Anti-platelets - Clopidogrel

Question 1

What is clopidogrel used for?

Answer 1

**clopidogrel is usually prescribed with aspirin (but can be used alone)

1) Acute coronary syndrome
2) prevent occlusion of coronary artery stents
3) long term prevention of thrombotic arterial events in patients with cardiovascular , cerebrovascular and periphera artery disease.
4) reduce thrombus events in atrial fibrillation (when warfarin is not suited)

Question 2

How does clopidogrel work

Answer 2

clopidogrel prevents platelet aggregation and reduces risk of arterial occlusion by irreversibly binding to adenosine diphosphate (ADP) receptors on the surface of platelts.

(independant to COX pathway so works well with aspirin)

Question 3

What are the side effects of clopidogrel?

Answer 3

• bleeding
• GI upset (dyspepsia, abdo pain, diarrhoea)
• thrombocytopenia (rare)

Question 4

what are the contraindications of clopidogrel

Answer 4

• active bleeding
• stop 7 days before surgery
• used in caution with renal and hepatic impairment

Question 5

what are the drug interactions of clopidogrel?

Answer 5

• clopidogrel is activated by cytochrome P450 enzymes
  Clopidogrel’s efficacy will be reduced by P450 enzyme inhibitors e.g.
• Omeprazole
• ciprofloxacin
• erythromycin
• some antifungals
• some SSRIs

Question 6

What gastroprotection is used for patients taking clopidogrel?

Answer 6

• lansoprazole or pantoprazole.

***dont use omeprazole because it is a cytochome P450 inhibitor so clopidogrel wont be activated

Question 7

What is the prescription of clopidogrel for treatment of acute coronary syndrome?

Answer 7

loading dose 300 mg (once only)

then daily 75mg

Question 8

how long is clopidogrel prescribed for coronary stents?

Answer 8

12 months to reduce risk of stent thrombosis