Non-steroidal%20Anti-inflammatory%20Drugs - PowerPoint PPT Presentation

About This Presentation
Title:

Non-steroidal%20Anti-inflammatory%20Drugs

Description:

Non-steroidal Anti-inflammatory Drugs Dr.B.V.Venkataraman Professor in Pharmacology International Medical School Faculti Perubatan, New BEL Rd Bangalore - 560054 – PowerPoint PPT presentation

Number of Views:191
Avg rating:3.0/5.0
Slides: 21
Provided by: G3151
Category:

less

Transcript and Presenter's Notes

Title: Non-steroidal%20Anti-inflammatory%20Drugs


1
Non-steroidal Anti-inflammatory Drugs
  • Dr.B.V.Venkataraman
  • Professor in Pharmacology
  • International Medical School
  • Faculti Perubatan, New BEL Rd
  • Bangalore - 560054
  • Venkataraman_bv_at_yahoo.com

2
COX
3
Physiological stimulus Inflammatory
stimulus
Macrophages/other cells
COX-1 Constitutive
Cox-2 Induced
Other inflammatory mediators
Proteases
PGs
TXA2 Platelets
PGI2, endothelium Stomach mucosa etc
PGE2, Kidney etc
INFLAMMATION
4
(No Transcript)
5
Classification of NSAID
  • COX-1 and COX-2 inhibitors
  • Salicylates Aspirin
  • Para-aminophenols Phenacetin, Paracetamol.
  • Pyrazolons Phenylbutazone
  • Indoles Indomethacin, Sulindac, Tolmetin,
    Ketorolac.
  • Phenylacetates Diclofenac
  • Propionates Ibuprofen, Ketoprofen,
  • Fenamates Flufenamic acid and Mefenamic acid.
  • Oxicams Piroxicam

6
Classification of NSADs (contd)
  • COX-2 inhibitors (Coxibs)
  • Valdecoxib, etorocoxib
  • COX-3 inhibitors
  • Paracetamol
  • Miscellaneous COX Inhibitors
  • Nimesulide, Meloxicam, Etodolac etc
  • Drugs do not inhibit PGs
  • Nefopam

7
SALYCILATES
  • Source bark of willow (used in malaria)
  • Now it is commercially synthesised.
  • Salicylic acid
  • Sodium salicylate
  • Acetyl salicylic acid (aspirin)
  • Methyl salicylic acid (oil of winter green)
  • Diflunisal is a derivative of aspirin.

8
SALICYLATES
  • LOCAL ACTIONS
  • Irritants
  • Salicylic acid Keratolytic, used in ring worm
    infection
  • Methyl salicylate counter irritant in relieving
    joints and muscular pain

9
Aspirin systemic effects
  • Analgesic

Aspirin
10
Types of Analgesis
  • Two types
  • Narcotic analgesics
  • Relieve pain and produce sedative/hypnotic
    effect e.g. morlphine, pethidine
  • 2. Non-narcotic analgesics
  • Relieve pain with out affecting the
    consciousness e.g. aspirin, paracetamol

11
Systemic actions of aspirin
  • Antipyretic action Inhibition of central PG
  • Antiplatelet action

12
(Anti inflammatory action)
13
Systemic actions of aspirin
  • TxA2 is present in platelets
  • At any dose anti-platelet aggregation (inhibiting
    TXA2)
  • At low dose PGI2 not inhibited
  • At high dose PGI2 is inhibited.
  • PGI2 vasodilator and anti-platelet aggregation.
  • Action is irreversible.
  • Duration 8-10 days (life of platelet)

14
Systemic actions of Salicylates
  • Renal effect PGE2 (vasodilator) coordinate with
    angiotensin-II. Chronic NSAIDs leads to
    inhibition of PGE2 and vasoconstriction.
  • Respiration directly and indirectly. O2 leads to
    CO2 which stimulates respiratory centre. These
    events leads to hyper ventilation.
  • Low dose decrease the uric acid level. High dose
    uricosuric effect.

15
Pharmacokinetics
  • Well absorbed from stomach and small intestine
  • Empty stomach and acid medium helps absorption
  • Deacetylation in gut wall, liver, plasma other
    tissues after absorption.
  • Protein binding 80
  • Conjugated with glycine.
  • 1/10 is excreted in active form which can be
    enhanced with alkalinisation.

16
Side effects of aspirin
  • Intolerance (rare) rashes, urticaria, asthma
    etc.
  • Gastric irritation
  • Hypoprothrombinemia Vit K is antidote
  • Reyes syndrome Children prescribed for viral
    fever. Syndrome consists of liver dysfunction
    (fatal)
  • Salicylism headache, dizziness, vertigo,
    difficulty in hearing and dimness of vision. The
    symptoms are reversible once the drug is
    withdrawn.

17
Treatment of acute salicylate poisoning
  • Symptomatic treatment
  • Patent airway
  • Hyperthermia reduced by external cooling.
  • Dehydration should be corrected.
  • Vitamin K should be administered.
  • Metabolic acidosis is corrected by NaHCO3 which
    also promotes renal excretion of salicylates.
  • Forced diuresis is done by administration of
    furosemide (40 mg) in the infusion fluid.
  • Dialysis is done in renal failure.

18
Clinical uses of Salicylates
  • Keratolytic and antifungal salicylic acid
  • Counter irritant Methyl salicylic acid
  • Acute rheumatic fever Streptococcal infection
    induces antibodies reacting with lymphocytes.
    These antibodies react with heart valves and
    myocardium.
  • Treatment
  • a. Penicillin for the streptococcal infection.
  • b. Aspirin (5-8 g in divided doses) for the
    inflammation.
  • c.corticosteroids can also be given.

19
Clinical uses of aspirin
  • Arthritis and fibromyositis In rheumatoid
    arthritis, aspirin at 5-6 g in divided doses is
    advised.
  • Ischaemic heart disease In low doses (100 mg
    daily) aspirin is given to prevent platelet
    aggregation.
  • Pain headache, fever, dysmenorrhoea etc.
  • For closure of patent ductus arteriosus.

20
Drug interaction
  • Aspirin displaces oral anticoagulants, oral
    antidiabetics etc.
  • Interfers with uric acid excretion (analgesic
    dose inhibit)
  • Decreases the diuretic actions (thiazides and
    furosemide)
  • Reduces the K sparing action of spiranolactone.
Write a Comment
User Comments (0)
About PowerShow.com