abciximab

Brand: ReoPro

⚠ BBW ISMP High Alert Prototype Drug
Drug Class: glycoprotein IIb/IIIa inhibitor
Drug Family: antiplatelet
Subclass: chimeric monoclonal antibody fragment (Fab)
Organ Systems: cardiovascularhematology-oncology

Mechanism of Action

Chimeric human-murine Fab fragment that binds to glycoprotein IIb/IIIa receptors on platelets with high affinity, preventing fibrinogen and von Willebrand factor binding, thereby blocking the final common pathway of platelet aggregation regardless of the triggering stimulus.

glycoprotein IIb/IIIa receptor (integrin alphaIIb-beta3)

Indications

  • adjunct to PCI in high-risk coronary interventions
  • unstable angina not responding to conventional therapy when PCI planned within 24 hours

Contraindications

  • active internal bleeding
  • recent (within 6 weeks) significant GI or genitourinary bleeding
  • recent stroke (within 2 years)
  • major surgery within 6 weeks
  • history of vasculitis
  • thrombocytopenia <100,000 cells/mcL
  • severe uncontrolled hypertension
  • oral anticoagulants within 7 days unless PT <1.2x control

Adverse Effects

Common

  • bleeding (access site, GI, genitourinary)
  • thrombocytopenia
  • hypotension
  • nausea

Serious

  • major hemorrhage
  • severe acute thrombocytopenia
  • intracranial hemorrhage
  • HACA formation (human anti-chimeric antibodies)

Pharmacokinetics (ADME)

Absorption IV administration only
Distribution rapidly binds to GP IIb/IIIa receptors; free plasma levels low
Metabolism proteolytic degradation; not CYP-dependent
Excretion clearance via receptor-mediated endocytosis and reticuloendothelial system
Half-life initial ~10 minutes (plasma); platelet-bound half-life 12-24 hours (platelet-bound drug persists)
Onset immediate (within minutes of bolus)
Peak end of bolus
Duration platelet function recovery 24-48 hours after discontinuation
Protein Binding N/A (receptor-bound)
Vd rapidly distributes to platelet receptor pool

Drug Interactions

Drug / Agent Mechanism Severity
heparin (concurrent use) combined antiplatelet/anticoagulant effect substantially increases bleeding risk; heparin dose reduction required during PCI major
thrombolytics additive hemorrhagic risk; generally contraindicated in combination major
other GP IIb/IIIa inhibitors additive receptor blockade increases thrombocytopenia and bleeding risk major

Nursing Considerations

  1. Monitor platelet count 2-4 hours after bolus and again at 24 hours; abciximab causes acute profound thrombocytopenia in 1-2% of patients — if platelets fall below 100,000, notify physician and prepare for potential drug discontinuation.
  2. Minimize femoral access site trauma; apply direct pressure for 30 minutes after sheath removal; patient should remain supine with head elevated no more than 30 degrees for at least 6 hours post-PCI.
  3. Monitor all access sites, urine, stool, and nasogastric aspirate for blood; document IV line sites and avoid unnecessary arterial punctures during and for 12 hours post-infusion.
  4. Keep aPTT between 60-85 seconds during heparin co-administration; verify reduced heparin protocol per institutional PCI orders when abciximab is used concurrently.

Clinical Pearls

  • Abciximab's irreversible binding to GP IIb/IIIa means platelet function does not recover until enough new platelets are generated — approximately 24-48 hours; platelet transfusion can restore function in cases of life-threatening bleeding.
  • The chimeric structure of abciximab (part murine) can elicit human anti-chimeric antibodies (HACA), making re-administration potentially less effective and potentially more immunogenic than with the small-molecule GP IIb/IIIa inhibitors.

Safety Profile

Pregnancy use-with-caution
Lactation insufficient-data
Renal Adjustment Not required
Hepatic Adjustment Not required
TDM Not required