What is the role of vitamin K, dicynone (etamsylate), and tranexamic acid in managing gastrointestinal (GI) bleeding?

Management of Gastrointestinal Bleeding: Role of Vitamin K, Dicynone, and Tranexamic Acid

Tranexamic acid is not recommended for routine use in gastrointestinal bleeding as it shows no mortality benefit and increases the risk of thromboembolic events. 1

Vitamin K in GI Bleeding

For Patients on Warfarin

• Recommended for life-threatening bleeding with INR above 2.5
• Should be administered as low-dose vitamin K plus 4-factor prothrombin complex concentrate (PCC) 2
• Higher doses of vitamin K (>5 mg) are not recommended in patients with high thromboembolic risk 2

For Patients on Direct Oral Anticoagulants (DOACs)

• Vitamin K is ineffective and not recommended for treatment of bleeding associated with DOACs 2
• Instead, specific reversal agents should be considered:
  • Idarucizumab for dabigatran-related life-threatening bleeding 2
  • Andexanet for anti-factor Xa inhibitor-related life-threatening bleeding 2

Tranexamic Acid in GI Bleeding

Upper GI Bleeding

• Not recommended for routine use in upper GI bleeding
• The HALT-IT trial (n=12,009) showed:
  • No reduction in mortality (RR 0.99,95% CI 0.82-1.18)
  • Nearly 2-fold increase in venous thromboembolic events, particularly in patients with liver disease 2, 1

Lower GI Bleeding

• Not effective in reducing blood transfusion requirements in lower GI bleeding 3
• Current guidelines suggest confining use of tranexamic acid in acute LGIB to clinical trials 2

Special Consideration: Hereditary Hemorrhagic Telangiectasia

• Oral tranexamic acid may be considered for epistaxis that doesn't respond to moisturizing topical therapies
• Can be used for mild GI bleeding in HHT patients, though evidence of effectiveness is limited 2

Dicynone (Etamsylate)

• Not mentioned in current major guidelines for management of GI bleeding
• No evidence supporting its use in acute GI bleeding was found in the provided guidelines

Management Algorithm for GI Bleeding in Patients on Antithrombotic Agents

1. For patients on warfarin:

   • Withhold warfarin to facilitate hemostasis 2
   • For life-threatening bleeding with INR >2.5: Administer 4-factor PCC plus low-dose vitamin K 2
   • Resume warfarin once adequate hemostasis is achieved 2

2. For patients on DOACs:

   • Withhold DOAC to facilitate hemostasis 2
   • For life-threatening bleeding:
     • If last dose taken within 3 hours: Consider activated charcoal 2
     • For dabigatran: Use idarucizumab 2
     • For Xa inhibitors: Consider andexanet 2
   • Resume DOAC after adequate hemostasis is achieved, typically within 7 days 2

3. For patients on dual antiplatelet therapy (DAPT):

   • Do not withhold both antiplatelet agents due to high risk of stent thrombosis 2
   • Continue aspirin and withhold P2Y12 inhibitor (e.g., clopidogrel) 2
   • Resume P2Y12 inhibitor preferably within 5 days after endoscopic hemostasis 2

Important Caveats and Pitfalls

• Portal hypertension-related bleeding: Focus on portal pressure-lowering measures rather than hemostatic agents 2
• Tranexamic acid risks: Increased risk of venous thromboembolism, particularly in patients with liver disease 2, 1
• Vitamin K limitations: Ineffective for DOAC-related bleeding and should be used at low doses in patients with high thromboembolic risk 2
• Timing of antithrombotic resumption: Critical to balance risks of rebleeding versus thrombosis; generally safe to restart within 5-7 days after achieving hemostasis 2

While some older and smaller studies suggested benefits of tranexamic acid in GI bleeding 4, 5, the most recent and largest randomized controlled trial (HALT-IT) definitively showed no mortality benefit with increased thrombotic risk 1, which has been incorporated into current guidelines 2, 6.