In this section : Cardiac
: Haematology and Thrombosis
Myeloma
Warfarin
Anticoagulation for AF, DVT and PE
Orthopaedic VTE Risk Assessment
Haemolytic Anaemia
Platelet Transfusion
Parenteral Iron in Adults >18 Years
Pulmonary Embolism
Deep Vein Thrombosis of Lower Extremities
Bleeding with Other Antithrombotics
Low Molecular Weight Heparin
Haematinic Testing
Thromboprophylaxis for Non-Covid Patients
Thrombophilia Screening
Antithrombotics in Hip Fracture
Reversal of Warfarin
Lumbar Puncture, Antiplatelet & Anticoagulant Drugs
Antithrombotics & Surgery
Iron Deficiency Anaemia
Unfractionated Heparin Infusion
Massive Pulmonary Embolism
Anticoagulation for AF, DVT and PE
Last updated 18th March 2024
Choice of DOAC
- We used to recommend edoxaban for AF and apixaban for VTE but as of January 2024, apixaban is recommended for all indications that require a DOAC.
Dosing is Important
- It is vital to prescribe the appropriate dose for patients.
- Prescribing too low a dose puts the patient at risk of embolic complications, prescribing too high a dose puts the patient at risk of significant bleed
Anticoagulation for Atrial Fibrillation (AF) and Atrial Flutter
- Apixaban is indicated for paroxysmal and persistent AF and atrial flutter provided the patient does not have severe mitral stenosis or a mechanical heart valve, after estimating benefits and risks using the CHA2DS2VASc score.
- Generally speaking benefits outweigh risks when CHA2DS2VASc score ≥1 in men and ≥2 in women
- The usual dose of apixaban for AF and flutter is 5mg bd
- If at least two out of the following three criteria are met, then the dose is 2.5mg twice daily:
- Age 80 years or over
- Body weight less than 61kg
- Creatinine 133 micromol/L or over
- If creatinine clearance is 15 – 29ml/min, then the dose is 2.5mg twice daily
Anticoagulation for VTE
- Apixaban is our first line oral anticoagulant for the treatment of clinically suspected or confirmed VTE. Apixaban can be started immediately and continued once VTE has been confirmed.
- There is no need to use dalteparin in the run up to VTE confirmation unless the patient is unstable or apixaban is contraindicated for that patient.
- Do not use apixaban if creatinine clearance is <15ml/min. Use with caution if creatinine clearance is between 15 and 29ml/min.
- The dose of apixaban for treatment of VTE is 10mg twice daily for 7 days, reducing to 5mg twice daily for the duration of treatment (up to 6 months). Please specify duration of treatment.
- If a decision is made to anticoagulate the patient for longer than 6 months in order to prevent recurrence of VTE, then the dose should be reduced to 2.5mg twice daily.
Dalteparin Dosing
Patient's Weight (kg) | Dose |
---|---|
<46 | 7,500 units daily |
46-56 | 10,000 units daily |
57-68 | 12,500 units daily |
69-82 | 15,000 units daily |
>82 | 18,000 units daily |
Second Line Edoxaban for AF, DVT and PE
- Consider edoxaban as a second line choice it, for example, a patient might struggle with twice daily medication.
- Dose of edoxaban varies by weight and renal function
- You must calculate creatinine clearance using the Cockcroft Gault equation either manually or using an app such as MDCalc – Creatinine Clearance Calculator. Do not use eGFR. Use actual body weight for the calculation.
Creatinine Clearance | Dose if patient weight 60kg or less | Dose if patient weight 61kg or more | Dose if patient also taking ciclosporin, dronedarone, erythromycin, ketoconazole |
---|---|---|---|
<15 ml/min | Avoid | Avoid | Avoid |
15-49 ml/min | 30mg daily | 30mg daily | Avoid |
50-100 ml/min | 30mg daily | 60mg daily | 30mg daily |
100 ml/min | Avoid | Avoid | Avoid |
Extremes of Body Weight
- Patients at extremes of body weight were not excluded from the trials and subset analysis from these trials does not suggest there is any difference in outcome in these patients.
- Our advice is to prescribe apixaban for these patients, using the doses recommended above.
- Some clinicians may prefer to use warfarin in these circumstances, so best to check with the consultant in charge of the case.
Patients with Malignancies
- If it is appropriate to anticoagulate the patient, then apixaban can be used at the licensed doses.
- Seek specialist advice before prescribing. More information available via OOQS.
Patients Taking Antiplatelets
- As a general rule, stop antiplatelets when the decision to prescribe anticoagulants is made.
- In most cases the concomitant prescribing of antiplatelets and anticoagulants increases the risk of significant bleed without reducing cardiovascular risk. However, there will be exceptions to this – for example, recent MI.
- Discuss with the appropriate specialist if in doubt.
Renal Function
- Creatinine clearance should be calculated based on actual body weight.
- Check creatinine clearance annually, or more often if clinically appropriate due to deteriorating renal function. For example if CrCl 15-30ml/min recheck 3 monthly and 30-50ml/min recheck 6 monthly.
Falls Risk
- Many patients are not anticoagulated adequately due to their risk of falls and potential bleeds.
- Where possible, discuss the risks and benefits of anticoagulation with patients and their family/carers so that informed choices can be made.
- Calculate CHA2DS2VASc scores to aid decision making.
- If the decision is made to anticoagulate, DO NOT reduce the dose due to an increased falls risk – this merely results in ineffective anticoagulation whilst still putting the patient at risk of a significant bleed.
Contraindications
- This list is not exclusive, please check the BNF or SPC for up to date prescribing information.
- Avoid apixaban if any of the following present:
- Replacement mechanical heart valves
- Moderate-severe mitral stenosis
- Antiphospholipid syndrome
- Pregnant breastfeeding or planning a pregnancy
- Liver disease associated with cirrhosis and/or coagulopathy
- Uncontrolled severe hypertension
- Concomitant treatment with any other anticoagulants e.g. warfarin, UFH or LMWH
- Lesion or condition, if considered to be a significant risk for major bleeding e.g. recent GI bleed
- Patients pre or post VTE thrombolysis
Links
- UK-GOV Direct-acting oral anticoagulants (DOACs): reminder of bleeding risk, including availability of reversal agents
- Active Cancer – Lothian Online Oncology Quality System Anticoagulation Guidance
- Warfarin
- DOAC Therapy: PE & DVT – Patient Information Leaflet
- DOAC Therapy: AF – Patient Information Leaflet
Updated by Alison Moore and Chris Isles