Pharmacology Third Year

1. CLASSIFICATION
1. NON SELECTIVE COX INHIBITORS:
a. Salycilates: Aspirin
b. Ibuprofen
c. Indomethacin
d. Diclofenac
f. Piroxicam
g. Mefenamic acid
2. SELECTIVE COX-2 INHIBITORS:
Celecoxib, Meloxicam
2. ANALGESIC, ANTIPYRETIC WITH POOR ANTI-
INFLAMMATORY ACTION: Paracetamol
Non-Steroidal Anti-inflammatory Drugs
(NSAIDs)

2. NSAIDs
• Mechanism of Action
• Inhibits cyclo-oxygenase enzyme = ↓↓ Prostaglandin synthesis
COX-I Most cells in the body
COX-II Inflammatory and immune cells
COX-III Hypothalamic temperature control center
NSAIDs that act on COX-I, COX-II & COX-III, more side
effects
Selective COX-II NSAIDs, less side effects

3. NSAIDs
Common Pharmacological Effects
• Analgesic (CNS and peripheral effect)
• Antipyretic (CNS effect)
• Anti-inflammatory (except Paracetamol)
• Antiplatelet effect:
– prevents platelet aggregation. ( Aspirin low dose)
Common Adverse Effects
• Gastritis and peptic ulceration with bleeding (inhibition of PG
+ other effects)
• Platelet Dysfunction
• Acute Renal Failure in susceptible persons
• Sodium+ water retention and edema
• Analgesic nephropathy

4. NSAIDs
ASPIRIN: Actions & Uses
Antiplatelet:
Prophylaxis of angina & myocardial infarction (MI)
Analgesic : Mild to moderate pain
Acute dental pain as in pulpitis, dentoalveolar abscess or post
dental surgical procedures.
Headache, musculoskeletal pain & arthritic pains
Anti-inflammatory: Rheumatic fever, rheumatoid arthritis,
Antipyretic : Fever

5. NSAIDs
Adv effects of Aspirin
Gastritis, Peptic ulcer & GI bleeding.
Reyes’ syndrome in children with viral fever
Salicylism:
 doses => Tinnitus, vertigo, vomiting &hearing
Contraindications:
• Bleeding disorders (Hemophilia),
• Peptic ulcer,
• Children with Viral fever,
• Hypersensitivity/bronchial asthma,

6. NSAIDs
INDOMETHACIN – Potent NSAID.
Non selective COX-inhibitor,
Inhibition of Phospholipase A & C,
↓ PMN migration.
Uses;
Acute gouty arthritis, ankylosing spondylitis, osteoarthritis,
Medical closure of Patent Ductus Arteriosus
Uterine relaxant ( tocolytic agent ).

7. NSAIDs
PARACETAMOL
• Antipyretic, Analgesic & Weak Anti-inflammatory
Uses: Fever, Headache, myalgias, etc.
Safe in patients with peptic ulcer, hemophilia, children with
viral fever, bronchial asthma
Adv effects:
Least GI and platelet effects
•  dosage = Hepatic damage due to accumulation of a toxic
metabolite, N-acetyl-benzoquinone
Antidotes: Acetylcysteine & Methionine

8. NSAIDs
SelectiveCOX-2 Inhibitors (COXIBs)
• Meloxicam, Celecoxib
• More selective inhibition of Cyclooxygenase-II enzyme
• Long duration of action
– given once or twice daily -- better patient compliance
• Least GI effects
Adverse effects:
• Thrombosis (Risk of myocardial infarction & stroke )
• Nephrotoxicity