PARENTERAL ANTICOAGULANTS

Question 1

Which heparin is referred to as the
“standard heparin”?

Answer 1

Heparin (unfractioned)

Question 2

Which has a longer duration of action? LW
Heparin or Heparin (unfractioned)?

Answer 2

LMWH
H(UF) = shorter

Question 3

Why are LW Heparin generally more preferred?

Answer 3

• Lower risk of heparin-induced thrombocytopenia
• Standard prophylactic regimen does not require anticoagulant monitoring
• Once-daily subcutaneous administration is possible for some indications

Question 4

When is Heparin
(unfractionated) more preferred over LW Heparin?

Answer 4

• high risk of bleeding because its effect can be terminated rapidly by stopping the infusion

Question 5

Which type of heparin is more preferred in the prevention and treatment of DVT?

Answer 5

LMWH

Question 6

Examples of Low-molecular weight heparins

Answer 6

• Dalteparin Sodium (Fragmin)
• Enoxaparin Sodium
  (Clexane)
• Tinzaparin Sodium (Innohep)

Question 7

CI

Answer 7

• Haemorrhage
• Thrombocytopenia (including history of heparin induced thrombocytopenia)
• Severe hypertension
• Peptic ulcer

Question 8

SE

Answer 8

1. Haemorrhage
2. Heparin-induced thrombocytopenia
3. Hyperkalemia (Rare, unless at high risk)
4. Osteoporosis (Rare)

Question 9

Haemorrhage

Answer 9

• Withdraw
• However, if rapid withdrawal is needed, Protamine Sulfate is a specific antidote
• Although Protamine Sulfate only has partial reverse effects on LW Heparin

Question 10

Heparin-induced
thrombocytopenia

Answer 10

Signs include:
- 30% reduction in platelet count
- Thrombosis
- Or Skin allergy
- If suspected/confirmed,

STOP treatment
- Give an alternative
anticoagulant e.g. Danaparoid
- Ensure platelet counts return to normal in those who require warfarin

Question 11

Monitoring

Answer 11

1. Heparin-induced thrombocytopenia
   - Monitor platelets before treatment
   - Regular monitoring platelets needed if duration is longer than 4 days
2. Hyperkalaemia
   - Plasma-potassium concentration should be measured in patients

Question 12

Interactions

Answer 12

• Drugs with anticoagulant effects e.g. Warfarin, DOACS etc
• Drugs that increase serum potassium (e.g. ACE inhibitor, spironolactone)

Question 13

Pregnancy

Answer 13

• Yes
• They can be used for managing VTE
• because they do NOT cross the placenta
• LW Heparins are preferred over Heparin because they have a lower risk of
  osteoporosis and of heparin-induced thrombocytopenia

Question 14

What type of heparin is more preferred in renal impairment?

Answer 14

• heparin (unfractionated) is more preferable in renal impairment than LW Heparins

Question 15

Heparinoids

Answer 15

• Danaparoid Sodium
• Used in Prophylaxis of DVT
• Used in patients who develop heparin-induced thrombocytopenia

Question 16

Hirudins

Answer 16

• Bivalirudin
• Used in unstable angina, NSTEMI & STEMI

Question 17

What are Heparin flushes used for and what is as effective as it?

Answer 17

• Maintaining patency of venous and arterial catheters
• Their use should be kept to a minimum
• NaCl 0.9% is as effective

Question 18

What is Fondaparinux sodium?

Answer 18

• A synthetic pentasaccharide that inhibits activated factor X
• Has a role in VTE and unstable angina, NSTEMI