How should I start Eliquis (apixaban) for acute popliteal deep‑vein thrombosis in an 80‑year‑old patient weighing ≤60 kg with serum creatinine ≥1.5 mg/dL, including loading dose, maintenance dose, and contraindications?

Eliquis (Apixaban) Starter Pack Directions for Acute Popliteal DVT

For an 80-year-old patient weighing ≤60 kg with serum creatinine ≥1.5 mg/dL and acute popliteal DVT, start apixaban 10 mg orally twice daily for 7 days, then reduce to 5 mg twice daily for at least 6 months. 1

Loading Dose Regimen

• Initial 7 days: Apixaban 10 mg orally twice daily 2, 3, 1
• After day 7: Apixaban 5 mg orally twice daily for completion of treatment (minimum 6 months) 2, 3, 1
• The first dose should be taken as soon as the diagnosis is confirmed; no parenteral anticoagulation bridge is required before starting apixaban 2

Critical Dosing Considerations for This Patient

Important: Despite this patient meeting criteria for dose reduction in atrial fibrillation (age ≥80 years, weight ≤60 kg, creatinine ≥1.5 mg/dL), the standard full-dose regimen (10 mg twice daily × 7 days, then 5 mg twice daily) is used for acute VTE treatment. 1 The 2.5 mg twice daily dose is only for atrial fibrillation patients with ≥2 of these characteristics, not for VTE treatment. 1

Renal Function Assessment

• Calculate creatinine clearance using Cockcroft-Gault equation to determine if apixaban is appropriate 2, 1
• Absolute contraindication: CrCl <15 mL/min—apixaban must be avoided 2, 3, 1
• Use with caution: CrCl 15-29 mL/min—limited data exist, but apixaban may be used if benefits outweigh risks 1
• Approximately 27% of apixaban clearance occurs via renal excretion, with half-life potentially extending to 17 hours in elderly patients with renal impairment 4, 5

Contraindications and Precautions

Absolute Contraindications

• Active pathological bleeding 1
• Severe hepatic impairment (transaminases >2× upper limit of normal or total bilirubin >1.5× upper limit of normal) 2, 3, 1
• CrCl <15 mL/min 2, 3, 1

Relative Contraindications Requiring Careful Assessment

• Recent surgery or invasive procedure with high bleeding risk (wait 24-72 hours for adequate hemostasis before starting) 6, 1
• Active gastric or gastroesophageal lesions (LMWH preferred in this setting due to higher GI bleeding risk with DOACs) 2
• Concurrent use of dual antiplatelet therapy or other anticoagulants 1
• History of intracranial hemorrhage or bleeding diathesis 1

Baseline Laboratory Testing

Before initiating apixaban, obtain: 2

• Complete blood count with platelet count 2
• Comprehensive metabolic panel including creatinine (to calculate CrCl) 2
• Hepatic function panel (AST, ALT, total bilirubin) 2
• PT/INR and aPTT (for baseline documentation only—not for monitoring) 2, 3

Note: Unlike warfarin, apixaban does not require INR monitoring during treatment, as it has fixed dosing and predictable pharmacokinetics. 3, 1

Monitoring During Treatment

Laboratory Monitoring

• Hemoglobin/hematocrit every 2-3 days for first 14 days if inpatient, then every 2 weeks or as clinically indicated 2
• Reassess renal function periodically, especially in elderly patients, as surgical procedures or acute illness may affect kidney function and apixaban clearance 6
• Do not monitor: INR (clinically irrelevant for apixaban), anti-factor Xa levels (not recommended for routine monitoring), or D-dimer (not indicated once treatment initiated) 3, 4

Clinical Monitoring

• Assess for signs of bleeding (bruising, hematuria, melena, hemoptysis, neurological changes) 2, 1
• Evaluate for recurrent VTE symptoms (new leg swelling, chest pain, dyspnea) 3, 4
• Monitor for signs of compartment syndrome if hematoma develops, even in painless presentations 4

Missed Dose Instructions

• If a dose is missed, take it as soon as remembered on the same day 1
• Resume twice-daily dosing at the regular schedule 1
• Never double the dose to make up for a missed dose 1

Evidence Supporting This Regimen

The AMPLIFY trial demonstrated that this apixaban dosing regimen was noninferior to enoxaparin/warfarin for preventing recurrent VTE (2.3% vs 2.7%; relative risk 0.84,95% CI 0.60-1.18), with significantly lower major bleeding rates (0.6% vs 1.8%; relative risk 0.31,95% CI 0.17-0.55; P<0.001). 2, 3, 7

Common Pitfalls to Avoid

• Do not use the 2.5 mg twice daily dose for initial VTE treatment, even in elderly patients with low body weight and elevated creatinine—this dose is only for atrial fibrillation or extended VTE prophylaxis after completing 6 months of full-dose therapy 1
• Do not bridge with parenteral anticoagulation before starting apixaban for acute VTE—apixaban is initiated directly without heparin overlap, unlike warfarin or edoxaban 2
• Do not perform neuraxial procedures (spinal/epidural anesthesia) while on therapeutic apixaban due to risk of spinal hematoma and permanent paralysis 1
• Do not restart apixaban immediately after high-risk bleeding or surgery—wait until adequate hemostasis is established (typically 24-72 hours) 6, 1