Analgesics and anti inflammatory drugs

analgesics.
Nsaids.
anti-inflammatory.

1. Analgesics and Anti-inflammatory drugs DR Bhaumik Thakkar Part-1 P.G Dept of Periodontology and Implantology

2. INTRODUCTION ANALGESICS A drug that selectively relieves pain by acting in CNS or on peripheral pain mechanism, without significantly altering consciousness. ANAESTHESIA Anaesthesia means loss of sensation. Anaesthetic agent is one which bring about loss of all modalities of sensation, particularly pain, along with a reversible loss of consciousness. PAIN (ALGESIA) An unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage.

3. CLASSIFICATION Divided into 2 groups: 1. Opioid Analgesics -Narcotics/Morphine like analgesics 2. Non Opioid Analgesics -NSAIDs/Non narcotic/aspirin like analgesics

4. History of Opioid. Obtained from poppy { papaver somniferous } capsule called “ opium ”, known from earliest times. Mentioned in Eber’s papyrus[1500BC] and in writings of theophrastus [300BC] and Galen [ 2 nd century AD ] Serturner ,a pharmacist isolated the active principle of opium in 1806 and named it ‘ morphine ’ after a Greek god of dreams Morpheus .

5. OPIOID ANALGESICS Natural Opium alkaloids Morphine & Codeine. Semi synthetic opiates Diacetylmorphine oxymorphone Pholcodeine Synthetic opioids Pethidine Fentanyl Methadone Dextropropoxyphene Ethoheptazine Tramadol

6. NON OPIOID ANALGESICS & NSAIDs Analgesic and Anti inflammatory NON-SELECTIVE COX INHIBITORS Salicylates – Aspirin, Salicylamide, Benorylate, Diflunisal. Pyrazolone derivatives – Phenyl butazone, Oxyphenyl-butazone. Propionic acid derivatives – Ibuprofen, Naproxen, Ketoprofen, Fenoprofen, Flurbiprofen, Oxaprozin. Indole derivatives – Indomethacin, Sulindac. Anthranilic acid derivative – Mephanimic acid, Flufenamic acid. Aryl acetic acid derivative – Diclofenac, Tolmetin.. Oxicam derivative – Piroxicam, Tenoxicam. Pyrrolo pyrrole derivatives – Ketorolac, Feprazone.

7. B. Preferential COX-2 inhibitors - Nimesulide - Meloxicam - Nabumetone C. Selective COX-2 inhibitors - Valdecoxib - Celecoxib - Rofecoxib

8. D. Analgesics with poor Anti inflammatory action- Paraminophenol derivative - Paracetamol (Acetaminophen) Pyrazolone derivative - Metamizol, Propiphenazone Benzoxazocine derivative - Nefopam

9. Pharmacological Actions 1.CNS – Depressant and stimulant action 2.CVS – Causes vasodilation 3. GIT – Constipation 4. Smooth muscles – Increased ureter contraction, Broncho constriction 5. ANS – Mild hyperglycemia

10. Adverse effects Analgesics doses are usually well tolerated but anti-inflammatory doses are usually associated with adverse effects whed used for a long period. G.I tract:- Epigastric distress, nausea, vomiting, erosive gastritis, peptic ulcer, increase occult blood loss in stools are common Allergic reactions are not common and may be manifested as rashes, photo sensitivity..etc Haemolysis Nephrotoxicity Reye’s syndrome Salicylism Acute salicylate intoxication

11. Functions of NSAIDs Analgesia – PGs induce hyperalgesia by affecting the transducing property of free nerve endings – stimuli that normally do not elicit pain are able to do so . NSAIDs do not affect the tenderness induces by direct application of PGs but block the pain sensitization mechanism induced by bradykinin . Antipyresis – NSAIDs reduce body temperature in fever , but do not cause hypothermia in normothermic individuals . NSAIDs block the action of pyrogens but not that of PGE2 injected into the hypothalamus .

12. Anti - inflammatory – Due to inhibition of PG synthesis at the site of injury. Inflammatory cells express integrins and selectins and NSAIDs act by inhibiting some of these molecules . Growth factor like GM-CSF, IL-6, lymphocyte transformation factor may also be affected. Stabilization of leukocyte lysosomal membrane and antagonism of certain actions of kinin may be contributing to NSAIDs action. Antiplatelet aggregatory – NSAIDs inhibit synthesis of both proaggregatory { TXA2 } and antiaggregatory { PGI2 } prostanoids , but effect on platelet aggregation TXA2 predominated producing therapeutic doses of most NSAIDs inhibit platelet aggregation : bleeding time is prolonged .

13. Ductus arteriosus closure- Administration of NSAIDs in late pregnancy has been found to promote premature closure of ductus in some cases. Parturation – Sudden spurt of PG synthesis by uterus probably triggers labor and facilitates its progression .NSAIDs has the capacity to retard and delay labor .

14. Gastric mucosal damage – Gastric pain , mucosal damage are produced by all NSAIDs .Inhibition of synthesis of PG { PGE2 , PGI2 } is clearly involved . Deficiency of PGs reduces mucus and HCO3- secretions , tends to enhance acid secretion and may promote mucosal ischaemia . Thus, NSAIDs enhance aggressive factors and contain defencive factors in gastric mucosa – which are ulcerogenic . PCM, a very weak inhibitor of COX is practically free of gastric toxicity and selective COX – 2 inhibitor are safer..

15. Anaphylactoid reaction – Aspirin PPts asthma , angioneuretic swellings , urticaria or rhinitis in certain susceptible individual . These subjects react similarly to chemically diverse NSAIDs ,ruling out immunological basis for the reaction .

16. Uses Acute or chronic conditions where pain and inflammation are present. (Rossi, 2006) Rheumatoid arthritis Osteoarthritis Inflammatory arthropathies (e.g. ankylosing spondylitis , ) Acute gout Dysmenorrhoea Metastatic bone pain Headache and migraine Postoperative pain Mild-to-moderate pain due to inflammation and tissue injury Pyrexia Renal colic They are also given to just born infants whose ductus arteriosus is not closed within 24 hours of birth

17. Prostaglandins synthesis inhibiton Membrane phospholipids Phospholipase A Arachidonic acid Cyclo oxygenase PG G 2 + PG H 2 Isomerases Thromboxane sythetase Prostacyclin synthetase PG E 2 , PG D 2 , PG F TX A TX B 2 PG I 2 PG E 2 , PG D 2 , PG F TX A 2

18. Physiological Functions of Prostaglandins - Pain: PGI 2 and PGE 2 sensitize nerve endings to bradykinin, histamine - Inflammation: PGI 2 , PGD 2 and PGE 2 are vasodilators (edema, erythema ) - Protection of the gastric mucosa: PGI 2 - Maintenance of renal blood flow: PGE 2 - Fever: PGE 2 - Platelets: PGI 2 and PGD 2 inhibit platelet aggregation. TXA 2 stimulates platelet aggregation - Uterus: PGD 2 contracts uterus - Other:PGE 2 keeps ductus arteriosus open following birth

19. COX-2 Hypothesis (1990s) Normal Tissue Inflammation Site Physiolgical Prostaglandin Production Pathological Prostaglandin Production COX-1 Constitutive COX-2 Inducible Arachidonic Acid Normal Functions Inflammation, pain, fever NSAIDs Cytokines Growth factors +

20. Role of PGs in inflammation By 2 roles: Promote development Modulate and regulate inflammatory cell function { Gordon et al 1976 } PG can induce pain , edema , redness and vasodilation when they are induced by other mediators . PG inhibits lysosomal enzyme release during phagocytosis , enhances chemotaxix , chemokinesis { Estensen et al 1973 } Inhibit clonal proliferation of macrophages stem cells migration of macrophages On lymphocytes it supress cell transformation { Mihas 1975 }

21. Role in Bone Resorption In number of ways and may induce bone resorption by facilitating the release of osteoclasts activating factor from lymphocytes { Yoneda & Mundy 1979 } Inhibit bone collagen formation which result in inhibition of the repair of resorbed bone { Raisz & Koolemans – Beynen 1974 } Role in periodontal destruction – Production of arachidonic acid metabolites : Recently the role of host’s immuno inflammatory system is understood . After activation of inflammatory cells in the periodontium by bacteria , phospholipids in the plasma membrane of cells become available for actions by phospholipase . This leads to free arachidonic acid in the area {AAP 1992}

22. INDICATIONS OF NSAIDS IN DENTISTRY Irreversible pulpitis Apical periodontitis Acute alveolar abscess Infected cyst Sinusitis TMJ Arthritis MPDS After tooth extraction Dry socket Recurrent apthous ulcers Lichen planus Agranulocytosis Cyclic neutropenia

23. GENERAL CONTRAINDICATIONS Ulcer Asthma Patient with nasal polyp Diabetes Gout Influenza (Reye’s syndrome) Hypo coagulation state Chronic allergic disorders Chronic liver disease Renal failure Salicylate allergy Breast feeding mothers Pregnancy

24. NSAIDs as Host M odulation Therapy Treatment concept that aims to reduce tissue destruction and stabilize or even regenerate the periodontium by modifying or downregulating destructive aspects of host response and upregulating protective or regenerative responses. (CARRANZA) HMTs are systemically or locally delivered pharmaceuticals that are prescribed as part of periodontal therapy and are used as adjuncts to conventional periodontal treatments.

25. HMTs offer the opportunity for modulating or reducing this destruction by treating aspects of the chronic inflammatory response. HMTs do not “switch off” normal defense mechanism or inflammation; instead, they ameliorate excessive of pathologically elevated inflammatory processes to enhance opportunities for wound healing.

26. The Effect of Non-Steroidal Anti-Inflammatory Drugs on Bleeding During Periodontal Surgery Journal of Periodontology July 2005, Vol. 76, No. 7, Pages 1154-1160 15 medically healthy subjects (seven males and eight females), each having two sites requiring periodontal surgery of similar complexity, type, and duration, were selected for the study. The subjects were instructed to take ibuprofen prior to one of the surgeries. A standard bleeding time and papillary bleeding index score were recorded at initial consultation, and prior to the first and second surgeries. The volume of aspirated blood was measured during each surgery by subtracting the amount of water used for irrigation from the total volume of fluid (blood + irrigation water) collected at 15-minute intervals during the surgery.

27. In vivo models First evidence that NSAID block PG production in gingival tissue was produced by Gomes in 1976 , who demonstrated that inflammed gingival fragments taken from monkeys consistently release PG into the culture medium , and that the pyrazole compd indomethacin reduced the amount of PG released by at least 90% . The NSAID indomethacin , ibuprofen , piroxicam , flurbiprofen , and zomepirac sodium have significant inhibitory effect on the production of PG.

28. NSAIDS block PGE2 production , thereby reducing inflammation & inhibiting osteoclast activity in periodontal tissue Studies have shown that systemic NSAIDS such as indomethacin , flurbiprofen & naproxen administered daily for upto 3 yrs significantly slowed the rate of alveolar bone loss compared with placebo However daily administration for extended period is necessary for periodontal benefits

29. ASPIRIN Acetylsalicylic acid Pharmacological actions Analgesic, antipyretic, antiinflammatory actions Metabolic effects: Blood sugar may decrease, plasma free fatty acid & cholesterol levels reduced Respiration: Hyperventilation in salicylate poisoning Acid base & electrolyte balance: Compensated respiratory alkalosis CVS: Vasodilation, increase in cardiac output GIT: Epigastric distress, nausea & vomiting Blood: Prolongs bleeding time

30. ADVERSE EFFECTS : Nausea, vomiting, epigastric distress, increased blood loss in stools Rashes, fixed drug eruptions, urticaria , rhinorrhea , angioedema , asthma, anaphylactoid reaction Salicylism – dizziness, tinnitus, vertigo, impairment of hearing & vision, excitement & mental confusion, hyperventilation & electrolyte imbalance Acute salicylate poisoning: Fatal dose in adults 15-30g, lower in children

31. USES : Analgesic Antipyretic Acute rheumatic fever Rheumatoid arthritis Osteoarthritis Postmyocardial infarction Patent Ductus Arteriosus Familial colonic polyposis Prevention of colon cancer Treatment of Bartter’s syndrome

32. Precautions & Contraindications : Peptic ulcer Bleeding tendencies Children with chicken pox or influenza Chronic liver disease Diabetics Pregnancy Breast feeding mothers Dose - 0.3-0.6 g 4-6 hrly orally

33. Commercially available as: Aspirin: 350 mg tab. Disprin : 350mg tab. Colsprin : 100, 325,650mg tab. Ecosprin : 75, 150, 325mg tab.

34. Dental consideration in a patient who is on aspirin therapy BT CT PT INR

35. INDOMETHACIN Indole derivative Potent inhibitor of PG synthesis & suppresses neutrophil motility Well absorbed orally & t ½ is 2-5 hrs Adverse effects: Gastric irritation, nausea, anorexia, gastric bleeding & diarrhoea , frontal headache, dizziness, ataxia, mental confusion, depression, psychosis, leukopenia , rashes, increased risk of bleeding Contraindicated in machinery operators, drivers, psychiatric patients, epileptics, kidney disease, pregnant women & children Dose: 25-50mg BD-QID Commercially available as- Idicin , Indocap , Indoflam : 25mg, 75mg tab

36. IBUPROFEN Propionic acid derivative Adverse effects: Gastric discomfort, nausea & vomiting Headache, dizziness, blurring of vision, tinnitus & depression Avoided in pregnancy, peptic ulcer patient & asthmatic patients

37. USES: Analgesic & Antipyretic Rheumatoid arthritis, osteoarthritis, musculoskeletal disorders Soft tissue injuries, fractures, vasectomy, tooth extraction Postpartum & postoperatively : suppress swelling & inflammation Dose: 400-800 mg TDS Comercially available as- Brufen , Emflam , Ibusynth : 200, 400, 600mg tab. Ibugesic : 100mg, 400 mg tab.

38. DICLOFENAC SODIUM Aryl-acetic acid derivative Well absorbed orally Plasma t ½ - 2 hrs Adverse effects: Epigastric pain, nausea, headache, dizziness, rashes Uses: Rheumatoid arthritis, ankylosing spondylitis , dysmenorrhea , post traumatic & post inflammatory conditions Dose: 50mg TDS, then BD oral, 75mg deep i.m Commercially available as: Voveran , Diclonac , Movonac : 50 mg tab. Diclomax : 25, 50 mg tab.

39. KETOROLAC Pyrrolo-pyrrole derivative Potent analgesic & modest anti inflammatory Rapidly absorbed after oral & i.m administration Plasma t ½ is 5-7 hrs Adverse effects: Nausea, abdominal pain, dyspepsia, ulceration, loose stools, drowsiness, headache, dizziness, nervousness, pruritis , pain & fluid retention Not be given to patients on anticoagulants

40. USES: Postoperative & acute musculoskeletal pain: 15-30 mg i.m or i.v every 4-6 hrs Used for renal colic, migraine, pain due to bony metastasis Orally in a dose of 10-20 mg 6 hrly . Commercially available as – Ketorol , Zorovon , Ketanov , Torolac : 10mg tab.

41. NIMESULIDE Preferential COX-2 inhibitors Used for short lasting painful inflammatory conditions like sports injuries, sinusitis, ear nose throat disorders, dental surgery, bursitis, low backache, dysmenorrhoea , post operative pain, osteoarthritis & for fever Completely absorbed orally, excreted in urine, t ½ of 2-5 hrs

42. Adverse effects: - Epigastralgia , heart burn, nausea, loose motions, rash pruritus . - Hematuria & fulminant hepatic failure in few cases Useful in asthmatics, bronchospasm or intolerance to aspirin & other NSAIDs Dose: 100 mg BD Commercially available as- Nimulid , Nimegesic , Nise , Nobel, Nimodol : 100mg tab.

43. Conclusion Analgesics are definitely useful in reducing pain & improving the quality of life but have their own spectrum of adverse effects. No single drug is superior to all others for every patient. Choice of drug is inescapably empirical .