Description
Introduction to Anti-inflammatory Drugs
• Inflamation
Normal protective response to
tissue injury
caused by
• Physical Trauma
• Noxicious Chemicals
• Microbial Agents
✓ When Inflammation process is
subside
When Healing is Complete
• Classification of anti-inflammatory drugs
• 2. The mechanisms of NSAIDs
• Cyclooxygenases: COX 1, COX 2
• Peripheral mechanisms of pain
• Pharmacodynamic Effects of NSAIDs
• antipyretic : compared with chlorpromazine
• Analgesic : compared with Opioids
• Anti-inflammatory: compared with glucocorticoid
• NSAIDs and Platelets/Endothelial Cells
• Negative or adverse effects
Gastric irritant
Decreased renal perfusion
Bleeding
• 5. Drug interactions
• Salicylates – aspirin
• Aspirin
Dose-Dependent Effects:
Low: < 300mg
blocks platelet aggregation
Intermediate: 300-2400mg/day
antipyretic and analgesic effects
High: 2400-4000mg/day
anti-inflammatory effects
• Side effects of aspirin
• NSAIDs: Classification by half-life
• Acetaminophen
• COX-2 selective anti-
inflammatory drugs
• TNF- inhibitor
Etanercept
Infliximab
Adalimumab
They are recombinant proteins that can not orally taken;
The long-term safety is not determined.
- Subject:- pharmacology 3
- Course:- B.pharm (pharmacy),
- Semester:- 5th sem , sem :- 5
Introduction to Anti-inflammatory Drugs www.remixeducation.in 2012.10 Inflamation Normal protective response to tissue injury caused by • Physical Trauma • Noxicious Chemicals • Microbial Agents www.remixeducation.in Inflamation Body’s effort • To inactive or destroy invading organisms • To remove Irritants, and • Set the stage for tissue repair www.remixeducation.in When Inflammation process is subside When Healing is Complete www.remixeducation.in Peripheral mechanisms of pain www.remixeducation.in Classification of anti-inflammatory drugs (1) Non-Steroid Anti-Inflammatory Drugs (NSAIDs) (Antipyretic-Analgesic and Anti-inflammatory Drugs) eg. aspirin, Diclofenac, Flurbiprofen, ibuprofen, indomethacin, Ketoprofen, Meloxicam, Methyl salicylate, Naproxen, Piroxicam, (2) COX 2 inhibitor Celecoxib (3) Other Analgesics Acetaminophen (4) Drugs use For Arthritis Infliximab, Methotrexate, Rituximab, Chloriquine, Gold Salts, (5) Drugs for Gout www.remixeducation.in Allopurinol, Colchicine, Probenecid, 2. The mechanisms of NSAIDs www.remixeducation.in 2. The mechanisms of NSAIDs Cyclooxygenases: COX 1, COX 2 - PGs, mostly by COX-1, are constitutively expressed in almost all tissues; COX-2 appears to only be constitutively expressed in the brain, kidney, bones, reproductive organs, and some neoplasms - Under normal physiologic conditions, PGs play an essential homeostatic role in cytoprotection of gastric mucosa, hemostasis, renal physiology, gestation, and parturition - In platelets there is only COX-1exist (converts arachidonic acid to TxA2) - COX-1 predominant in gastric mucosa (source of cytoprotective PGs) - The production of PGs, (inducible COX-2 activity >> COX-1) at sites of inflammation propagate pain, fever www.remixeducation.in 2. The mechanisms of NSAIDs NSAID inhibition of PG production alleviates most of the pathologic effects associated with inflammation, but it also interferes with the physiologic role of these molecules Consequently, long-term therapy with nonspecific NSAIDs is frequently limited by their adverse effects, particularly those caused by erosion of gastric mucosal protection —— GI bleeding www.remixeducation.in 3. Pharmacodynamic Effects of NSAIDs Positive Analgesic (0.3-0.6 g/day) - refers to the relief of pain by a mechanism other than the reduction of inflammation (for example, headache); - produce a mild degree of analgesia which is much less than the analgesia produced by opioid analgesics such as morphine anti-inflammatory (3-5 g/day) - these drugs are used to treat inflammatory diseases and injuries, and with larger doses - rheumatoid disorders antipyretic (0.3-0.6 g/day) - reduce fever; lower elevated body temperature by their action on the hypothalamus; normal body temperature is not reduced antiplatelet (30-100 mg/day)- inhibit platelet aggregation, prolong bleeding time; have anticoagulant effects www.remixeducation.in 3. Pharmacodynamic Effects of NSAIDs antipyretic : compared with chlorpromazine NSAIDs Chlorpromazine Effects Inhibit PGs synthesis Inhibit thermotaxic center in and enhance hypothalamus. The body thermolysis temperature change according to the environment. Clinical usage Lower the abnormal artificial hibernation, high temperature to Hypothermic anesthesia, normal. Used for various fever. Side effects GI reactions,no addiction Extrapyramidal effects www.remixeducation.in 3. Pharmacodynamic Effects of NSAIDs Analgesic : compared with Opioids NSAIDs Opioids Effects Inhibit PGs and TxA2 Stimulate opioid receptors synthesis by inhibiting COX Clinical usage Headache, toothache, Various pain including neuralgia, arthronalgia,, severe pain courbature (Lambague) menalgia Side effects GI reactions,no addiction Addiction www.remixeducation.in 3. Pharmacodynamic Effects of NSAIDs Anti-inflammatory: compared with glucocorticoid NSAIDs Glucocorticoid Effects Inhibit PGs and TxA2 Various effects including synthesis by inhibition of PLA2 inhibiting COX Clinical usage Rheumatic, rheumatoid, Various inflammation trauma Side effects GI reactions Various side effects, such as metabolism disturbance, damage of defense etc. www.remixeducation.in 3. Pharmacodynamic Effects of NSAIDs www.remixeducation.in NSAIDs and Platelets/Endothelial Cells 4. Adverse Effects associated with NSAIDs Non-selective Negative or adverse effects Gastric irritant Decreased renal perfusion Bleeding www.remixeducation.in 5. Drug interactions www.remixeducation.in Salicylates - aspirin www.remixeducation.in Salicylism Aspirin Dose-Dependent Effects: Low: < 300mg blocks platelet aggregation Intermediate: 300-2400mg/day antipyretic and analgesic effects High: 2400-4000mg/day anti-inflammatory effects www.remixeducation.in Side effects of aspirin • Gastrointestinal symptoms • CNS toxicity • Allergic reaction (urticaria, angioneurotic edema, aspirin asthma, occasionally anaphylactic shock) • Salicylate reaction (CNS reaction) • Renal damage • Hematologic effects • Metabolic acidosis stimulates medullary respiratory center respiratory alkalosis www.remixeducation.in 4. Adverse Effects associated with NSAIDs • Salicylism dose > 5g/d: CNS symptoms, including mental confusion; hyperventilation. Rescure: i.v. NaHCO3 promote the excretion • Hepatic damage Overdose: hepatic damage Reye’s syndrome (kids) severe hepatic damage and encephalopathy www.remixeducation.in NSAIDs: Classification by half-life Plasma Elimination Half Lives Short Half Life (< 6 hours): more rapid effect and clearance • Aspirin (0.25-0.33 hrs), • Diclofenac (1.1 ± 0.2 hrs) • Ketoprofen (1.8 ± 0.4 hrs), • Ibuprofen (2.1 ± 0.3 hrs) • Indomethacin (4.6 ± 0.7 hrs) Long Half Life (> 10 hours): slower onset of effect and slower clearance • Naproxen (14 ± 2 hrs) • Sulindac (14 ± 8 hrs), • Piroxicam (57 ± 22 hrs) www.remixeducation.in Acetaminophen - analgesia - antipyretic - no significant anti-inflammatory effects - no gastric irritation - no platelet function interference - half life 2 –3 h - weak inhibitor of COX-1, -2; - not contraindicated for asthma - not associated with Reye’s Syndrome - The major concern regarding the use of acetaminophen is the potential for high doses to cause liver toxicity www.remixeducation.in Differences between NSAIDs and Acetaminophen www.remixeducation.in • indomethacin stronger efficacy, controlling special types of fever; severe adverse effects • Sulindac Its metabolite possess 500 fold PG inhibition than itself. Strong anti-inflammation and lower adverse effects than indomethacin. • Etodolac Used as a pain killer after operation Lower GI upset www.remixeducation.in • Tolmetin Moderate anti-inflammation and mild analgesic and antipyretic effect • ibuprofen stronger antipyretic, analgesic and anti- inflammatory effects; weaker GI reactions; vision damage • piloxicam long-acting anti-inflammatory and analgesic agent; long-term use induces hemorrhage and ulcers in GI tract www.remixeducation.in COX-2 selective anti- inflammatory drugs Meloxicam stronger effect on COX-2 than COX-1 long-acting (t1/2 20 h) weaker GI reactions www.remixeducation.in TNF- inhibitor Etanercept Infliximab Adalimumab They are recombinant proteins that can not orally taken; The long-term safety is not determined. www.remixeducation.in Thank you www.remixeducation.in