• Journal of The Korean Society of Clinical Toxicology
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• v.9 no.2
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• pp.113-116
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• 2011

Superwarfarin, such as brodifacoum, is a highly lethal vitamin K antagonist used as a rodenticide. Brodifacoum has a particularly long half-life in the body, which ranges to several months, and therefore requires prolonged treatment with antidotal vitamin K. We experienced a case whereby an 18-year-old male was presented to the hospital with a severe bleeding disorder. It was discovered that he had ingested brodifacoum rodenticide with intent to commit suicide. Despite continual treatment with vitamin K, the bleeding disorder persisted for several months before he recovered. We report this case with literature review.

• Journal of Chest Surgery
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• v.37 no.5
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• pp.448-451
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• 2004

Report of right atrial thrombus complicating pulmonary embolism after cardiac surgery is rare. A 54-year-old woman operated on the atrial septal defect 10 months ago was admitted for left pleuritic pain and dyspnea. Multiple segmental perfusion defects were detected in lung perfusion scan. Transesophageal echocardiography showed a large mobile right atrial mass attached to the free wall of the right atrium with a stalk. Despite the intravenous heparinization for 13 days, follow-up echocardiography revealed the right atrial mass had not diminished in size. The mass which was confirmed as an organizing thrombus was excised under cardiopulmonary bypass. The patient recovered uneventfully and was discharged on warfarin therapy.

• The Journal of Internal Korean Medicine
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• v.33 no.2
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• pp.160-171
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• 2012

Background and Objective : Warfarin is the standard anticoagulation treatment for atrial fibrillation, venous thromboembolism (VTE), and mechanical heart valves. Close monitoring of the International Normalized Ratio (INR) is required due to the drug's very narrow therapeutic window. Many factors can affect INR levels. Drug and food interactions are frequently cited as causes of adverse events with warfarin. We discussed interactions between herbs and warfarin studied in this research. Methods : In this review, PubMed was used to search medical journals. Keywords "warfarin AND interaction" were applied. Results : 55 articles were included. The possibility of correlation between warfarin and single herbal medicines such as Salviae Miltiorrhizae Radix, Angelicae Gigantis Radix, Ginseng Radix Alba, Lycii Fructus, Ginkgo Folium, Menthae Herba, Trigonellae semen was suggested. Furthermore, some herbal compounds interacting with warfarin were reported. The conclusion of studies reporting the effect of herbal medicine on warfarin were controversial due to small size or quality of research. Conculsions : We suggest that we should prescribe therapeutic herbal medicines to patients using warfarin more carefully and do INR follow-up regularly.

• Journal of Chest Surgery
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• v.41 no.2
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• pp.273-276
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• 2008

Since the introduction of extracorporeal cardiopulmonary support of cardiac arrest in 1983, emergent cardiopulmonary support has been used to treat cardiac arrest. Acute massive pulmonary embolism is associated with a high mortality rate and it poses a challenge for both the anesthesiologist and the surgeons especially during operations. This report describes the use of the emergent bypass system in the effective management of an intraoperative massive pulmonary embolism and cardiac arrest in a 56-year-old woman. The patient was discharged on warfarin and there was no recurrence of the pulmonary embolism at the follow-up visit.

• Journal of Korean Medicine Rehabilitation
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• v.20 no.2
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• pp.175-181
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• 2010

Objectives : The purpose of this study is to investigate interaction and safety in administering herb-medicine with warfarin. Methods : For this study, we selected 19 patients who have been taking warfarin, from the ones that have been transferred from western hospital to oriental hospital. During their stay in the oriental hospital, we gave herb-medicine in addition to warfarin. Then we gathered informations and data on sex, age, main indications, and International Normalized Ratio(INR) values of selected patients through Electronic Medical Records(EMR) of Dong-Guk university hospital. Accordingly, we compiled all of the above data for a period of 10 days prior and 10 days post admission(western hospital period and oriental hospital period, respectively). Results and Conclusions : The statistical analysis of the data have revealed that there was no significant change of INR values after giving herb-medicine with warfarin(p=0.586). The result shows that administration of herb-medicine with warfarin is safe and has little drug interaction. However, this study was carried out on small sample size and the interaction with other drugs and various kinds of herb-medicine was not considered. Although we attained a restrictive result from this study, we are able to suggest the safety about co-administration of herb-medicine and warfarin.

• YAKHAK HOEJI
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• v.49 no.2
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• pp.134-139
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• 2005

Warfarin is a widely used oral anticoagulant agent used to treat thromboembolic disease. The purpose of this study was to develop the efficient assay method of warfarin sodium i n human plasma and to assess the pharmacokinetic profile of the warfarin in healthy Korean volunteers. The pharmacokinetics of warfarin administered orally was evaluated after a dose of 10 mg. Warfarin in plasma was assayed using a specific HPLC method with UV absorbance at 304 nm. AUC was 46.33${\pm}9.95{\mu}g/ml.hr$, $C_{max}$ $1.22{\pm}0.22{\mu}g/ml, $T_{max}$$2.50{\pm}1.41$ hr and half-life $43.49{\pm}4.33$ hr. $T_{max}$ was slightly shorter than that in Caucasian (3~9 hr), whereas the half-life was longer than that in Caucasian (10~45 hr, mean: 36 hr). These results suggest that warfarin may have a longer duration in Korean than in Caucasian.

• Korean Journal of Clinical Pharmacy
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• v.23 no.3
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• pp.206-212
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• 2013

Purpose: The aim of this study was to investigate the effect of nimodipine on the pharmacokinetics of warfarin after oral and intravenous administration of warfarin in rats. Methods: Warfarin was administered orally (0.2 mg/kg) or intravenously (0.05 mg/kg) without or with oral administration of nimodipine (0.5 or 2 mg/kg) in rats. The effect of nimodipine on the P-glycoprotein as well as cytochrome P450 (CYP) 3A4 activity was also evaluated. Results: Nimodipine inhibited CYP3A4 enzyme activity with 50% inhibition concentration ($IC_{50}$) of $10.2{\mu}M$. Compared to those animals in the oral control group (warfarin without nimodipine), the area under the plasma concentration-time curve (AUC) of warfarin was significantly greater (0.5 mg/kg, P<0.05; 2 mg/kg, P<0.01) by 31.3-57.6%, and the peak plasma concentration ($C_{max}$) was significantly higher (2 mg/kg, P<0.05) by 29.4% after oral administration of warfarin with nimodipine, respectively. Consequently, the relative bioavailability of warfarin increased by 1.31- to 1.58-fold and the absolute bioavailability of warfarin with nimodipine was significantly greater by 64.1-76.9% compared to that in the control group (48.7%). In contrast, nimodipine had no effect on any pharmacokinetic parameters of warfarin given intravenously. Conclusion: Therefore, the enhanced oral bioavailability of warfarin may be due to inhibition of CYP 3A4-mediated metabolism rather than P-glycoprotein-mediated efflux by nimodipine.

• Korean Journal of Clinical Pharmacy
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• v.30 no.4
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• pp.243-249
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• 2020

Background: Despite the increased use of direct-acting oral anticoagulants, warfarin is still recommended as first-line therapy in patients with mechanical valves or moderate to severe mitral stenosis. Anticoagulation management services (AMSs) are warranted for patients receiving warfarin therapy due to the complexity of warfarin dosing and large interpatient variability. To overcome limited health care resources, we developed a messenger app-based chatbot that provides information to patients taking warfarin. Methods: We developed "WafarinTalk" as an add-on to the open-source messenger app KakaoTalk. We developed the prototype chatbot after building a database containing seven categories: 1) dosage and indications, 2) drug-drug interactions, 3) drug-food interactions, 4) drug-diet supplement interactions, 5) monitoring, 6) adverse events, and 7) precautions. We then surveyed 30 pharmacists and 10 patients on chatbot reliability and on participant satisfaction. Results: We found that 80% of the pharmacists agreed on the consistency of chatbot responses and 44% agreed on the appropriateness of chatbot. Furthermore, 47% of pharmacists said that they were willing to recommend the chatbot to patients. Of the seven categories, information on drug-food interaction was the most useful; 90% of patients said they were satisfied with the chatbot and 100% of patients said they were willing to use it when they were unable to see a pharmacist. We updated the prototype chatbot with feedback from the survey. Conclusion: This study showed that warfarin-related information could be provided to patients through a messenger application-based chatbot.

• Journal of Chest Surgery
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• v.41 no.4
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• pp.430-438
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• 2008

Background: All the patients with mechanical valves require warfarin therapy in order to prevent them from developing thromboembolic complications. According to the ACC/AHA practice guidelines, after AVR with bileaflet mechanical prostheses in patients with no risk factors, warfarin is indicated to achieve an INR of 2.0 to 3.0. After MVR with any mechanical valve, warfarin is indicated to achieve an INR of 2.5 to 3.5. But in our clinical experience, bleeding complications (epistaxis, hematuria, uterine bleeding, intracerebral hemorrhage etc.) frequently developed in patients who maintained their INR within this value. So, we retrospectively reviewed the patients with bileaflet mechanical heart valve prosthesis and we determined the optimal anticoagulation value. Material and Method: From January 1984 to February 2007, 311 patients have been followed up at a national medical center. We classified the AVR patients (n=60) into three groups as follows: an INR from 1.5 to 2.0 in Group I, an INR from 2.0 to 2.5 in Group II and an INR from 2.5 to 3.0 in Group III. We classified the MVR (n=171) and DVR (n=80) patients into four groups as follows: an INR from 1.5 to 2.0 in Group I, an INR from 2.0 to 2.5 in Group II, an INR from 2.5 to 3.0 in Group III and an INR from 3.0 to 3.5 in Group III. We compared the groups for their thromboembolic and bleeding complications by means of the Kaplan Meier method. Result: In the AVR patients, 2 thromboembolic complications and 4 bleeding complications occurred and the log rank test failed to identify any statistical significance between the groups for thethromboembolic complication rate, but groups I and II had lower bleeding complication rates than did group III. Thirteen thromboembolic complication and 15 bleeding complication occurred in the MVR and DVR patients, and the log rank test also failed to identify statistical significance between the groups for the thromboembolic complication rate, but groups I and II had lower bleeding complication rates that did groups III and IV. Conclusion: The thromboembolic complication rate was not statistically different between groups I and II and groups III and IV, but the bleeding complication rates of groups I and II were lower than those of groups III and IV. So this outcome encouraged us to continue using our low intensive anticoagulation regime, that is, an INR of 1.5 to 2.5.

• Tuberculosis and Respiratory Diseases
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• v.65 no.3
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• pp.212-215
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• 2008

Rectus sheath hematoma (RSH) is a rare condition that's caused by a sudden disruption of the deep epigastric vessels or direct damage to the rectus abdominis muscle. This condition is associated with old age, childbirth, abdominal surgery, severe cough, severe sneezing, anticoagulation therapy and/or coagulation disorders. RSH is characterized by abdominal pain and an abdominal mass, so that this is often misdiagnosed as a surgical condition such as appendicitis, intraabdominal abscess, torsion of the ovary and ruptured abdominal aortic aneurysm; this can lead to unnecessary surgery. Thus, we have to be cautious not to miss RSH when a patient with predisposing factors is suffered from abdominal pain and an abdominal mass. We report here on a case of rectus sheath hematoma that was induced by severe cough in a patient who was taking warfarin.