Eliquis | Pharmacology Mentor

Generic Name

Eliquis

Brand Names

** Eliquis

Mechanism

Selective, reversible inhibition of the active site of *cofactor‑dependent* Factor Xa.
Blocks conversion of prothrombin to thrombin, thereby reducing fibrin clot formation.
Does not inhibit Factor IIa (thrombin) or other coagulation pathways, resulting in a predictable anticoagulant effect with minimal need for laboratory monitoring.

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Pharmacokinetics

Parameter	Value	Notes
Absorption	~50–60 % oral bioavailability; peak plasma level in 3–4 h	Food → ~1‑2 h delay, but no dose adjustment required
Distribution	Vd ~21 L; ~90 % serum protein binding	Highly lipophilic; crosses placenta and breast milk
Metabolism	CYP3A4/5, CYP2C8, CYP2C9, CYP2J2; minor role of P‑glycoprotein	Two‑step oxidative metabolism to inactive metabolites
Elimination	50–70 % renal (glomerular filtration + active tubular secretion) 30–40 % via feces	Half‑life 8–12 h; steady state in 5–7 days
Special populations	Dose adjustments recommended in severe CKD (CrCl < 15 mL/min) and with potent CYP3A4/P‑gp inhibitors

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Indications

Venous thromboembolism (VTE) prevention post‑orthopedic surgery (total hip or knee replacement).
Treatment and secondary prevention of VTE (deep‑vein thrombosis or pulmonary embolism).
Atrial fibrillation (AF) with risk of stroke (CHA₂DS₂‑VASc ≥ 2 in men, ≥3 in women).
Secondary stroke prevention in patients with non‑valvular AF.

*Preferred over warfarin* in most non-valvular AF patients due to fewer drug‑drug interactions and no need for INR monitoring.

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Contraindications

Contraindicated in:
Severe renal impairment (CrCl < 15 mL/min) or end‑stage kidney disease on dialysis.
Active major bleeding.
Recent major surgery or trauma with high bleeding risk.
Known hypersensitivity to apixaban or any excipients.

Warnings:
• *Bleeding:* Major bleeding and intracranial hemorrhage risk—monitor with clinical signs, especially in elderly or patients on concomitant antiplatelet agents.
• *Drug interactions:* Strong CYP3A4 and P‑gp inhibitors/inducers can ↑/↓ plasma levels.
• *Reversal:* Andexanet alfa (FDA‑approved) is the specific antidote for life‑threatening bleeding; activated charcoal if ingestion within 2 h.

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Dosing

Condition	Standard Dose	Frequency	Notes
VTE Treatment	10 mg BID first 7 days, then 5 mg BID	Twice daily	Reduce dosing after 7 days unless patient has renal dysfunction
AF Stroke Prevention	5 mg BID	Twice daily	Same 5 mg BID for all adults; adjust only in CKD CrCl 15–29 mL/min: 2.5 mg BID
VTE Prevention (post‑hip/knee)	2.5 mg BID	Twice daily	30 days after discharge or 35 days after surgery

• Take with food to improve absorption.
• Avoid crushed or chewed tablets; swallow whole.
• For patients starting or stopping concomitant CYP3A4/P‑gp modulators, consider a 2–5 day overlap period.

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Adverse Effects

Common (≥5 %):
Bleeding (gastrointestinal, genitourinary).
Thrombocytopenia (rare).
Serious (≤2 %):
Intracranial hemorrhage.
Anaphylaxis (very rare).
Severe bleeding requiring transfusion or invasive procedures.

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Monitoring

Routine monitoring: Not required; no INR or aPTT needed.
Special labs:
Renal function (CrCl) at baseline, every 3 months, or sooner if renal disease suspected.
Liver function if hepatic dysfunction is present.
Clinical: Watch for signs of bleeding (bruising, hematuria, melena).
Drug interactions: Review P‑gp and CYP3A4 inhibitors/inducers.

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Clinical Pearls

No lab monitoring: The main advantage of Eliquis—no INR or aPTT needed. Only check renal function, especially in the elderly or CKD.
Drug‑interaction vigilance: Combine cautiously with strong CYP3A4 or P‑gp inhibitors (e.g., ketoconazole, diltiazem) that could double anti‑coagulation risk.
Reversal strategy: Andexanet alfa is the only specific antidote; ensure availability in high‑bleeding risk settings.
Dose adjustment nuance: Even in CrCl 30–39 mL/min, use the standard dose; only CrCl  Keywords: Eliquis, apixaban, factor Xa inhibitor, DOAC, anticoagulant therapy, atrial fibrillation, VTE prevention, renal dosing, drug interactions, bleeding risk, andexanet alfa.