NSAIDs Mechanism of Action of Salicylates

NSAIDs (Non-Steroidal Anti-Inflammatory Drugs) are a class of medications used primarily to

reduce inflammation, relieve pain, and lower fever. They are commonly classified into several

categories based on their chemical structure and mechanism of action:

1. Salicylates

Example: Aspirin (Acetylsalicylic Acid)

2. Propionic Acid Derivatives

Examples: ibuprofen, Naproxen

3. Acetic Acid Derivatives

Examples: Diclofenac, Indomethacin

4. Oxicam Derivatives

Examples: Piroxicam, Meloxicam

5. Selective COX-2 Inhibitors

Examples: Celecoxib, Etoricoxib

Mechanism of Action of Salicylates (e.g., Aspirin)

Salicylates, such as aspirin, exert their effects primarily through the following mechanisms:

1. Inhibition of Cyclooxygenase (COX) Enzymes:

COX-1 and COX-2 Inhibition: Aspirin irreversibly inhibits both COX-1 and COX-2 enzymes.

COX-1 is involved in the production of prostaglandins that protect the gastric mucosa and

support platelet aggregation. COX-2 is involved in the production of prostaglandins that

mediate inflammation, pain, and fever.

Prostaglandin Synthesis Reduction: By inhibiting COX enzymes, aspirin reduces the synthesis of prostaglandins. This leads to decreased inflammation, pain, and fever.

2. Anti-Platelet Effect:

Irreversible Platelet Inhibition: Aspirin's inhibition of COX-1 in platelets leads to decreased

thromboxane A2 production, which is crucial for platelet aggregation. This effect is irreversible and lasts for the lifespan of the platelet (approximately 7-10 days).