Argatroban

INTRODUCTION

Indications

Prophylaxis or treatment of thrombosis in patients with heparin-induced thrombocytopenia. As an anticoagulant in patients with or at risk for heparin-induced thrombocytopenia who are undergoing percutaneous coronary intervention (PCI).

Action

Inhibits thrombin by binding to its receptor sites. Inhibition of thrombin prevents activation of factors V, VIII, and XII; the conversion of fibrinogen to fibrin; platelet adhesion and aggregation. Therapeutic Effects: Decreased thrombus formation and extension with decreased sequelae of thrombosis (emboli, postphlebitic syndromes).

Adverse Reactions/Side Effects

CV: hypotension. GI: diarrhea, nausea, vomiting. Hemat: BLEEDING. Misc: ALLERGIC REACTIONS, INCLUDING ANAPHYLAXIS, fever.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Assess for signs of bleeding and hemorrhage (bleeding gums; nosebleed; unusual bruising; black, tarry stools; hematuria; fall in hematocrit or blood pressure). Notify physician or nursing staff immediately if this drug causes excessive anticoagulation.

• Monitor signs of allergic reactions and anaphylaxis, including pulmonary symptoms (tightness in the throat and chest, wheezing, cough, dyspnea) or skin reactions (rash, pruritus, urticaria). Notify physician or nursing staff immediately if these reactions occur.

• Assess blood pressure periodically and compare to normal values (See Appendix F). Report low blood pressure (hypotension), especially if patient experiences dizziness, fatigue, or other symptoms.

Interventions

• Use caution with any physical interventions that could increase bleeding, including wound débridement, chest percussion, joint mobilization, and application of local heat.

Patient/Client-Related Instruction

• Instruct patient to immediately report signs of GI bleeding, including abdominal pain, vomiting blood, blood in stools, or black, tarry stools.

• Instruct patient to report other bothersome side effects such as severe or prolonged fever or GI problems (nausea, vomiting, diarrhea).

Pharmacokinetics

Absorption: IV administration results in complete bioavailability.

Distribution: Unknown.

Metabolism and Excretion: Mostly metabolized by the liver; excreted primarily in feces via biliary excretion. 16% excreted unchanged in urine, 14% excreted unchanged in feces.

Half-life: 39–51 min (increased in hepatic impairment).

Contraindications/Precautions

Contraindicated in: Major bleeding; Hypersensitivity; Lactation.

Use Cautiously in: Hepatic impairment (↓ initial infusion rate recommended); OB: Use only if clearly needed; Pedi: Safety not established in children <18 yr.

Interactions

Drug-Drug: Risk of bleeding may be ↑ by concurrent use of antiplatelet agents, thrombolytic agents, or other anticoagulants.

Drug-Natural: ↑ bleeding risk with anise, arnica, chamomile, clove, ...