• Journal of Chest Surgery
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• v.56 no.6
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• pp.452-455
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• 2023

Patients who have undergone mechanical valve replacement require anticoagulation therapy with warfarin to prevent thromboembolism. However, administering warfarin to pregnant patients increases their risk of warfarin embryopathy or central nervous system disorders. Consequently, safer alternatives, such as heparin or low-molecular-weight heparin injection, are substituted for warfarin. However, limited research has been conducted on this subject, with no large-scale studies and particularly few investigations involving multiparous patients. A patient who had previously undergone mechanical mitral valve replacement for atrial septal defect and mitral stenosis received anticoagulant therapy with enoxaparin during 2 pregnancies. Upon confirmation of pregnancy, warfarin was replaced with subcutaneously injected enoxaparin with a dosage of 1 mg/kg at 12-hour intervals. The enoxaparin dosage was controlled using an anti-factor Xa assay, with a target range of 0.3-0.7 IU/mL. Intravenous heparin injections were administered starting 3 days prior to the expected delivery date and were continued until delivery, after which warfarin was resumed. No complications were observed during the deliveries.

• Korean Journal of Clinical Pharmacy
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• v.5 no.2
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• pp.17-31
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• 1995

Pharmacist-managed Anticoagulation Service(ACS) was estabilished and the effectiveness of warfarin monitoring by ACS in maintaining therapeutic INR was evaluated. The primary goal of ACS is to maximize the control of therapy, to maintain therapeutic INR and to decrease morbidity and hospitalization caused by inadequate dosage regimen. Clinical pharmacists performed chartreview, laboratory interpretation, recommendations for warfarin dosage adjustments, physician and patient education, and coordination of follow-up in ACS. Patients receiving warfarin sodium were evaluated via retrospective chart review. Sixty-two patients were referred to ACS by primary physicians were compared with 117 patients in the physician-amtrolled group. The ACS patients maintained $88.6\%$ in the therapeutic range for anticoagulant therapy and the control group maintained $63.7\%$, where the difference was statistically significant.(P<0.001) The ACS improved warfarin dose determination, PT stability, patient compliance and provided improved therapy compared with the control group. ACS offers safe and efficient anticoagulant therapy in the ambulatory setting.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.46 no.4
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• pp.228-234
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• 2020

Objectives: The number of patients undergoing oral anticoagulant therapy for cardiovascular and cerebrovascular disease is increasing. However, the risk of bleeding after tooth extraction in patients receiving warfarin is unclear. Here, we assess the risk of bleeding after tooth extraction in patients on warfarin. Materials and Methods: The study included 260 patients taking warfarin who underwent tooth extraction (694 teeth). The patients were divided into those whose teeth were extracted while they were taking warfarin, those who discontinued warfarin before extraction, and those who underwent extraction while receiving heparin bridging therapy. Bleeding complications in the two groups were compared. Results: Of the 260 patients, 156 underwent extraction while taking warfarin, 70 stopped taking warfarin before extractions, and 34 received heparin bridging therapy and stopped taking either medication before extractions. Bleeding complications occurred in 9 patients (3.5%) and 9 tooth sites (1.3%). Among the 9 patients with bleeding complications, 6 underwent extraction while taking warfarin, 2 stopped warfarin before extraction, and 1 underwent extraction after receiving heparin bridging therapy. No significant difference was seen between patient groups regarding bleeding after extractions (P=0.917). Conclusion: Warfarin use does not increase the risk of post-extraction bleeding and can therefore be continued during tooth extraction.

• Korean Journal of Bronchoesophagology
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• v.4 no.2
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• pp.235-239
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• 1998

Warfarin sodium is a widely used oral anticoagulant and it sometimes causes hemorrhage in various sites such as traumatic or operative wounds, urologic organs, gastrointesitnal tract and subcutaneous tissues. Warfarin induced hemorrhage in upper respiratory tract causing upper airway obstruction is extremely rare. Despite the life-threatening nature of this complication, the symptoms are obscure like sore throat or hoarseness, suggesting infection and early diagnosis can be delayed. Careful medical history is emphasized When bleeding is observed, the patient should be admitted for close observation and prompt treatment. Recently we have exrperienced a case of laryngeal and upper tracheal submucosal hemorrhage induced by long term warfarin in 64 years old mm. We described the case with a review of the literature.

• The Journal of the Korean dental association
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• v.57 no.10
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• pp.623-628
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• 2019

Warfarin is an anticoagulant involved in the production of vitamin K dependent blood clotting factors. Dentists should be familiar with the appropriate assessment methods and considerations for the treatment of patients taking warfarin. Dental surgery with the moderate risk of bleeding can be performed without stopping the drug through preoperative examination of the INR(international normalized ratio) value and evaluation. When performing a surgery with a high risk of bleeding, it is necessary to evaluate whether the drug can be discontinued, what the duration is, and the risk of discontinuation. Hemostasis can be obtained by local methods in most cases of postoperative bleeding in patients taking appropriately adjusted doses of warfarin.

• The Korean Journal of Pain
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• v.9 no.1
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• pp.271-274
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• 1996

Epidural hematoma during anticoagulant therapy is a rare complication of central neural blockade, but it may result in serious neurologic sequelae. A 61-year-old male receiving warfarin due to heart failure was referred to the pain clinic for control of severe herpetic neuralgia. Epidural catheterization was done at $T_{8-9}$ interspace. At that time, PT and aPTT were extremely prolonged. The next morning, severe back pain, motor paralysis and urinary difficulty developed. On spine MRI, epidural hematoma was detected at $T_{8-9}$ interspace. Four days later, he died due to underlying diseases. Central neural blockade in patient with anticoagulant therapy is contraindicated in most cases. If is undertaken, close observation of patients's neurologic functions and monitoring of coagulation profiles(PT, aPTT, etc) are necessary. If epidural hematoma develops, early surgical decompression is mandatory.

• Journal of Chest Surgery
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• v.33 no.6
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• pp.502-506
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• 2000

Background: Anticoagulant therapy can be required during pregnancy with prosthetic heart valves. Warfarin and heparin provide real protection against thromboembolic phenomena, but they also carry serious risks for the fetus and the mother. In an attempt to identify the best treatment for pregnant women with cardiac valve prostheses who are receiving anticoagulant, we studied 19 pregnancies, the warfarin was discontinued and heparin was administered every 12 hours by subcutaneous injection in doses adjusted to keep the midinterval aPTT in the therapeutic range(at least 2-2.5 control) from the conception to the 12th week of gestation and oral antiocagulant was then administered until the middle of the third trimester in the therapeutic range(at least 2 INR), and heparin therapy was restared until delivery. Also in order to avoid an anticoagulant effect during delivery, it has been our practice to instruct women to either discontinue their heparin injections with the onset of labur or to stop heparin injections 12 hours prior to the elective induction of labour. Result: The outcome of 19 pregnancies managed with above protocol was spontaneous abortion in 3 cases, voluntary termination in 2 cases, premature delivery at 35 weeks in 1 case and delivery at full-term in 14 cases. There was no maternal morbidity and moratality and fetopathy. Conclusion: We conclude that in the second and third trimester of pregnancy, warfarin provide effective protection against thromboembolism, Oral antiocagulant therapy should be avoided in 2 weeks before delivery because of the risk of serious perinatal bleeding caused by the trauma of delivery to the anticoagulated fetus. However, the substitution of heparin at first trimester and 2 weeks before delivery reduce the incidence of complications.

• Journal of Veterinary Clinics
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• v.20 no.1
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• pp.74-78
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• 2003

We executed this experiment to observe side effects of warfarin, the anticoagulant that is used for preventing thrombus in cardiovascular surgery for calves. The 6 calves(70-130 kg) were used in this experiment regardless of sexes. We administered warfarin at 0.07 mg/kg daily for 25 days. Blood was collected before warfarin administration, every five days for 30 days. PCV, RBC, WBC, fibrinogen, total protein and platelet as blood test, prothrombin time (PT) as blood coagulation test, and AST, SDH, total bilirubin, BUN and creatinine as serum biochemical tests were measured. As the result of the experiment, PT has been gradually increased after warfarin administration. It has been gradually increased and remains within the therapeutic range from the third day to the 28th day. PCV and RBC were decreased significantly from the value before the administration (p < 0.05). In the serum biochemical test, SDH shows significant increase comparing the value before the administration (p < 0.05). AST and total bilirubin were increased gradually from the value before the administration. Considering the result of the experiment, to give wafarin to prevent thrombus in cardiovascular surgery, we can get anticoagulation effect with minimal administration(0.07 mg/kg, PO) from the third day of the administration. However because of the decreased PCV and RBC, it may cause anemia. It may cause damage to liver based on the result of serum biochemical test.

• Journal of Chest Surgery
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• v.32 no.11
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• pp.1023-1030
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• 1999

This is a retrospective study of 42 pregnancies from 33 women with prosthetic heart valves who were on anticoagulation regimen prior to or during their pregnancy. Material and Method: Of the 17 women with bioprosthesis, 15 had 21 pregnancies following cessation of the anticoagulation therapy which resulted in the delivery of 20 healthy babies and 1 abortion. Remaining 2 had 3 pregnancies maintained with heparin, resulting in 2 healthy babies and 1 spontaneous abortion. Result: Among 16 women with mechanical heart valves, there were 7 pregnancies during which warfarin was used and this was associated with 4 fetal wastages(2 therapeutic abortion, 1 spontaneous abortion and 1 stillbirth with cerebral hemorrhage). However, in pregnancies where heparin was used, there was no fetal wastage. A patient who did not take anticoagulant for the first trimester and took warfarin for the remaining period and a patient who did not take anticoagulant during pregnancy delivered normal babies. There was an other fetal wastage in a patient on anti-platelet therapy for the first trimester and warfarin therapy for the remaining periods. There was 1 minor petechial complication in a heparin administered group. Conclusion: The study indicates that woman with bioprosthetic heart valves can go through pregnancy without undue risks or complications. On the other hand, the use of warfarin during pregnancy in women with mechanical heart valves, was shown to be associated with unacceptable high risk for the fetus. However, in the same group of women, judicious use of heparin during pregnancy was accompanied by a much reduced risk. The safety and adequate therapeutic range of heparin usage under such circumstances are subject to further studies.

• Korean Journal of Clinical Pharmacy
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• v.26 no.3
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• pp.201-206
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• 2016

Objective: Direct current cardioversion for atrial fibrillation could be associated with the risk of thromboembolic events. Anticoagulation therapy with warfarin (INR 2.0-3.0) is recommended 3 weeks before and 4 weeks after cardioversion to reduce the risk of thromboembolism. This study evaluated warfarin therapy in pharmacist-managed anticoagulant services (ACS). Methods: This retrospective study was performed in 106 patients with atrial fibrillation from 2012 to 2013. The primary efficacy endpoint was the composite of stroke, transient ischemic attack, myocardial infarction, and cardiovascular death. The primary safety measure was major bleeding. To evaluate the peri-procedural effects of warfarin treatment, we studied whether target INR was maintained, as well as the maintenance period of the therapeutic range. Quality of treatment was measured by time in therapeutic range (TTR) by using the Rosendaal method. Results: There were no thromboembolic events, but TEE examination at time of cardioversion showed a left atrial thrombus in three patients (2.8%). Bleeding complications after cardioversion occurred in 2 patients (1.9%). The average INR value at the time of cardioversion was $2.59{\pm}0.8$, and was within the therapeutic range in 83 patients (78%). Analysis of the patients in whom the value was within the therapeutic range twice consecutively showed that the ratio of TTR was 80% and the therapeutic range was maintained in 67 patients (63%) for an average of 4.90 weeks prior to cardioversion. Similarly, 76 patients (72%) had a stable INR within the therapeutic range for an average of 5.70 weeks and a mean TTR of 83%. Conclusion: Pharmacists significantly contributed to appropriate warfarin treatment with close monitoring during cardioversion. Likewise, active pharmacist monitoring and systemic management should be considered to reduce thromboembolism and bleeding complications in the peri-cardioversion period.