How to check a DOAC dose in primary care (apixaban, rivaroxaban, edoxaban)
Medicine in Practice · 14 July 2026
DOAC anticoagulation apixaban high-risk drugs prescribing safety medication review
Direct oral anticoagulants (DOACs) are among the highest-volume high-risk medicines you will meet in general practice, and a wrong dose is one of the most common — and most consequential — prescribing errors. Checking a DOAC dose is a core skill for any pharmacist running high-risk drug monitoring or a structured medication review. This guide walks through how to check apixaban, rivaroxaban and edoxaban doses systematically, and the traps to avoid.
Everything below is a general framework for reviewing prescribing. Always confirm the specifics against the current SPC, the BNF and your local anticoagulation guidance for the individual patient before making any change.
Key takeaways
- A DOAC dose is decided by three things together: the indication, the patient's renal function, and drug-specific dose-reduction criteria.
- The commonest error is a reduced dose used for the wrong reason, or a treatment dose left in place when reduction criteria are met.
- Renal function must be current and calculated correctly — DOAC dosing uses creatinine clearance (Cockcroft-Gault), not eGFR.
- Apixaban's atrial fibrillation reduced dose depends on meeting two of three criteria: age 80 or over, weight 60 kg or under, creatinine 133 micromol/L or more.
- A dose check is a prompt to verify against the SPC and local guidance, document your reasoning, and safety-net — not a substitute for clinical judgement.
Why DOAC dosing goes wrong
Unlike warfarin, DOACs have no routine INR to catch an out-of-range dose, so an incorrect dose can persist unnoticed for months. Doses differ by indication (atrial fibrillation vs treatment of venous thromboembolism vs extended VTE prevention), and each drug has its own reduction rules. It is easy for a treatment-dose regimen to be continued when the patient has since met dose-reduction criteria, or for a reduced dose to be started without a documented reason.
Your job on review is to reconstruct the reasoning: which indication, what is the current renal function, and do the drug-specific criteria apply? If any of those cannot be answered from the record, that is the finding.
The three things that set the dose
1. Indication. Confirm exactly what the DOAC is for. Non-valvular atrial fibrillation (stroke prevention) and treatment of deep-vein thrombosis or pulmonary embolism use different regimens, and VTE treatment often starts with a higher loading period before a maintenance dose.
2. Renal function. DOAC dose decisions use creatinine clearance estimated by the Cockcroft-Gault equation, which needs the patient's age, weight and serum creatinine. The eGFR reported automatically by the lab is body-surface-area adjusted and is not the same number — relying on it can mis-dose light or elderly patients. Check that the renal result is recent, especially in older or unwell patients.
3. Drug-specific reduction criteria. Each DOAC has its own rules, below. A dose reduction should map to a documented reason.
Checking an apixaban dose
For atrial fibrillation, the standard apixaban dose is 5 mg twice daily. It reduces to 2.5 mg twice daily if the patient meets at least two of these three criteria: age 80 years or over, body weight 60 kg or under, or serum creatinine 133 micromol/L or more. A very common error is a 2.5 mg dose in a patient who meets only one criterion, or a 5 mg dose where two are met.
For treatment of VTE the regimen is different again (an initial higher-dose period followed by maintenance), so always confirm which indication you are dosing for before comparing against the AF rule.
Checking rivaroxaban and edoxaban
Rivaroxaban for atrial fibrillation is usually 20 mg once daily with food, reduced to 15 mg once daily where renal function is impaired within the licensed range. Taking it with food matters for absorption at the 15 mg and 20 mg strengths and is worth checking in the counselling record.
Edoxaban for atrial fibrillation is usually 60 mg once daily, reduced to 30 mg once daily for impaired renal function within the licensed range, low body weight (60 kg or under), or use of certain interacting drugs. Edoxaban also has an upper renal limit above which it is not recommended, so a high creatinine clearance is as relevant as a low one.
Against every one of these, the method is the same: current weight, current creatinine, correct clearance calculation, then match to the SPC criteria and record the reasoning.
Renal function and ongoing monitoring
Renal function is not static. A sensible pattern is to recheck at least annually, and sooner if the patient is elderly, frail, has a clearance approaching a dose threshold, or has an intercurrent illness (dehydration, acute kidney injury, new interacting drugs). A DOAC dose that was right last year can be wrong today if weight or renal function has changed. This is exactly the kind of recall-and-review workflow covered in high-risk drug monitoring in primary care.
Common errors to catch on review
The recurring problems are: a reduced dose with no documented reason; a treatment dose continued after the patient met reduction criteria; eGFR used instead of creatinine clearance; an out-of-date creatinine; a missed drug interaction; and a DOAC continued at a clearance below (or above) the licensed range for that drug. Each of these is a legitimate finding to raise, document and, where needed, escalate to the prescriber.
How Medicine in Practice helps: our training builds the medication-review, monitoring and clinical-reasoning skills that make DOAC checks second nature, with realistic cases so you practise the decision, not just read the rule.
Frequently asked questions
Do DOACs use eGFR or creatinine clearance for dosing?
DOAC dose decisions use creatinine clearance estimated with the Cockcroft-Gault equation, which needs age, weight and serum creatinine. The automatically reported eGFR is calculated differently and is not interchangeable, so using it can mis-dose light or elderly patients.
What are the apixaban reduced-dose criteria for atrial fibrillation?
For atrial fibrillation, apixaban reduces from 5 mg twice daily to 2.5 mg twice daily when the patient meets at least two of: age 80 years or over, weight 60 kg or under, or serum creatinine 133 micromol/L or more. Always confirm against the current SPC.
How often should renal function be checked for a patient on a DOAC?
At least annually is a common minimum, and more often for older, frail or acutely unwell patients, those with a clearance near a dose threshold, or after any change in weight or interacting medicines. Follow your local anticoagulation guidance.
Is the DOAC dose different for atrial fibrillation and VTE treatment?
Yes. Stroke prevention in atrial fibrillation and treatment of venous thromboembolism use different regimens, and VTE treatment often begins with a higher-dose period. Always confirm which indication you are dosing for before applying dose rules.
Does rivaroxaban need to be taken with food?
The 15 mg and 20 mg strengths of rivaroxaban should be taken with food to ensure reliable absorption. It is worth confirming this has been counselled and recorded, as taking it without food can reduce the effect at these strengths.