desirudin


desirudin

(des-i-rude-in) desirudin,

Iprivask

(trade name)

Classification

Therapeutic: anticoagulants
Pharmacologic: thrombin inhibitors
Pregnancy Category: C

Indications

Prevention of deep-vein thrombosis (DVT) after hip-replacement surgery.

Action

Selectively inhibits free and clot-bound thrombin. Inhibition of thrombin prevents activation of factors V, VIII, and XII; conversion of fibrinogen to fibrin; platelet adhesion and aggregation.

Therapeutic effects

Decreased incidence of DVT and subsequent pulmonary embolism after hip-replacement surgery.

Pharmacokinetics

Absorption: Completely absorbed following subcutaneous administration.Distribution: Binds specifically and directly to thrombin.Metabolism and Excretion: 40–50% excreted unchanged by kidneys; some metabolism in kidneys and pancreas.Half-life: 2 hr.

Time/action profile (effect on aPTT)

ROUTEONSETPEAKDURATION
Subcutrapid1–3 hr12 hr

Contraindications/Precautions

Contraindicated in: Hypersensitivity to natural or recombinant hirudins; Active bleeding; Coagulation disorders.Use Cautiously in: Renal impairment (dosage change recommended if CCr ≤60 mL/min); Geriatric patients (due to age-related renal impairment); Hepatic impairment; Pregnancy (use only if benefits to mother outweigh fetal risk); Lactation, children (safety not established).Exercise Extreme Caution in: Spinal/epidural anesthesia (increased risk of spinal/epidural hematomas and their sequelae, especially when used with NSAIDs, platelet inhibitors, or other anticoagulants).

Adverse Reactions/Side Effects

Gastrointestinal

  • nausea

Hematologic

  • bleeding (life-threatening)
  • anemia

Local

  • injection site reactions
  • wound secretion

Interactions

Drug-Drug interaction

Dextran 40, systemic corticosteroids, thrombolytics, and other anticoagulants ↑ risk of bleeding (discontinue if possible; if not, monitor laboratory and clinical status closely).Agents altering platelet function including salicylates, NSAIDs, clopidogrel, ticlopidine, dipyridamole, and glycoprotein IIb/IIIa antagonists also ↑ risk of bleeding.

Route/Dosage

Subcutaneous (Adults) 15 mg every 12 hr, start 5–15 min prior to surgery, but after regional block (if used), for up to 12 days.

Renal Impairment

Subcutaneous (Adults) CCr 31–60 mL/min—start with 5 mg every 12 hr; further doses determined by daily aPTT; CCr <31 mL/min—start with 1.7 mg every 12 hr; further doses determined by daily aPTT.

Availability

Lyophilized powder for injection (requires reconstitution with specific diluent): 15.75 mg/vial with 0.6 mL ampule of diluent (contains mannitol, delivers 15 mg dose)

Nursing implications

Nursing assessment

  • Assess for signs of bleeding (bleeding gums, nosebleed, unusual bruising; black, tarry stools; hematuria; fall in hematocrit or BP; guaiac-positive stools; bleeding from surgical site). Notify physician if these occur.
  • Assess patient for evidence of thrombosis. Symptoms depend on area of involvement. Notify physician immediately; may require urgent treatment.
  • Monitor patients with epidural catheters frequently for signs of neurological impairment (midline back pain, numbness or weakness in lower limbs, bowel and/or bladder dysfunction). Notify physician immediately if these occur.
  • Observe injection sites for hematomas, ecchymosis, or inflammation.
  • Lab Test Considerations: Monitor activated partial thromboplastin time (aPTT) daily in patients with increased risk of bleeding and/or renal impairment. Monitor serum creatinine daily in patients with renal impairment. Peak aPTT should not exceed two times control. Reduce dose or discontinue desirudin until aPTT is <2 times control; resume at a lower dose.
    • If a patient is switched from oral anticoagulants to desirudin or from desirudin to oral anticoagulants, measure anticoagulant activity closely.
    • Thrombin time is not suitable for monitoring desirudin.
    • Monitor CBC. If hematocrit ↓ unexpectedly, assess patient for potential bleeding sites.

Potential Nursing Diagnoses

Ineffective tissue perfusion (Indications)
Risk for injury (Adverse Reactions)

Implementation

  • Reconstitute each vial with 0.5 mL of diluent provided for a concentration of 15.75 mg of desirudin/0.5 mL. Shake vial gently until fully reconstituted to a clear colorless solution. Do not administer solutions that are discolored, cloudy, or contain a particulate matter. Reconstituted solution should be used immediately, but is stable for 24 hr at room temperature and protected from light. Discard unused solution.
  • Subcutaneous: Withdraw all reconstituted solution into syringe with a 26- or 27-gauge, 1/2-inch length needle. Inject entire contents subcutaneously which will deliver 15 mg. Patient should be sitting or lying down during administration. Rotate sites between left and right anterolateral and left and right posterolateral thigh or abdominal wall. Inject entire length of needle while pinching skin between thumb and forefinger; continue to pinch skin throughout injection. Do not rub injection site following injection to prevent bruising.
  • Syringe Incompatibility: Do not mix with other diluents or medications.

Patient/Family Teaching

  • Advise patient to report symptoms of unusual bleeding or bruising to health care professional immediately.
  • Instruct patient not to take aspirin, NSAIDs, or herbal products during therapy without consulting health care professional.

Evaluation/Desired Outcomes

  • Decreased incidence of DVT and subsequent pulmonary embolism after hip-replacement surgery.