Apixaban (eliquis)

# Apixaban (eliquis) ## Overview Apixaban is a direct, reversible inhibitor of free and clot-bound factor Xa. It inhibits platelet thrombus formation and prevents thrombin generation. It has a rapid onset and a half-life of approximately 12 hours. ## Primary Indications * Reduction of risk of stroke and systemic embolism in non-valvular atrial fibrillation (NVAF). * Treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE). * Reduction in the risk of recurrent DVT and PE following initial therapy. * Prophylaxis of DVT (which may lead to PE) in patients undergoing hip or knee replacement surgery. ## Adult Dosing * **NVAF:** 5 mg orally twice daily. * **DVT/PE Treatment:** 10 mg orally twice daily for 7 days, followed by 5 mg orally twice daily. * **DVT/PE Secondary Prevention:** 2.5 mg orally twice daily after at least 6 months of initial treatment. * **Post-op DVT Prophylaxis:** 2.5 mg orally twice daily; start 12–24 hours post-surgery. Hip replacement: duration 35 days. Knee replacement: duration 12 days. ## Pediatric Dosing Dosing is not FDA-approved for general pediatric use. Clinical trials (e.g., EINSTEIN-Jr) have investigated weight-based dosing for pediatric venous thromboembolism, but specific dosing protocols must be determined by a pediatric hematologist/pharmacist based on institutional guidelines or clinical trial data. ## Dose Adjustments * **NVAF Dose Reduction:** Reduce to 2.5 mg twice daily if the patient meets **at least two** of the following criteria: Age ≥80 years, Body weight ≤60 kg, or Serum creatinine ≥1.5 mg/dL. * **Renal Impairment:** No dose adjustment required for mild/moderate impairment. Use with caution in severe impairment (CrCl 15–29 mL/min); no formal recommendation for hemodialysis, though clinical use exists. * **Hepatic Impairment:** Avoid in severe hepatic impairment (Child-Pugh C). Use caution in moderate impairment (Child-Pugh B). ## Contraindications * Active pathological bleeding. * Severe hypersensitivity reactions (e.g., anaphylaxis). ## Adverse Effects * **Major:** Hemorrhage (GI, intracranial, ocular, epistaxis). * **Common:** Nausea, anemia, bruising, minor skin rashes. ## Key Drug Interactions * **Strong Dual Inhibitors/Inducers:** Apixaban is a substrate of CYP3A4 and P-glycoprotein (P-gp). * Avoid concurrent use with strong dual inhibitors (e.g., ketoconazole, itraconazole, ritonavir). * Avoid concurrent use with strong dual inducers (e.g., rifampin, carbamazepine, phenytoin, St. John's wort) as they significantly decrease apixaban exposure. ## Monitoring * **Baseline/Routine:** Baseline CBC, SCr, and LFTs. Monitor for signs of overt/occult bleeding. * **Renal/Hepatic:** Periodic assessment of renal function (CrCl) and hepatic function, especially if clinical status changes. * **Coagulation:** Routine monitoring of PT/INR or aPTT is **not** recommended; these tests do not accurately reflect the anticoagulant effect of apixaban. ## Clinical Pearls * **Missed Dose:** Take as soon as remembered on the same day; do not double the dose to make up for a missed one. * **Crushability:** Tablets can be crushed and suspended in 5% dextrose in water, apple juice, or water for patients with dysphagia (via NG or gastric tube). * **Surgery:** Discontinue at least 48 hours before elective surgery with moderate/high bleeding risk and at least 24 hours before low-risk surgery. * **Reversal:** Andexanet alfa is the specific reversal agent for life-threatening or uncontrolled bleeding, though availability may be limited. *** *Disclaimer: This information is for educational purposes only. Always verify current prescribing information, institutional protocols, and patient-specific factors via resources like Lexicomp, Micromedex, or the official FDA package insert before prescribing or administering medication.*