01Purpose and principlesWhat the treatment does and how it fits into care.
Apixaban, rivaroxaban and edoxaban inhibit factor Xa; dabigatran inhibits thrombin. Their rapid onset removes routine bridging for most uses but makes missed doses clinically important. There is no single DOAC dose. Acute VTE, extended VTE prevention, atrial fibrillation and post-operative prophylaxis each use distinct schedules. Renal clearance is greatest for dabigatran, but kidney function matters to all four. Establish actual weight and Cockcroft–Gault creatinine clearance, liver function, FBC, pregnancy status, interacting drugs and adherence before prescribing. Reassess after acute kidney injury, dehydration or a major weight change rather than waiting for annual review.
Bleeding assessment begins with drug exposure. Record the exact medicine, tablet strength, last dose time, usual timing, adherence, renal trajectory and P-glycoprotein or CYP3A4 inhibitors. PT and APTT are qualitative and reagent dependent: a normal result cannot clear apixaban or rivaroxaban, and an elevated result cannot quantify effect. A normal thrombin time makes a substantial dabigatran level unlikely; diluted thrombin time or ecarin assay can quantify dabigatran, and a drug-calibrated anti-Xa assay can quantify apixaban or rivaroxaban. Do not delay life-saving source control while waiting for a specialist level.
All severe bleeding needs the same foundation: stop anticoagulant and unnecessary antiplatelets, ABCDE resuscitation, major-haemorrhage support when required, local compression or endoscopic, interventional or surgical source control, temperature and calcium correction and targeted blood components. Tranexamic acid follows the bleeding indication, not the mere presence of a DOAC. In trauma it is time critical under the trauma protocol; routine use in gastrointestinal bleeding is not supported. Platelets do not reverse a DOAC but may be needed for thrombocytopenia or clinically relevant antiplatelet exposure.
Idarucizumab is a monoclonal antibody fragment that binds dabigatran. Give 5 g IV as two consecutive 2.5 g/50 mL doses for life-threatening or uncontrolled bleeding or urgent procedures. Rebound dabigatran can occur, especially with renal impairment or overdose; recheck clinical bleeding and coagulation or drug levels and a second 5 g course may be considered only if clinically relevant reappearance accompanies recurrent bleeding or a second urgent procedure. Dabigatran can usually restart after 24 hours when haemostasis is secure and treatment remains appropriate.
Andexanet is a modified factor Xa decoy for apixaban and rivaroxaban. Low dose is a 400 mg IV bolus followed by 4 mg/min for 120 minutes; high dose is an 800 mg bolus followed by 8 mg/min for 120 minutes. Selection depends on the last apixaban or rivaroxaban dose and whether it was taken less than 8 hours ago or the time is unknown. It is not licensed for edoxaban or LMWH, is not established as pretreatment for urgent surgery, can interfere with heparin anticoagulation and carries significant thrombosis risk. UK access must follow current NICE and local policy.
Restart is part of reversal care. Confirm source control, haemoglobin stability, renal recovery and whether the original dose remains correct. Balance rebleeding site against untreated thrombosis: intracranial bleeding usually needs a specialist delayed plan, whereas a controlled extracranial lesion may permit earlier resumption. Use mechanical prophylaxis while pharmacological treatment is unsafe where appropriate. Do not automatically replace a DOAC with low-dose LMWH; choose timing and intensity from indication, time since thrombosis, AF stroke risk, cancer, mobility and procedural haemostasis.
Key points
- DOAC doses are indication specific: never transfer an atrial-fibrillation reduction rule to acute VTE or mistake an extended-prevention dose for initial treatment.
- Use Cockcroft–Gault creatinine clearance, not unadjusted laboratory eGFR, and repeat it during acute illness because drug accumulation can change within hours.
- Apixaban and rivaroxaban start acute VTE with intensified oral regimens; dabigatran and edoxaban require at least 5 days of therapeutic parenteral anticoagulation first.
- A normal PT or APTT does not reliably exclude a clinically relevant apixaban or rivaroxaban concentration; thrombin time is highly sensitive to dabigatran but is not quantitative.
- Idarucizumab 5 g IV is the specific first-line reversal for dabigatran when bleeding is life-threatening or uncontrolled or urgent surgery cannot wait.
- Andexanet alfa is licensed for adult apixaban- or rivaroxaban-associated life-threatening or uncontrolled bleeding; dose depends on the factor Xa inhibitor dose and time since ingestion.
- NICE TA697 recommends andexanet within its defined commissioned population for uncontrolled or life-threatening gastrointestinal bleeding; other sites require current national and local specialist policy.
- Four-factor PCC has no licensed DOAC-neutralising action but may be used off label for severe factor-Xa-inhibitor bleeding when specific reversal is unavailable or inappropriate under a haematology protocol.
- Activated charcoal can reduce absorption after a recent ingestion when the airway is protected; dialysis can remove dabigatran but not highly protein-bound factor Xa inhibitors.
- After haemostasis, reassess early restart: unnecessary prolonged interruption exposes the patient to recurrent VTE, cardioembolic stroke or valve-related thrombosis.
02Indications, selection and cautionsWho may benefit, who needs urgent treatment and important alternatives.
A recent dose, impaired renal clearance, overdose or strong interaction makes active anticoagulant effect more likely and may change procedural timing or reversal.
Small-volume intracranial, spinal, pericardial or airway bleeding can be fatal without a large haemoglobin fall or shock.
Identify factor Xa inhibitor versus dabigatran because assays, dialysability and licensed reversal agents are different.
Continued haematemesis, expanding compartment, neurological deterioration or transfusion requirement indicates that drug withdrawal alone is inadequate.
New chest pain, limb ischaemia, neurological deficit or catheter thrombosis after reversal requires urgent assessment without assuming recurrent bleeding.
03Assessment before treatmentTests and checks that guide safe selection.
Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.
- 01
First-line: exposure, FBC and organ profileFirst stepFirst line - Why
- Estimate residual effect, blood loss and clearance capacity.
- Interpretation and limitations
- Record exact last dose and calculate Cockcroft–Gault CrCl. Serial haemoglobin, platelets, renal and liver results are more informative than one normal measurement during early haemorrhage.
- 02
PT, APTT, fibrinogen and thrombin time - Why
- Detect a broader coagulopathy and gain limited qualitative information.
- Interpretation and limitations
- Normal PT/APTT cannot exclude apixaban or rivaroxaban. A normal thrombin time argues strongly against substantial dabigatran; abnormal results may also reflect DIC, liver disease or factor deficiency.
- 03
Confirmatory: calibrated DOAC assayConfirmatory - Why
- Quantify residual drug when the result can alter reversal or urgent procedural timing.
- Interpretation and limitations
- Use drug-calibrated anti-Xa for apixaban or rivaroxaban and diluted thrombin time or ecarin-based testing for dabigatran; interpret concentration with last-dose timing and local thresholds.
- 04
Site-defining imaging or endoscopy - Why
- Locate and control the anatomical cause rather than relying on pharmacological reversal.
- Interpretation and limitations
- Urgent CT head, CT angiography, endoscopy, interventional radiology or operative assessment follows physiology and suspected site; do not postpone it for a level that is unavailable quickly.
- 05
Post-reversal clinical and laboratory review - Why
- Detect rebound anticoagulation, treatment failure, transfusion need and thrombosis.
- Interpretation and limitations
- Follow haemodynamics, neurological status, haemoglobin and relevant assay. Commercial anti-Xa assays can be misleading after andexanet and treatment response is primarily clinical.
04Treatment approachPreparation, options, escalation and aftercare.
01Dabigatran emergencyUse specific neutralisationFirst stepDabigatran exposure accompanies life-threatening or uncontrolled bleeding or surgery that cannot safely wait.+
- 1Stop dabigatran, resuscitate, control the source and record last dose, renal function, thrombin time and drug level if rapidly available.
- 2DefinitiveGive idarucizumab 5 g IV as two consecutive 2.5 g doses while definitive haemostasis proceeds.
- 3Monitor for recurrent bleeding or rebound, then reassess renal function, correct dose and restart when haemostasis and thrombotic risk permit.
02Factor Xa emergencyMatch reversal to indication and policyRecent apixaban or rivaroxaban accompanies life-threatening or uncontrolled bleeding.+
- 1Stabilise, stop the agent, establish dose and time, renal function and bleed site, and involve haematology and the source-control specialty immediately.
- 2Use andexanet when its licensed indication and current NICE or local commissioning criteria are met; otherwise follow the specialist PCC or supportive protocol.
- 3Watch for thrombosis and haemostatic failure and make a documented anticoagulation restart decision after source control.
03Urgent procedureDetermine whether surgery can waitAn invasive procedure is needed before ordinary DOAC clearance is assured.+
- 1Define procedure urgency and bleeding consequence, last dose, CrCl, interacting drugs and a calibrated level when it will return in time.
- 2Delay for natural clearance when safe; use idarucizumab for qualifying dabigatran exposure, while factor-Xa reversal before surgery requires specialist policy because andexanet is not established for this use.
- 3Proceed with surgical haemostasis, then use a procedure-specific restart and thromboprophylaxis plan.
04Non-major bleedingHold briefly and treat the lesionBleeding is clinically relevant but not at a critical site, haemodynamically significant or uncontrolled.+
- 1Confirm drug, phase, last dose, renal function, haemoglobin and contributing antiplatelets or NSAIDs.
- 2Use local haemostasis and omit or delay the next dose when appropriate; specific reversal is usually unnecessary.
- 3EscalationInvestigate the source, correct dosing or interactions and restart promptly once safe, with escalation if bleeding progresses.
05Regimens, contraindications and interactionsTreatment details and the circumstances that modify them.
Idarucizumab
Give 5 g intravenously as two consecutive 2.5 g/50 mL infusions over 5–10 minutes each or bolus injections for dabigatran-associated life-threatening or uncontrolled bleeding or urgent surgery.It does not reverse factor Xa inhibitors or other coagulopathy. Monitor for rebound in renal failure or overdose and for thrombosis after reversal; consider another 5 g only for supported recurrent-effect scenarios with specialist input.
Andexanet alfa low dose
Give 400 mg intravenously at about 30 mg/min, immediately followed by 4 mg/min for 120 minutes when the last apixaban or rivaroxaban dose and timing meet the low-dose table.Use the SmPC dose table rather than guessing from bleed severity. Thromboembolism, myocardial infarction, stroke and cardiac arrest occur; it can cause heparin unresponsiveness and is not licensed for edoxaban, LMWH or routine urgent-surgery pretreatment.
Andexanet alfa high dose
Give 800 mg intravenously at about 30 mg/min, immediately followed by 8 mg/min for 120 minutes when the last factor Xa inhibitor dose is above the low-dose threshold and was within 8 hours or its timing is unknown.Confirm agent, last dose and time against the SmPC. Use only within national and local policy, pursue definitive haemostasis simultaneously and establish a post-reversal thrombosis-monitoring and anticoagulation-restart plan.
Four-factor PCC for factor Xa bleeding
When specific reversal is unavailable or inappropriate, use the exact off-label product and weight-based dose in the local major-haemorrhage protocol; many UK protocols use 25–50 IU factor IX/kg with a defined maximum after senior haematology approval.Evidence and dosing are less certain than licensed reversal and thrombosis risk is substantial. It does not replace source control, should not be given for a laboratory abnormality alone and should not be routinely redosed.
Activated charcoal
Consider a single oral or enteral dose under toxicology or emergency guidance soon after a clinically important ingestion, commonly within 2 hours, only when the airway is protected and aspiration or obstruction risk is acceptable.It does not remove absorbed drug and is not a substitute for resuscitation or reversal. Avoid with an unprotected airway, ileus, gastrointestinal perforation or when administration delays definitive care.
06Complications, monitoring and follow-upAdverse effects, response and longer-term review.
- Before and during routine DOAC therapy monitor FBC, Cockcroft–Gault CrCl, liver function, weight, adherence, bleeding, thrombosis and interacting medicines at an interval matched to age and organ stability.
- During bleeding, trend haemodynamics, neurological status, haemoglobin, platelets, fibrinogen, renal function and transfusion need; early haemoglobin can underestimate acute loss.
- After idarucizumab, assess clinical haemostasis and recurrent dabigatran effect, particularly after overdose or severe renal impairment; use thrombin time or a quantitative assay when it changes action.
- After andexanet or PCC, monitor closely for arterial and venous thrombosis, myocardial ischaemia and stroke as well as recurrent bleeding; plan thromboprophylaxis and therapeutic restart explicitly.
- At restart, confirm source control, current renal function and the correct indication-specific dose; remove unnecessary antiplatelets and arrange follow-up of the bleeding lesion.
07Special situationsVariants, exceptions and circumstances that change the usual approach.
Routine tests can reassure falsely
PT sensitivity to apixaban and rivaroxaban varies by reagent. Clinical exposure history and a calibrated assay are more useful than declaring a normal PT safe.
Reversal is not source control
A decoy or binding antibody cannot ligate an artery, decompress a compartment or treat a tumour. Pharmacology and anatomical haemostasis must occur in parallel.
Andexanet changes heparin response
Andexanet binds heparin-activated antithrombin-related activity and can produce heparin unresponsiveness, a major issue if urgent cardiac or vascular surgery needs heparinisation.
Dabigatran can rebound
A large extravascular reservoir can redistribute after idarucizumab, particularly in renal failure. Recurrent bleeding plus renewed assay abnormality—not a number alone—supports specialist redosing.
Interruption carries harm
Reversal patients often had a strong indication for anticoagulation. Daily reassessment prevents a controlled bleed becoming an avoidable embolic event.
08Common pitfallsFrequent interpretation and management errors.
- 01
Do not use normal PT or APTT to exclude factor Xa inhibitor effect before neurosurgery, thrombolysis or major reversal decisions.
- 02
Do not give idarucizumab for apixaban, rivaroxaban or edoxaban; its binding is specific to dabigatran.
- 03
Do not use andexanet for edoxaban, LMWH or routine pre-operative reversal outside evidence and policy simply because all inhibit factor Xa.
- 04
Do not delay endoscopy, embolisation, surgery or pressure while waiting for a reversal infusion to finish.
- 05
Do not give PCC to every DOAC-treated patient with bruising or a raised PT; reserve prohaemostatic treatment for severe clinical bleeding under protocol.
- 06
Do not forget to restart or formally discontinue anticoagulation after reversal; write the decision, responsible team and review date.