Heparin

Question 1

Therapeutic Classification

Answer 1

Anticoagulant

Question 2

Pharmacologic Classification

Answer 2

Indirect thrombin inhibitor

Question 3

Indications

Answer 3

DVT, pulmonary embolism, *unstable angina, evolving MI, and prevention of thrombosis in high-risk patients.

• Heparin and LMWH are preferred anticoagulants during pregnancy (don’t cross placenta)
• Also used to maintain patency of peripheral catheters and arterial lines.

Question 4

Contraindications

Answer 4

Active internal bleeding, serious bleeding pathologies, severe HTN, recent trauma, intracranial hemorrhage, bacterial endocarditis, sulfite sensitivity, severe thrombocytopenia.

• Some heparin products may contain sulfites and should not be administered to patients with sulfite sensitivity.
• IM injections should be avoided b/c they may cause serious bruising, bleeding, or hematomas.
• Caution must be used when administering heparin to patients with serious renal or hepatic impairment because the drug may rise to toxic levels.

Question 5

Mechanism of Action

Answer 5

Heparin activates the enzyme antithrombin III, which in turn inhibits thrombin. To a lesser extent, and by a separate mechanism, heparin also inactivates Factor Xa. High doses interfere with platelet aggregation.

Question 6

pregnancy category?

Answer 6

Pregnancy Category C - Cannot be given orally, does not cross placenta or into breast milk. Drug should be used with caution during the peripartum period due to risk of maternal hemorrhage.

Question 7

Adverse Effects

Answer 7

• Abnormal bleeding is common, occurring in about 10% → most serious adverse effect. May be major or minor, and may involve any system in the body. Dose dependant. If aPTT becomes excessively prolonged or bleeding is observed, discontinuation of the drug will result in loss of anticoagulant activity within hours.
• Mild allergic symptoms (fevers, chills, urticaria)
• Osteoporosis
• Skin lesions (esp. at site of parenteral injections)
• Epidural hematomas may occur when heparin or LMWHs are used in patients receiving spinal anesthesia or lumbar puncture (may result in permanent paralysis) frequent monitoring for neurologic impairment is essential.
• HIT occurs in up to 30%, symptoms range from mild to severe. Causes an increase in adverse thrombotic events. Markedly increases platelet aggregation and the patient may experience serious, or life-threatening thrombosis. May not become evident until several weeks after the drug is discontinued.

Question 8

Drug interaction with oral anticoagulants?

Answer 8

Increased effect.

Question 9

Drug interaction with drugs that inhibit platelet aggregation? (e.g. aspirin, indomethacin, ibuprofen)

Answer 9

Bleeding

Question 10

Drug interactions with nicotine, digoxin, tetracyclines, antihistimes?

Answer 10

Inhibit anticoagulation.

Question 11

Interactions with ginger, garlic, green tea, feverfew, or gingko?

Answer 11

Increased risk of bleeding.

Question 12

Nursing Considerations

Answer 12

• Complete health hx
• Baseline blood tests
• Monitor aPTT
• Collect blood for testing 30 min. prior to dose
• Monitor for signs of bleeding
• Apply firm pressure x 10 min. for needle sticks
• Reduce risk of trauma
• Keep heparin antidote (protamine sulfate) readily available

Question 13

Patient & Family Education

Answer 13

• Avoid activities that may result in injury
• Immediately report bleeding problems
• Menstruation may be increased
• Avoid smoking and alcohol
• Do not take other drugs or supplements
• Learn subQ injection techniques
• Inform dentist prior to procedure