Heparin

Question 1

Treatment dose of heparin

• Continue IV Infusion
• Weight based:

Answer 1

Continuous IV infusion:
- 5000-10,000 units bolus => then 1000U/hr. Titrate base on APTT

Weight based:

• LD: 80 units/kg
• MD: 18 units/kg/hr

Check aPTT Q6H or QID

Question 2

Prophylaxis dose of heparin

Answer 2

5000 - 10000 units SC Q8-12H

• Does not change PTT => no monitor
• SQ in lower abdomen, inner thigh, upper arm (rotate sites)

Question 3

Indication of heparin

Answer 3

• Thrombosis

- Embolism treatment/prophylaxis

Question 4

MOA

Answer 4

• Interferes with intrinsic pathway
• Act indirectly via a plasma cofactor anti-thrombin II => inhibit thrombin IIa and FXa.
• Neutralize activated clotting factors: 2, 9, 10, 11, 13.

Question 5

Route heparin is given

Answer 5

• IV (treatment)
• SC (prophylaxis)
• NEVER IM

Question 6

Dosage Form

Answer 6

• 1000, 2500, 5000, 7500, 10000, 20000 units/mL

Question 7

Monitoring parameter of Heparin

Answer 7

APTT: 1.5-2.5 x normal = 45-70s

• Check prior, 6H after initiation and 6H after any dose change
• After 2 consecutive w/in level => Q24H

CBC: Hgb, Hct, Platelet
- Monitor bleeding & HIT

Question 8

Renal dosing adjustment

Answer 8

NO

Question 9

ADEs

Answer 9

• Hypersensitivity
• Hemorrhage: avoid all ASA products
• Thrombocytopenia (HIT): monitor platelet
• HyperK (suppression of aldosterone)
• Osteoporosis (if use chronically)

Question 10

DDIs

Answer 10

Increase risk of bleeding

• Anti-platelet
• Thrombolytics
• Warfarin
• Cefoperazone
• Cefotetan
• Herbs: ginger, garlic, horse chectnut, feverfew, Vit E
• Ginseng: decrease INR

Question 11

OSA

• IV
• SC

Answer 11

• IV: Works immediately => good for rapid anticoagulation desired
• SC: works in 20-30min

Question 12

CI

Answer 12

Pt w/ potential to bleed more easily:

• Consume large amt of EtOH
• Actively bleeding
• Thrombocytopenia
• Intracranial hemorrhage
• Severe Hypertension
• Ulcerative lesions of GI tract
• Hx of HIT

Question 13

What is HIT

Answer 13

• Heparin induce thrombocytopenia => platelet count drops may fall < 100,000/mm3
• Occurs 5-14 days after starting heparin. Can occur up to 3 weeks after heparin d/c

Question 14

Drugs use for prevention/treatment of thrombosis in HIT

Answer 14

Direct thrombin inhibitor: directly inhibit clotting FIIa (thrombin) both bound and circulating

• Agatroban IV: Novastan => Liver dose adj
• Lepirudin IV: Refludan => Renal dose adj
• Bivalirudin IV: Angiomax => for PCI
• Desirudin (SC): Iprivask
• Dabigatran (PO): Pradaxa