ◽  
Cyp2c9 Gene ◽  
Vkorc1 Gene

Warfarin is an oral anticoagulant frequently used in the treatment of different cardiovascular diseases. Genetic polymorphisms in the CYP2C9 and VKORC1 genes have produced variants with altered catalytic properties. A total of 212 cardiovascular patients were genotyped for 17 Single Nucleotide Polymorphisms (SNPs) within the CYP2C9 and VKORC1 genes. This study confirmed a genetic association of the CYP2C9*3 and VKORC1 rs10871454, rs8050894, rs9934438, and rs17708472 SNPs with warfarin sensitivity. This study also found an association between CYP2C9 and VKORC1 genetic haplotype blocks and warfarin sensitivity. The initial warfarin dose was significantly related to the CYP2C9*3 polymorphism and the four VKORC1 SNPs (p < 0.001). There were significant associations between rs4086116 SNP and TAT haplotype within CYP2C9 gene and rs17708472 SNP and CCGG haplotype within VKORC1 gene and warfarin responsiveness. However, possessing a VKORC1 variant allele was found to affect the international normalized ratio (INR) outcomes during initiation of warfarin therapy. In contrast, there was a loose association between the CYP2C9 variant and INR measurements. These findings can enhance the current understanding of the great variability in response to warfarin treatment in Arabs.

Warfarin-related outcomes in patients with antiphospholipid antibody syndrome managed in an anticoagulation clinic

2006 ◽  
Vol 96 (08) ◽  
pp. 137-141 ◽  
Author(s):  
Jennifer Downing ◽  
Juan Blackburn ◽  
Edith Nutescu ◽  
Ann Wittkowsky
Keyword(s):  
Oral Anticoagulation ◽  
Warfarin Therapy ◽  
Hospital Admissions ◽  
Anticoagulation Clinic ◽  
Bleeding Complications ◽  
Antiphospholipid Antibody ◽  
Antiphospholipid Antibody Syndrome ◽  
Healthcare Resources ◽  
Clinical Endpoints ◽  
Clinic Setting

SummaryPatients with antiphospholipid antibody syndrome (APA) are at elevated risk of venous and arterial thromboembolic complications. Oral anticoagulation with warfarin is recommended for secondary prevention of thromboembolism, but warfarin-related outcomes have not been systematically investigated when warfarin therapy is managed by a dedicated anticoagulation clinic.The objectives of the study were to evaluate warfarin-related monitoring outcomes, clinical endpoints and the use of healthcare resources as a result of warfarin-related complications in patients with APA compared to a group of patients without APA, all of whom were managed in an anticoagulation clinic setting. A retrospective observational cohort design was used to investigate patients with and without APA, all of whom had a history of venous or arterial thromboembolism, and were matched for age, gender and indication for oral anticoagulation. Thirty-six APA patients taking warfarin were compared to a matched cohort of 36 patients without APA. Monitoring outcomes (time in therapeutic range, clinic visits per year, frequency of warfarin dosing adjustments, reasons for out-of-range INRs) were similar between groups, as was the frequency of major bleeding complications (3.2%/pt-yr vs. 3.1%/pt-yr). However, recurrent thromboembolic events (9.6%/pt-yr vs 0) occurred more frequently in APA patients. APA patients required more emergency room visits (6.4%/pt-yr vs. 1.6%/pt-yr) and hospital admissions (14.4%/pt-yr vs.3.0%/pt-yr) to manage complications of warfarin therapy. In conclusion, despite similar monitoring outcomes obtained in a dedicated anticoagulation clinic setting, adverse clinical outcomes are significantly more frequent in patients with APA syndrome than in those without APA, and require more frequent use of healthcare resources.

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