NSAIDs

Question 1

What are the indications of Aspirin?

Answer 1

1) Treatment of Acute Coronary Syndrome & Acute ischemia stroke

2) Prevention of Atherothrombotic events in people with IHD, Cerebrovascular disease & peripheral vascular disease

3) Pain & fever reducer at higher doses even though other NSAIDs are preferred.

Question 2

What is the MOA of Aspirin?

Answer 2

irreversibly inhibits cyclooxygenase1&2 (COX1 & COX2) enzymes, stopping prostoglandin formation, thereby preventing platelet aggregation. This anti platelet effect last for the entire platelet’s lifetime (7-10 days) and they have no nuclei to allow synthesis of new COX enzymes.

Question 3

What are the side effects of Aspirin?

Answer 3

GI upset

GI ulceration

Bleeding

Hypersensitivity rxns like Bronchospasm

Tinnitus at higher doses

symptoms of aspirin overdose: Tinnitus, Confusion, Convulsion, hyperventilation, metabolic acidosis, respiratory arrest, cardiovacular collapse.

Question 4

What are the contraindications of Aspirin?

Answer 4

Active bleeding

Children under 16 due to risk of reye’s syndrome

3rd trimester pregnancy due to premature closure of ductus arteriosus

Peptic ulcer (consider adding PPIs - Gastric protection)

Caution in Gout (as it may trigger an attack)

Question 5

What are some important drug interactions with Aspirin?

Answer 5

reacts synergistically with other antiplatelets & anticoagulants, so it might increase your risk of bleeding

Question 6

How do you prescribe Aspirin?

Answer 6

ACS:
Loading dose = 300mg
Maintenance = 75mg

Acute ischemic stroke:
Loading dose = 300mg OD x 14/7
Maintainace dose = 75 mg OD (in combination with dipyridamole)

Prevention of Atherothrombotic events:
Maintenance dose = 75mg OD

Pain & Fever:
900mg q6hrs (max 4g OD)