when should you restart warfarin

by Victor Cartwright Published 2 years ago Updated 2 years ago

If the patient is tolerating oral intake, and there are no unexpected surgical issues that would increase bleeding risk, restart warfarin 12 to 24 hours after surgery.
If the patient received preoperative bridging therapy (high thromboembolic risk) and underwent a minor surgical procedure, resume LMWH or UFH 24 hours after surgery. ...

Clinicians typically restart warfarin at the patient's prior maintenance dose,⁶^,⁷ although in a previous study, we found that it took a median of 20.5 days at the prior maintenance dose to reach a therapeutic INR⁸; prolonged LMWH therapy is needed during this time.

Full Answer

When should warfarin be restarted after surgery?

If the patient is tolerating oral intake, and there are no unexpected surgical issues that would increase bleeding risk, restart warfarin 12 to 24 hours after surgery. If the patient received preoperative bridging therapy (high thromboembolic risk) and underwent a minor surgical procedure, resume LMWH or UFH 24 hours after surgery.

When should warfarin be taken at a lower dose?

In these patients Warfarin should be started at a lower dose (less than 5 mg per day). These include elderly persons, patients after surgery, malnurished patients, patients with liver disease and patients receiving medications that may affect the metabolism of Warfarin (such as amiodarone). When starting warfarin is heparin overlap necessary?

How long does it take for INR to drop after stopping warfarin?

Almost all patients will achieve an international normalized ration (INR) of < 1.5 within 4 - 5 days of stopping warfarin, 9 although patients with a higher (2.5 – 3.5) target INR and the elderly (> 70 years) will require a longer period of warfarin withdrawal before surgery.

When to start bridging LMWH after warfarin?

Ideally, bridging LMWH should be started once the patient’s INR falls below target range, which will be around 36 hours after the last dose of warfarin. Treatment dose LMWH should be withheld for 24 hours, and prophylactic dose for 12 hours before the procedure.

When should I restart warfarin after bleeding?

The optimal time to resume anticoagulation therapy remains unclear, but based on the available information, it appears that around 2 weeks may provide the best balance among GIB recurrence, thromboembolism, and mortality risks.

When should you restart anticoagulation in patients who suffer an intracranial bleed who also have a prosthetic valve?

In patients with prosthetic valves, in situ anticoagulation in the form of heparin can safely be restarted as early as 3 days and switched to oral anticoagulation in the form of warfarin at 7 days without major concerns of bleeding.

When do you need to bridge warfarin?

How Is Bridging Anticoagulation Given? After warfarin is stopped, 5 to 6 days before surgery (to allow sufficient time for its anticoagulant effect to wane), bridging anticoagulation is started 3 days before surgery, with the last dose given 24 hours before surgery.

When do you restart anticoagulation after subdural?

These studies generally included few patients who were followed at a single center and had limited follow-up. Several of the authors and the American Stroke Association13 suggest restarting anticoagulation after a period of 7 to 14 days following intracranial hemorrhage.

How long can you hold anticoagulation with a mechanical valve?

concluded that in patients with mechanical heart valves without any prior history of systemic embolization, anticoagulation could be safely withheld for one to two weeks with minimal risk of thromboembolism [23].

How do you restart warfarin?

Upon restarting warfarin in the setting of known prior maintenance dosing, use of higher warfarin doses (about 1.5 times the usual maintenance dose) for 2 or 3 days, followed by step-down to the maintenance dose, expedites the achievement of a therapeutic INR.

What INR level is vitamin K?

A 1.0-mg vitamin K dose is likely most appropriate for patients with INR values between 4.5 and 10. The fear of over-correction of the INR has limited the widespread use of vitamin K; however, our review suggests that this occurs infrequently when small doses are administered orally.

What should I do if my INR is too low?

If the patient is asymptomatic and the low level is picked up on a routine lab draw, then the treatment can range from simply monitoring the level if slightly low, increasing the patient's oral intake of Vitamin K in diet or increasing the dose of the patient's anticoagulant.

What does bridging warfarin mean?

'Bridging” is a term that refers to the use of short-acting anticoagulants (heparin or LMWH) for a period of time during interruption of warfarin therapy when the INR is not within a therapeutic range.

How long do you bridge warfarin?

Bridging will begin 1 to 2 days after you stop warfarin. Warfarin is stopped about 4 to 5 days before your procedure or surgery. During this time, your blood levels of warfarin slowly drop. Bridging will be started again after your procedure or surgery, when it is safe.

Why do you need a heparin bridge?

Therefore, heparin is often used as a “bridge” when initiating warfarin therapy in patients with AF, not only because physicians feel a need to begin anticoagulation as soon as possible for stroke prevention but also because they want to protect patients from this presumed transient hypercoagulable state.

What does a subtherapeutic INR mean?

1. Less than adequately treated. 2. Taking a drug with a blood level below a desired treatment range. Patients using warfarin for atrial fibrillation, for example, have subtherapeutic anticoagulation when their international normalized ratio (INR) is below 2.0.

Usual Adult Dose for Prevention of Thromboembolism in Atrial Fibrillation

Initial dose: 2 to 5 mg orally once a day Maintenance dose: 2 to 10 mg orally once a day Target INR: 2.5 (range: 2 to 3) Duration of therapy: Indefinite Comments: -For patients with atrial fibrillation (AF) and prosthetic heart valves, target INR may be increased depending on valve type, valve position, and patient factors. -Initial dose is influenced by age, race, body weight, gender, concomitant medications, comorbidities, genetic variation, and possibly other factors. -Dosage and administration must be individualized according to the patient's INR and condition being treated. Use: Prophylaxis and treatment of thromboembolic complications associated with AF..

Usual Adult Dose for Thromboembolic Stroke Prophylaxis

Usual Adult Dose for Myocardial Infarction

Initial dose: 2 to 5 mg orally once a day Maintenance dose: 2 to 10 mg orally once a day INR: 2 to 3 Duration of therapy: At least 3 months after myocardial infarction Comments: -Initial dose is influenced by age, race, body weight, gender, concomitant medications, comorbidities, genetic variation, and possibly other factors. -Dosage and administration must be individualized according to the patient's INR and condition being treated. Use: Reduction in the risk of death, recurrent myocardial infarction (MI), and thromboembolic events such as stroke or systemic embolization after myocardial infarction..

Usual Adult Dose for Myocardial Infarction - Prophylaxis

Usual Adult Dose for Deep Vein Thrombosis - Prophylaxis

Initial dose: 2 to 5 mg orally once a day Maintenance dose: 2 to 10 mg orally once a day Target INR: 2.5 (range: 2 to 3) Duration of therapy: -Deep venous thrombosis (DVT) or pulmonary embolism (PE) secondary to a reversible risk factor: 3 months -Unprovoked DVT or PE: At least 3 months; evaluate risk-benefit ratio of long-term treatment after 3 months. -Two episodes of unprovoked DVT or PE: Indefinite; periodically reassess risk-benefit ratio of continuing such treatment. Comments: -Initial dose is influenced by age, race, body weight, gender, concomitant medications, comorbidities, genetic variation, and possibly other factors. -Dosage and administration must be individualized according to the patient's INR and condition being treated. Use: Prophylaxis and treatment of venous thrombosis and PE..

Usual Adult Dose for Pulmonary Embolism

Usual Adult Dose for Deep Vein Thrombosis - First Event

What is the preoperative management of warfarin?

Preoperative management of warfarin therapy consists of timely discontinuation of warfarin and replacement (known as “bridging”) with therapeutic low molecular weight heparin (LMWH) or unfractionated heparin if the risk of thrombosis is considered to be sufficiently high. Almost all patients will achieve an international normalized ration (INR) of < 1.5 within 4 - 5 days of stopping warfarin, 9 although patients with a higher (2.5 – 3.5) target INR and the elderly (> 70 years) will require a longer period of warfarin withdrawal before surgery. Patients with a high risk of thromboembolism or stroke may benefit from bridging with heparin during the preoperative period, either as outpatients (LMWH subcutaneously) or inpatients (unfractionated heparin intravenously) by shortening the duration of subtherapeutic anticoagulation.

When to check INR after product infusion?

Check INR immediately after product infusion and prior to surgery to document correction. If INR not corrected, consider repeat administration of PCC or FP in consultation with specialist.

How long does prothrombin concentrate work?

For urgent procedures, use of prothrombin complex concentrate is highly effective in rapidly reversing warfarin anticoagulant activity and has a duration of action of ~ 6 hours. The use of bridging heparin therapy is dependent on the risk of thrombosis.

Is warfarin used for surgery?

The management of warfarin therapy in patients undergoing surgery or other invasive procedures involves a fine balance between the risk of hemorrhage if the procedure was performed while on warfarin, and the risk of thrombosis if warfarin was discontinued. The thrombotic risk in the perioperative period depends on pre-existing conditions, ...

How long is a short action?

Short duration of action at ~4 hours.

When to give LMWH?

If indicated, give therapeutic dose of LMWH on day 4, day 3, and day 2 in consultation with a haematologist at the closest referral centre/major hospital or thrombosis clinic. Last dose of LMWH is generally not given any later than 24 hours before the procedure.

When to check INR before surgery?

Check INR the day before procedure to ensure it is lower than the goal INR (< 1.5 for most procedures). If INR is higher than goal INR, discuss with physician performing procedure.

How long after surgery can you take heparin?

Resumption of bridging anticoagulation too early, especially the use of therapeutic-dose heparin within 24 hours after surgery, is associated with a two- to fourfold increased risk for major bleeding compared with no bridging or prophylactic-dose heparin.

How long does it take for rivaroxaban to work?

In general, rivaroxaban can be restarted one day after a low/moderate bleeding risk procedure and two days after a high bleeding risk procedure. Since rivaroxaban has a rapid onset of action, caution should be used in patients who have had major surgery or other procedures associated with a high bleeding risk.

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What appendix is used for parenteral anticoagulant?

5 If patient is on parenteral anticoagulant, see Appendix E; if on warfarin, see Appendix F; if on DOACs, see Appendix G

How long to hold VKA before dental procedure?

1 For moderate risk of bleeding dental procedures in patients on vitamin K antagonists (VKA), either continue VKA in combination with a pro-hemostatic mouthwash or hold VKA 2-3 days prior to procedure

How long should I wait to take warfarin?

The BSH recommends withholding warfarin for 5 days before minor procedures, and the ASRA recommends withholding it for 4–5 days before neuraxial anaesthesia. 3 10 The rate at which the INR falls, once warfarin is withheld, varies considerably between individuals; it will take longer for the INR to fall in the elderly, and in those with a higher initial INR; therefore, the INR should be checked on the day of the procedure. 10 25 The BSH recommend an INR <1.5 for minor procedures, and the ASRA recommend this threshold also for neuraxial anaesthesia, 3 10 whereas the ESA recommend an INR ≤1.4 before spinal puncture or regional anaesthesia. 4 In patients who have recently stopped warfarin, a normal INR in the first 1–3 days reflects the return of factor VII activity, but there still may not be full haemostasis due to factor II and X concentrations taking slightly longer to normalise. 3

When should anticoagulant treatment be postponed?

If a patient has a complex medical background, or has started anticoagulant or antiplatelet treatment within the past 12 months, then the procedure, and any periprocedural potential changes in antithrombotic medication, should be postponed pending a discussion with the relevant specialty.

How long does it take to restart LMWH?

When is safe to restart LMWH is unclear; guidance ranges from 2 to 4 hours in the European guidelines (with an atraumatic procedure) to up to 24 hours in the American ones. 2 6 33 The discrepancy between these two guidelines may well stem from the aftermath of a high number of spinal epidural haematomata in the USA between 1993 and 1998 following the introduction of enoxaparin 30 mg twice a day for thromboprophylaxis, with no guidance on intervals between administration and neuraxial procedures; the incidence at the same time was much lower in Europe, where an enoxaparin 40 mg once-daily dosing regimen was mainly used. 2 4 The UK obstetric guidelines for neuraxial anaesthesia advise 4 hours for prophylactic or treatment dose anaesthesia, with consideration to increasing this to 24 hours in the procedure was traumatic. 5

How long does unfractionated heparin last?

Unfractionated heparin has a shorter half-life than LMWH (1–2 hours vs 3–7 hours). When given intravenously, spinal puncture should not be performed for 2–4 hours after the last dose according to the ASRA, and not for 4–6 hours according to the ESA; the ASRA and UK guidelines also recommend that the patient should have a normal APTT ratio (≤1.4) before the procedure. 3–5 Unfractionated heparin can be restarted 1 hour after the procedure. 3 4 33

When should a patient have a bridging treatment dose LMWH?

Patients at high risk for thrombosis should have bridging treatment dose LMWH, these include: patients with a venous thromboembolism within the previous 3 months, or previous venous thromboembolism while on therapeutic anticoagulation, those with mechanical heart valves other than those with a bileaflet aortic valve and no other risk factors, those with atrial fibrillation and previous stroke or transient ischaemic attack in the past 3 months or previous stroke/transient ischaemic attack and CHA 2 DS 2 -VASc score of ≥3.

Is suspension of antithrombotic medication a risk?

Suspending antithrombotics also carries risk ; usually of cardiac or cerebral ischaemia, or of venous thromboembolism. Therefore, the potential benefits of performing an LP must be weighed against the risk of temporary suspension of antithrombotic treatment. High-risk patients should have appropriate bridging treatment, discussed in more detail below; however, this is still not without increased risk of thrombosis. If a patient has a complex medical background, or has started anticoagulant or antiplatelet treatment within the past 12 months, then the procedure, and any periprocedural potential changes in antithrombotic medication, should be postponed pending a discussion with the relevant specialty. Each patient should be considered on an individual basis, as there is likely to be several factors influencing the balance of risk and benefit.

Who created anticoagulation reverse agents?

Anticoagulation Reversal agents for patient on DOACs. Created and Contributed by Javier Polania Gutierrez, MD

What is perioperative anticoagulation management?

Management of perioperative anticoagulation requires an interprofessional approach to determine the duration and discontinuation of temporary interruption of anticoagulation. Parenteral anticoagulation during temporary interruption may be required in certain circumstances based on the patient's and procedure's individualized risks and benefits. This activity explains the recommendations for perioperative management of anticoagulation for patients with nonvalvular atrial fibrillation undergoing non-cardiac surgery.

What is optimal management of thromboembolic and bleeding risks?

The optimal management of these patients is thus achieved through a balance between thromboembolic and bleeding risks. Several case-based considerations affect the decision of whether or not to interrupt anticoagulation or anti-aggregation therapy before surgery. These include an evaluation of an individual's underlying bleeding risk, the risk of bleeding associated with the surgical procedure, the timing of interruption and resumption of anticoagulation therapy, and whether to use bridging therapy. These are all typical questions that will be addressed in this review.

What is anticoagulation therapy?

Anticoagulation therapy is most commonly indicated in the presence of atrial fibrillation (AF), deep venous thrombosis (DVT), pulmonary embolism (PE), and after placement of prosthetic heart valves. Patients who have undergone percutaneous coronary interventions are typically on dual antithrombotic therapy, as well as patients with a past medical history of stroke, coronary artery by-pass grafting and essential thrombocytosis could require antithrombotic therapy.

What is the most common anticoagulant?

These are also called coumarins. The most recognized and widely used drug of this group is warfarin, which has been available for more than 50 years. The mechanism of action of warfarin is the inhibition of the 2,3 epoxide reductase enzyme, responsible for the cyclical conversion of oxidized vitamin K to a reduced state. The latter is necessary as a cofactor for the carboxylation of glutamic acid at the N-terminus of coagulation factors. Without gamma carboxyglutamate residues, clotting factors II, VII, IX, and X cannot bind to the divalent calcium necessary for normal activation. However, the inhibition of carboxylation also affects the production of protein C and S anticoagulants. This creates a transient procoagulant state that can be explained by the shorter half-life of these anticoagulants (8 and 30 hours), compared to factor II and factor X (60 and 72 hours). This phenomenon is more frequent, with higher doses of vitamin K antagonists at the beginning of anticoagulation therapy. [8] Warfarin is a racemic mixture of the R and S stereoisomers of the drug; the S isomer is 3-5 times more potent than the R isomer. The half-life of warfarin is 36 to 42 hours (S isomer 29 hours, R isomer 45 hours); nonetheless, it can be altered by several factors. In practice, warfarin is a drug of difficult titration due to the high number of pharmacological interactions and genetic variations that can affect its metabolism. [9]

How long does fondaparinux last?

The plasma half-life of fondaparinux is approximately 15 to 17 hours. Its anticoagulant activity persists even 2 to 4 days after the last dose of the drug in a person with normal renal function. [11]

How long does ticagrelor stay in your system?

After a loading dose of ticagrelor, the maximum antiplatelet effect is achieved within 2 hours, plasma half-life is 8 to 12 hours, and steady-state concentration in 2 to 3 days. Due to the reversible effect of ticagrelor on platelets, it is recommended to be suspended 5 days before surgery. [4] On the other hand, cangrelor is a direct, reversible, and intravenously administered drug that inhibits the P2Y12 receptor. Cangrelor can inhibit 95% to 100% of platelet activity within the first two minutes of administration; the plasma half-life of cangrelor (3 to 6 minutes) allows recovery of 80% to 90% platelet function within 60 to 90 minutes of discontinuing the intravenous infusion. [7]