Aimee Lettis from the GP Update team gives us short, sharp nuggets of clinical information for sessional GPs.
You are probably aware of the NOACs (novel oral anticoagulants), new drugs that can be used in place of warfarin. You probably won’t be using them very often but here’s an overview to help you when faced with a patient asking to start one of them or prescribing for the first time. There are three of them: dabigatran, rivaroxaban and apixaban and currently they have the following license/approval:
- Stroke prevention in non-valvular atrial fibrillation (AF)
- All 3 are licensed for this indication.
- Apixaban is awaiting NICE/SIGN approval.
- Prevention of venous thromboembolism (VTE) after elective knee/hip replacement
- All 3 are licensed and approved by NICE.
- Treatment of VTE
- Only rivaroxaban is licensed & approved (NICE).
We have summarised the key information about the NOACs and compared the 3 in this table:
|Dabigatran (Pradaxa)||Rivaroxaban (Xaralto)||Apixaban (Eliquis)|
|Preparation||110mg & 150mg tablets||10mg, 15mg & 20mg tablets||2.5mg tablets|
|Dose in AF||110mg or 150mg twice daily.||20mg once daily reducing to 15mg once daily if eGFR 30-60.||5mg twice daily Reduce to 2.5mg twice daily if ≥ 2 of following:≥ 80y, ≤ 60kg or Cr ≥ 133.|
|Dose for VTE prevention post-surgery||220mg once daily for:10d post knee surgery4-5w post hip surgery||10mg once daily for:2w post knee surgery5w post hip surgery||2.5mg twice daily for:10-14d post knee surgery32-38d post hip surgery|
|Dose for VTE treatment||Not licensed||15mg twice daily for 21d then 20mg daily||Not licensed|
No antidote available if rapid reversal required
(e.g. for emergency surgery, catastrophic bleeding).
In specialist centres, certain specialist blood products may be given.
No dietary restrictions are required.
|Costs (for AF)||£920/y which is mainly drug costs (DTB)||£705/y (drug costs only) (NICE)||Awaiting NICE approval and costings.|
Warfarin costs around £426/y which includes all NHS costs such as drug, phlebotomy and lab time, but not patient costs (DTB).
No monitoring of coagulation needed.
|Check eGFR before starting then annually if: ≥ 75y, weight < 50kg or eGFR 30-50.|
|Renal/liver disease (from BNF)||Renal:Avoid if eGFR <30.If eGFR 30-60, reduce to 150mg once daily.Liver:|
Avoid in severe liver disease especially if coagulopathy.
|Renal:Avoid if eGFR <15.Caution if eGFR 15-60.Liver:|
May be used in moderate hepatic impairment as long as no coagulopathy.
|Renal:Avoid if eGFR <15.Caution if eGFR 15-29.Liver:|
Avoid in severe impairment and if coagulopathy associated with hepatic disease.
|Common side effects (see BNF for details)||Nausea, diarrhoea, dyspepsia, and abdominal pain||Nausea and abnormal LFTs.||Nausea.|
Anaemia/bleeding are recognised side effects.
Many! Check with BNF before prescribing and seek advice if needed!
Do not use with NSAIDs (because of increased bleeding risk).
- Those at high risk of stroke in whom INR monitoring is difficult
- Those with poor anticoagulation control
- Those at high risk of drug interactions.