What are the next steps in managing a patient with a confirmed Deep Vein Thrombosis (DVT) on Eliquis (apixaban), with mildly elevated platelet count (thrombocytosis) and slightly low hemoglobin (anemia)?

Management of DVT on Apixaban with Thrombocytosis and Mild Anemia

Continue apixaban at the current dose without modification, as the patient is one week into appropriate DVT treatment and the mildly elevated platelets with slightly low hemoglobin do not warrant anticoagulation changes at this stage. 1

Rationale for Continuing Current Anticoagulation

Apixaban Dosing Verification

• The standard FDA-approved dosing for DVT treatment is 10 mg orally twice daily for the first 7 days, then 5 mg twice daily thereafter 1
• Since the patient is one week post-diagnosis, verify they are now on the maintenance dose of 5 mg twice daily (if they correctly started at 10 mg twice daily) 1
• No dose adjustment is indicated based on mild laboratory abnormalities alone 1

Platelet Count Assessment

• Full therapeutic anticoagulation without modification is safe when platelet counts are ≥50 × 10⁹/L 2
• "Mildly elevated" platelets (thrombocytosis) do not contraindicate continued anticoagulation and may actually represent a reactive process to the acute thrombotic event 3
• Baseline laboratory monitoring per NCCN guidelines includes CBC, renal and hepatic function at initiation, then hemoglobin, hematocrit, and platelet count every 2-3 days for the first 14 days 3

Hemoglobin Monitoring

• Mild anemia requires investigation but does not automatically necessitate stopping anticoagulation unless there is active bleeding 1
• Apixaban increases bleeding risk, and concomitant anemia warrants closer surveillance for occult blood loss 1

Immediate Next Steps

Laboratory Monitoring

• Repeat CBC now to establish trend of both platelet count and hemoglobin 3
• Check comprehensive metabolic panel including renal function (creatinine clearance affects apixaban dosing considerations) 1
• Obtain PT/INR and aPTT as baseline values 3
• Repeat CBC in 3-5 days, then weekly through day 14 of treatment 3

Investigate Underlying Causes

• For thrombocytosis: Consider reactive causes (acute thrombosis itself, inflammation, infection, iron deficiency, malignancy) versus primary myeloproliferative disorder 3
• For anemia: Assess for occult bleeding (stool guaiac, review for hematuria, menstrual history if applicable), hemolysis labs, iron studies, and nutritional deficiencies 1
• If malignancy is suspected or confirmed, this significantly impacts long-term anticoagulation strategy 3

Bleeding Risk Assessment

• Examine patient for signs of bleeding: petechiae, ecchymoses, hematuria, melena, hematemesis, or other blood loss 1
• Review medication list for drugs that increase bleeding risk (aspirin, NSAIDs, other antiplatelet agents, SSRIs/SNRIs) 1
• Counsel patient on warning signs of bleeding and when to seek emergency care 1

Critical Decision Points

When to Consider Changing Anticoagulation

• If platelets drop below 50 × 10⁹/L: Consider dose reduction or switching to LMWH at modified doses 2
• If platelets drop below 25 × 10⁹/L: Withhold anticoagulation unless dealing with high-risk proximal DVT where platelet transfusion support may be considered 2
• If hemoglobin continues to decline: Investigate aggressively for bleeding source; consider holding anticoagulation if active bleeding identified 1

Heparin-Induced Thrombocytopenia (HIT) Consideration

• This is unlikely given the patient is on apixaban (not heparin) and has elevated (not decreased) platelets 3
• HIT typically presents with thrombocytopenia (platelet drop >50% from baseline) 5-10 days after heparin exposure 3
• If the patient received heparin or LMWH initially before apixaban, and platelets were previously normal but are now rising after stopping heparin, this represents recovery, not HIT 3

Cancer Screening

• The combination of unprovoked DVT with thrombocytosis and anemia should prompt age-appropriate cancer screening 3
• If cancer is diagnosed, LMWH (particularly dalteparin) is preferred over DOACs for the first 6 months in patients with active malignancy 3

Duration of Anticoagulation Planning

Standard DVT Treatment

• Continue apixaban 5 mg twice daily for minimum 3 months for provoked DVT 1
• For unprovoked DVT, consider extended therapy beyond 3-6 months 1
• After at least 6 months of treatment, may transition to reduced-intensity dosing (2.5 mg twice daily) for extended secondary prevention 1

Follow-up Schedule

• Recheck labs in 3-5 days to assess trends 3
• Clinical reassessment at 2 weeks, 1 month, and 3 months 3
• Repeat imaging is not routinely indicated unless symptoms worsen 3

Common Pitfalls to Avoid

• Do not stop apixaban abruptly without alternative anticoagulation, as this increases thrombotic risk 1
• Do not assume thrombocytosis is benign without investigating underlying causes, particularly malignancy 3
• Do not ignore declining hemoglobin even if mild; serial monitoring is essential to detect occult bleeding early 1
• Do not transfuse platelets unless there is active life-threatening bleeding, as this is not indicated for thrombocytosis 3
• Do not switch to warfarin alone if HIT were suspected, as warfarin can worsen thrombosis in acute HIT 3