Is Eliquis (apixaban) suitable for treating heparin-induced thrombocytopenia (HIT)?

Apixaban is Not Recommended for Heparin-Induced Thrombocytopenia (HIT)

Apixaban (Eliquis) is not currently recommended as a first-line treatment for heparin-induced thrombocytopenia (HIT) according to current guidelines, which recommend parenteral non-heparin anticoagulants as the initial therapy of choice. 1

Initial Management of HIT

When HIT is suspected or confirmed:

1. Immediate discontinuation of all heparin products (including heparin flushes and heparin-coated catheters) 1

2. First-line treatment options (in order of preference):

   • Argatroban: Preferred in patients with renal dysfunction (initial dose 0.5-2 μg/kg/min IV) 2
   • Bivalirudin: Particularly useful for patients requiring urgent cardiac surgery 2
   • Danaparoid: Not available in many countries; avoid in severe renal failure 2

3. Fondaparinux: A reasonable option for clinically stable patients at average bleeding risk 1

Role of Direct Oral Anticoagulants (DOACs) in HIT

The American Society of Hematology (ASH) guidelines provide only conditional support for DOACs in HIT:

• DOACs (including apixaban) are suggested as an option only after initial treatment with a parenteral non-heparin anticoagulant 1
• Most clinical experience with DOACs in HIT is with rivaroxaban, not apixaban 1
• Limited evidence exists for apixaban in HIT with only case reports and small case series 3, 4, 5

Evidence Limitations for Apixaban in HIT

• Only 12 patients with HIT treated with apixaban were reported in a 2015 literature review 4
• Most patients received argatroban before transitioning to a DOAC 4
• While case reports show promising results, the evidence is insufficient to recommend apixaban as first-line therapy 3, 5

Recommended Treatment Algorithm for HIT

1. Confirm diagnosis:

   • Clinical assessment using 4Ts score
   • Laboratory confirmation with immunoassay for anti-PF4/heparin antibodies
   • Consider functional assay if immunoassay is positive 2

2. Initial treatment:

   • Start parenteral non-heparin anticoagulant (argatroban, bivalirudin, or danaparoid) 1, 2
   • Do not wait for laboratory confirmation before initiating treatment 2

3. Transition to oral anticoagulation:

   • Wait until platelet count recovers to >150 × 10^9/L 2
   • Options include:
     • Vitamin K antagonists (start at low dose, maximum 5 mg warfarin) 2
     • DOACs (rivaroxaban has the most evidence) 1

4. Duration of therapy:

   • For HIT with thrombosis: 3 months of anticoagulation 1
   • For isolated HIT: 4 weeks of anticoagulation 1

Important Considerations

• Avoid platelet transfusions unless life-threatening bleeding is present 2
• Document HIT diagnosis in medical records and provide patient with medical alert card 2
• Delay elective procedures until HIT antibodies are negative (typically >3 months) 2
• Monitor for thrombosis, as HIT is highly prothrombotic with up to 50% of untreated patients developing thrombosis 2

Conclusion

While apixaban may eventually prove to be an effective option for HIT based on limited case reports, current guidelines from the American Society of Hematology and American College of Chest Physicians recommend starting with a parenteral non-heparin anticoagulant (argatroban, bivalirudin, or danaparoid) as first-line therapy, with possible transition to a DOAC (preferably rivaroxaban based on available evidence) after platelet count recovery.