Healthcare workers have been aware of novel oral anticoagulants (NOACs) for some time. The first NOACs to be approved for registration in Australia were dabigatran and rivaroxaban in 2008, however they were not widely used until their listing on the Pharmaceutical Benefits Scheme (PBS). In November 2009 dabigatran was recommended for listing on the PBS for the prevention of venous thromboembolism (VTE) in patients undergoing total hip or total knee replacement, and was subsequently listed on 1st April 2010. Even then, use of dabigatran was not widespread due to the limited scope for subsidised use.
Between 2011 and 2013, the PBS listings of NOACs expanded to allow for indications relating to deep vein thrombosis (DVT), pulmonary embolism (PE) and atrial fibrillation (AF). It should be noted however, that at the time, the range of approved PBS indications varied between the brands of NOAC, although they now all have similar approved indications. Since these inclusions, the use of NOACs are now commonplace.
Whilst nurses typically display a good understanding of the use of aspirin and warfarin within the hospital setting, many may express a desire to learn more about NOACs; the latest “wonder-drugs”. Consultation with nursing staff within one of HPS Pharmacies’ client hospitals determined they desire relevant information for their professional development, incorporating a brief overview of the class, how they work, dosage information, and precautions surrounding surgery, monitoring, and reversal. Information on how to safely change a patient’s therapy to, from, or between NOACs was also communicated as being useful.
Consequently, the information in Table 1 has been compiled as a guide for nursing staff.
Table 1. Novel Oral Anticoagulants – A Guide to Dosing
|
Dabigatran |
Rivaroxaban |
Apixaban |
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| Standard Indication Doses | Take with food and a glass of water at the same time each day. Do not open the capsule or chew the pellets. | Take with food at the same time each day | Take at the same time each day | |||||||
| Prevention of VTE following knee or hip replacement | ||||||||||
| 110mg within 1-4 hours of surgery, then 220mg once daily for 10 days following knee replacement, or 28-35 days following hip replacement | 10mg once daily, commencing 6–10 hours after surgery, for 14 days following knee replacement, or 35 days following hip replacement | 2.5mg twice daily, commencing 12–24 hours after surgery, for 10–14 days following knee replacement, or 32–38 days following hip replacement | ||||||||
| Treatment and/or prevention of acute VTE | ||||||||||
| N/A | 15mg twice daily for three weeks, then 20mg once daily | N/A | ||||||||
| Prevention of emboli in AF | ||||||||||
| 150mg twice a day | 20mg once daily | 5mg twice a day | ||||||||
| Dose Modifications | ||||||||||
| Liver Disease (liver enzymes >2 x ULN) |
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| Contraindicated | No advice | No advice | ||||||||
| Renal Failure (renal function 30-50 mL/min) |
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| Reduce dose | Reduce dose for prevention of emboli in AF. Seek advice if CrCl<30mL/min. |
Complex. Seek advice if:
|
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| Surgery | ||||||||||
| Cease 2-4 days prior to surgery (longer with renal impairment) | Cease 1-2 days prior to surgery (or 4-5 days for complete haemostasis) | Cease at least 48 hours prior to surgery | ||||||||
| Switching Anticoagulants | ||||||||||
| Switching from NOAC to parenteral anticoagulant | ||||||||||
|
Commence at the time of the next scheduled dose | Commence at the time of the next scheduled dose | ||||||||
| Switching from NOAC to Warfarin | ||||||||||
Cease NOAC after:
|
Limited data. Add standard warfarin dose to NOAC for two days, then adjust warfarin until INR >2, then cease NOAC. (Measure INR >24 hours after any rivaroxaban dose). |
Add standard warfarin dose to NOAC for two days, then adjust warfarin until INR >2, then cease NOAC. (Measure INR prior to next apixaban dose). |
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| Switching from parenteral anticoagulant to NOAC | ||||||||||
| Commence within two hours prior to the next scheduled dose | Commence within two hours prior to the next scheduled dose | Commence at the time of the next scheduled dose | ||||||||
| Switching from Warfarin to NOAC | ||||||||||
| Commence when: INR <2 |
Commence when:
|
Commence when: INR <2 |
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There will be more to learn about NOACs as their usage in practice becomes more prevalent. Therefore, it is important that product information is kept up-to-date, and that education of both nursing and pharmacy staff is reviewed frequently. It is anticipated these new anticoagulants can assist patients to achieve a better quality of life while anticoagulated.
For further information, please speak with your local HPS Pharmacies Pharmacist.
References:
- Rossi S (ed). Australian Medicines Handbook. Adelaide: Australian Medicines Handbook Pty Ltd; 2015.
- Pradaxa® (dabigatran) Australian approved product information. North Ryde: Boehringer Ingelheim Pty Ltd. Approved 24 November 2008, amended 28 April 2015.
- Xarelto® (rivaroxaban) Australian approved product information. Pymble: Bayer Australia Ltd. Approved 24 November 2008, amended 15 January 2015.
- Eliquis® (apixaban) Australian approved product information. Mulgrave: Bristol-Myers Squibb Australia Pty Ltd. Approved 21 July 2011, amended 15 May 2015.