Ten top tips: Reviewing patients on established DOAC treatment

Top tips on reviewing patients on established DOAC treatment.

1. Confirm indication. The two licensed indications for DOAC are non-valvular atrial fibrillation and venous thromboembolism.  All other indications should have been confirmed by a specialist.  DOAC are contraindicated in the presence of moderate-to-severe mitral stenosis, metallic valves, anti-phospholipid syndrome and severe renal impairment (CKD5/creatinine clearance <15 ml/min). The Medicines and Health products Regulatory Agency (MHRA) and the British National Formulary (BNF) should be consulted for up to date information.   
2. Confirm duration. Treatment in the setting of NVAF is usually lifelong, unless contraindications or bleeding complications develop, at which point a further review is required. If stopped, clear documentation is required with plans for further review.  Where there is an absolute contraindication, there should be documented confirmation that no further anticoagulation is intended. In the setting of VTE, the diagnosing specialist should specify recommended duration. Provoked VTE usually requires time-limited treatment. This is clarified in the NICE Clinical Knowledge Summary (2020). 
3. Confirm correct dose. Several audits have demonstrated a high rate of incorrect DOAC dose for NVAF.  The standard dose of DOAC should be used by default, with recourse to a reduced dose only where criteria for reduced dose are met in line with the advice in the BNF.  Dose reduction with the perception of high bleeding risk is not associated with any benefit. Renal function for dose choice should involve calculation of Cockroft-Gault creatinine clearance (CG CrCl).  Inbuilt clinical tools within the practice software such as SystmONE can be used to calculate the renal function and saved automatically into the patient notes. However, an updated blood test and weight is required for an accurate calculation.  NICE guidance and the SmPC for all DOACs are clear that dosing should be based on CG CrCL and not eGFR. Papers have reported significant under and over dosing errors by using eGFR. To ensure the patient is on the correct dose, consult the BNF.
4. Drug interaction. A standard medication check should be undertaken to ensure no drugs with significant interaction have been started inadvertently, and in some cases, a dose reduction is indicated. Consider possible interactions, and check if necessary, with the BNF.
5. Clinical assessments (including blood test). A blood test is required at each review to include FBC, U&E, LFT (with CG CrCl calculation, needs current weight). Ideally, this should be scheduled to happen a few days before so that the clinical review can be completed in one sitting with results in hand. Local guidelines should be developed in accordance with the national guidelines e.g. Leicestershire Medicines Strategy Group Guidelines (2020).  
6. Bleeding & bleeding risk. Patients should be asked about any bleeding at reviews. For isolated minor self-resolving bleeding, no action is required. One or two doses can be skipped to allow the bleeding to settle. If recurrent, medical attention should be sought to identify an underlying cause. Immediate medical attention and hospital assessment is indicated in the setting of significant bleeding.
7. Frequency of monitoring. A standard minimum annual DOAC review is required, with more frequent review in the setting of increasing renal impairment and higher bleeding risk. Local protocols in line with the NICE guidelines can be used such as LMSG (2020) for Direct Oral Anticoagulants as a guide to set the review recalls. 
8. Do I need help? Where there is uncertainty about any of the aspects of clinical review, a consultation should be undertaken with a more experienced clinician and documented e.g. GP, advice from hospital anticoagulation team, Haematologist etc.  
9. Patient information needs. The relative ease of use of DOAC (versus warfarin) and stable dosing may falsely reassure patients and clinicians.  However, DOAC are potent “blood thinners” which increase bleeding risk, and care must be taken to avoid injuries, manage any bleeding appropriately, and patients should be provided with an anticoagulant alert card to carry at all times. A practice phone number should be provided for queries. This is the same as the warfarin care and all prescribers should be giving this to the patient.
10. Outcome & follow up date. DOAC review should end with a definitive outcome e.g. continue DOAC, change dose, change anticoagulant, stop anticoagulant temporarily (and review after specified time period), stop anticoagulant permanently.  The next follow up date should be confirmed before review is completed. There should also be a system in place which acts as safety net to recall patients due for reviews and identify pending reviews.  

Below is a proposed sample checklist for DOAC review.

This can be adapted within a local practice protocol which can be used in conjunction with patient’s electronic notes or a register database for patients on a DOAC such as INR STAR (2020).  

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