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Direct Oral Anticoagulant / AF Pregnancy: Contraindicated — animal data shows reproductive toxicity; limited human data. Use LMWH in pregnancy.

Dabigatran (AF / VTE)

Brand names: Pradaxa

Adult dose

Dose: AF stroke prevention: 150 mg twice daily (110 mg BD if age >=80, or age 75-79 with high bleeding risk, or on verapamil). VTE treatment: 150 mg BD after 5-10 days of parenteral anticoagulation.
Route: Oral
Frequency: Twice daily
Max: 150 mg BD
Direct thrombin (factor IIa) inhibitor. RE-LY trial. Requires dose reduction based on age, renal function, body weight. Swallow capsule whole — do NOT crush/open (significantly increases absorption). Store in original blister pack (moisture-sensitive).

Paediatric dose

Route: Oral
Licensed for VTE treatment/prevention in children from birth — weight-based dosing. Specialist paediatric haematology guidance essential.

Dose adjustments

Renal

eGFR 30-49: 110 mg BD for AF (150 mg BD still licensed but higher bleeding risk). eGFR 15-29: AVOID for AF. eGFR <30: AVOID. Dabigatran is 80% renally cleared — most renal-sensitive of all DOACs.

Hepatic

Avoid in hepatic disease with coagulopathy or active liver disease

Clinical pearls

  • RE-LY trial (Connolly et al. NEJM 2009): dabigatran 110 mg BD (non-inferior to warfarin for stroke; less bleeding) vs 150 mg BD (superior to warfarin for stroke; similar major bleeding). First DOAC trial to show DOAC non-inferior/superior to warfarin in AF.
  • Mechanical valve contraindication: RE-ALIGN trial — dabigatran in mechanical heart valve replacement caused significantly more thromboembolic events and bleeding than warfarin. All DOACs are CONTRAINDICATED in mechanical prosthetic valves and significant mitral stenosis.
  • Dyspepsia management: the tartaric acid excipient in dabigatran capsules causes gastric irritation. Take with a full glass of water or with food. PPI/antacid can help. Do NOT open capsules — alters pharmacokinetics dramatically.
  • Idarucizumab (Praxbind) reversal: specific antidote for dabigatran — 5 g IV in two 2.5 g boluses. REVERSE-AD trial confirmed reversal in <5 minutes. Available in all UK emergency departments.
  • Most renally excreted DOAC: dabigatran 80% renal clearance vs rivaroxaban 33%, apixaban 27%, edoxaban 50%. In deteriorating renal function, switch to apixaban (least renally excreted) or to warfarin.

Contraindications

  • eGFR <30 for AF indication
  • Active significant bleeding
  • Prosthetic heart valve (RE-ALIGN trial showed inferiority to warfarin — DOAC contraindicated with mechanical valves)
  • Moderate-severe hepatic impairment
  • Concomitant strong P-gp inhibitors (ketoconazole, cyclosporin, itraconazole, dronedarone — markedly increase levels)

Side effects

  • Bleeding (GI bleeding higher than warfarin; intracranial bleeding lower than warfarin)
  • Dyspepsia (common — take with food or antacid; due to tartaric acid in capsule)
  • Nausea
  • Hepatotoxicity (elevated LFTs)

Interactions

  • Strong P-gp inhibitors (ketoconazole, cyclosporin, itraconazole, dronedarone) — markedly increase dabigatran levels; CONTRAINDICATED
  • Strong P-gp inducers (rifampicin, carbamazepine, phenytoin, St John's Wort) — significantly reduce levels; avoid
  • Verapamil — increases dabigatran levels 12-20%; give verapamil >=2h after dabigatran and use 110 mg BD dose
  • Aspirin/NSAIDs — additive bleeding risk

Monitoring

  • eGFR at baseline and annually (every 6 months if eGFR 30-60)
  • Signs of bleeding
  • LFTs (baseline)
  • Adherence (twice-daily dosing — more frequent missed doses than OD DOACs)

Reference: BNFc; BNF 90; RE-LY Trial (Connolly et al. NEJM 2009); RE-ALIGN Trial; REVERSE-AD Trial; NICE TA249; SPC Pradaxa. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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