Warfarin - Wikipedia, the free encyclopedia
: "Because of warfarin's poorly-predictable pharmacokinetics, several researchers have proposed algorithms for commencing warfarin treatment:
* The Kovacs 10 mg algorithm was better than a 5 mg algorithm.
* The Fennerty 10 mg regimen is for urgent anticoagulation
* The Tait 5 mg regimen is for 'routine' (low-risk) anticoagulation
* From a cohort of orthopedic patients, Millican et al derived an 8-value model, including CYP29C and VKORC1 genotype results, that could predict 80% of the variation in warfarin doses. It is awaiting validation in larger populations and has not been reproduced in those who require warfarin for other indications."ISMAAP - UK
: "The CoaguNation Bus Tour provides an excellent opportunity for warfarin patients across the UK and Ireland to learn about the potential benefits of self testing, and to speak to other self testing patients from AntiCoagulation Europe about the positive impact it can have on their lives”.
Gloucester - Kings Square 20 June 9 am to 5 pm
21 June 9 am to 5 pm"
More than 1,000,000 patients
in United Kingdom are living on long-term oral anticoagulation.
ISMAAP activities are focussed around these patients to offer them a better quality of life.
At the conference we launched the Campaign Resource pack for people unable to obtain their testing strips on prescription in the UK.
Warfarin can be reversed with vitamin K, or for rapid reversal (e.g. in case of severe bleeding), with prothrombin complex concentrate (containing only the factors inhibited by warfarin) or fresh frozen plasma depending upon the clinical indication.
Details on reversing warfarin are provided in clinical practice guidelines from the American College of Chest Physicians. For patients with an international normalized ratio (INR) between 4.5 and 10.0, 1 mg of oral vitamin K is effective.
Warfarin necrosis - Wikipedia, the free encyclopedia: "Warfarin necrosis is acquired protein C deficiency due to treatment with the vitamin K inhibitor anticoagulant warfarin. It is a feared (but rare) complication of warfarin treatment. This rare reaction occurs usually between the third and tenth days of therapy with warfarin derivatives, usually in women. Lesions are sharply demarcated, erythematous, indurated, and purpuric and may resolve or progress to form large, irregular, hemorrhagic bullae with eventual necrosis and slow-healing eschar formation. Development of the syndrome is unrelated to drug dose or underlying condition. Favored sites are breasts, thighs, and buttocks. The course is not altered by discontinuation of the drug after onset of the eruption. In initial stages of action, inhibition of protein C may be stronger than inhibition of the vitamin K-dependent coagulation factors (II, VII, IX and X), leading to paradoxical activation of coagulation and necrosis of skin areas. It occurs mainly in patients with a deficiency of protein C. Protein C is an innate anticoagulant, and as warfarin further decreases protein C levels by inhibiting vitamin K, it can lead to massive thrombosis with necrosis and gangrene of limbs."warfarin - Google SearchVitamin K and warfarin medication
: "Anybody beginning a course of warfarin medicine is advised to keep the vitamin K content of their diet constant. If the warfarin dose is established with a constant level of vitamin K intake the INR will not be affected. Problems may arise when vitamin K intakes are varied. If a patient suddenly lowers their vitamin K intake, the INR will increase, and if a patient increases their vitamin K intake the INR will decrease."Warfarin versus aspirin for prevention of thromboe...[Lancet. 1994] - PubMed Result
: "The primary event rate per year was 3.6% with warfarin and 4.8% with aspirin (RR 0.73, p = 0.39). In this older group, the rate of all stroke with residual deficit (ischaemic or haemorrhagic) was 4.3% per year with aspirin and 4.6% per year with warfarin (RR 1.1). Warfarin may be more effective than aspirin for prevention of ischaemic stroke in patients with atrial fibrillation, but the absolute reduction in stroke rate by warfarin is small. Younger patients without risk factors had a low rate of stroke when treated with aspirin. In older patients the rate of stroke (ischaemic and haemorrhagic) was substantial, irrespective of which agent was given. Patient age and the inherent risk of thromboembolism should be considered in the choice of antithrombotic prophylaxis for patients with atrial fibrillation."Adjusted-dose warfarin versus low-intensity, fixed...[Lancet. 1996] - PubMed Result
: "The annual rates of disabling stroke (5.6% vs 1.7%, p = 0.0007) and of primary event or vascular death (11.8% vs 6.4%, p = 0.002), were also higher with combination therapy. The rates of major bleeding were similar in both treatment groups. INTERPRETATION: Low-intensity, fixed-dose warfarin plus aspirin in this regimen is insufficient for stroke prevention in patients with non-valvular AF at high-risk for thromboembolism; adjusted-dose warfarin (target INR 2.0-3.0) importantly reduces stroke for high-risk patients."Aspirin is Safer than Warfarin and Just as Effective for Treating Blocked Arteries in the Brain: National Institute of Neurological Disorders and Stroke (NINDS)
: "In the new study, called the Warfarin Aspirin Symptomatic Intracranial Disease (WASID) trial, investigators at 59 medical centers across the United States, led by Marc I. Chimowitz, M.D., of Emory University in Atlanta, compared warfarin to 1300 milligrams (mg) per day of aspirin in a total of 569 patients for an average of 1.8 years. All of the patients had a greater than 50 percent blockage of a major intracranial artery and had experienced a TIA or non-disabling stroke within the 90 days prior to their enrollment in the study.
The investigators found that about 22 percent of the patients had a subsequent ischemic stroke (caused by blockage of an artery), brain hemorrhage, or death from other blood vessel-related causes, regardless of whether they received aspirin or warfarin. However, the rates of major hemorrhage and death from all causes were significantly higher in the patients treated with warfarin (event rates for aspirin compared to warfarin, respectively, were 3.2 percent vs. 8.3 percent for major hemorrhage and 4.3 percent vs. 9.7 percent for death). Enrollment in the study was terminated earlier than originally planned on the recommendation of an independent Data and Safety Monitoring Board because of concern for the safety of the patients given warfarin
Since warfarin treatment is a more expensive and complicated therapy than aspirin, not using warfarin and preventing the bleeding complications associated with it would save more than $20 million per year in the United States, Dr. Chimowitz estimates.
"The results of this study are only relevant to people with intracranial stenosis," Dr. Chimowitz notes. People who are receiving warfarin for other conditions, such as an irregular heart rhythm (called atrial fibrillation) or clots in the legs or lung, should not stop taking the drug, as studies have found that it is the best option in those conditions, he cautions.
The dose of aspirin used in this study – 1300 mg – is much higher than the daily doses typically prescribed, which range from 81 to 325 mg. While there is some concern that doses of 1300 mg aspirin may increase the risk of gastrointestinal bleeding, the investigators chose this dose because it was the only amount for which earlier studies had provided good preliminary data. "This is the only dose we know is as effective as warfarin for this disease, since it was the only dose studied. We just don't know how other doses of aspirin would stack up," says Dr. Chimowitz. The major bleeding risk on high dose aspirin in WASID was similar to the major bleeding risk in other stroke trials that have evaluated lower doses of aspirin (e.g. 325 mg per day), he adds. Most experts believe there are no advantages to aspirin doses greater than 325 mg for stroke prevention, and the U.S. Food and Drug Administration-approved dose of aspirin for prevention of vascular events is 50-325 mg. Patients should consult their physicians before beginning any long-term or high-dose aspirin treatment regimen.
Even with treatment, the rates of ischemic stroke in this clinical trial were substantially higher than in stroke prevention trials that have evaluated aspirin and warfarin in patients with other causes of stroke. This underscores that patients with intracranial stenosis are at particularly high risk for stroke and that better therapies are needed, the investigators note.
Warfarin Diet: "7. Be aware of foods which are known to be high in vitamin K content. As a general rule, these include most dark green vegetables. Foods highest in vitamin K are brussels sprouts, spinach, broccoli, kale, cabbage, parsley and avocado. It is important to include these foods in your diet, but try to keep your intake of them consistent from week to week. If your diet changes significantly for more than a few days, either through choice or illness, inform your health care professional. Foods highest in vitamin K are:Warfarin Guidelines CPG
Food vitamin k micrograms
Kale (1 cup, raw) 540
Swiss chard (1 cup, raw) 500
Collard greens (1/2 cup, cooked) 440
Spinach (1/2 cup, cooked) 360
Brussels sprouts (5) 289
Watercress (3 cups, raw) 250
Endive (2 cups, raw, chopped) 231
Scallion (2/3 cup, raw, chopped) 207
Broccoli (1/2 cup, cooked) 113
Coleslaw with dressing (3/4 cup) 100
Cabbage (2/3 cup, cooked) 98
Asparagus (7 spears, cooked) 80"
* Most patients require 3-5 days of warfarin before achieving a stable maintenance phase.
* If the patient is receiving TPN, removal of Vitamin K from nutrient solution may be necessary." I am starting with 3mg at 6:00 pm today
Slideshowwarfarin initial loading - Google Search
We have been working with the National Patient Safety Agency on issuing new guidance to help limit the number of adverse events and death from taking vitamin K antagonistsActions that can make anticoagulant therapy safer
: "Anticoagulants are one of the classes of medicines most frequently identified as causing preventable harms and admissions to hospitals. The NPSA has produced the following patient safety alert and support materials to help manage the risks associated with anticoagulants and reduce the risks of patients being harmed in the future."