NSAIDs in endodontics for pain management

NSAIDs in endodontics for pain management

1. Nsaids in endodontics SHORT TOPIC PRESENTATION Eldho George Junior resident

2. contents Introduction Brief explanation of the pain pathway Commonly used nsaid’s Conclusion reference

3. introduction The word pain is derived from the Latin word Peone and the Greek word Poine meaning penalty or punishment Pain is defined by The International Association for the Study of Pain (IASP ); as an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage

4. What are analgesics ? A drug that selectively relieves pain by acting on the CNS or peripheral pain mechanisms, without significantly altering consciousness

5. Brief explanation of the pain pathway Somatosensory cortex is the pain perception area in the brain

6. Following a tissue injury chemical mediators ( like prostaglandins) are released from damaged cells as well as from the inflammatory mediators like neutrophils,macrophages etc

7. The sensory nerves adjacent to the injury sites will get stimulated by these prostaglandins, thus creating a pain impulse This pain impulses are carried to the dorsal horn of spinal cord by the first order neuron

8. First order neuron

9. In the dorsal horn of spinal cord, the first order neuron relays the impulses to the second order neuron and this neuron will cross over (decussate) to the opposite side and enters the spinothalamic tract

10. Second order neuron

11. The second order neuron will ascend up through the rest of the spinal cord and the brain stem and terminate in the thalamus (gateway of impulses) In thalamus second order neuron synapse with the third order neuron . This third order neuron will finally relay the impulses to the appropriate region of the somatosensory cortex where it is perceived

12. Third order neuron

13. Nsaid’s Stands for ‘non steroidal anti inflammatory drugs’ Primarily act on peripheral pain receptors and CNS Increase pain threshold

14. Basic physiology Prostaglandin’s Any of a group of potent hormone like substances which are produced in various mammalian tissues, derived from arachidonic acid and mediate wide range of physiological functions such as control of inflammation, contraction of uterine smooth muscle, maintenance of blood pressure.

15. Formation of prostaglandins During injury,the injured/ inflammatory cells convert phospholipid in their cell membrane with the help of the phospholipase a2 (PLa2) into arachidonic acid.

16. Prostaglandin production depends on the activity of COXs (cyclooxygenases), bifunctional enzymes that contain both cyclooxygenase and peroxidase activity and which exist as distinct isoforms referred to as COX-1 (cyclooxygenase-1) and COX-2 (cyclooxygenase-2)

17. Cyclooxygenase-1 (COX-1), expressed constitutively in most cells, is the dominant source of prostanoids that subserve housekeeping functions, such as gastric epithelial cytoprotection and homeostasis  2. Cyclooxygenase-2 (COX-2), induced by inflammatory stimuli, hormones and growth factors, is the more important source of prostanoid formation in inflammation and in proliferative diseases, such as cancer.

18. Classification of nsaid 1. non selective cox inhibitor 2. preferential cox 2 inhibitor 3. selective cox 2 inhibitor 4. analgesics, antipyretics, with poor anti inflammatory action

19. Non selective cox inhibitor 1 . salicylates aspirin 2. Propionic acid derivatives ibuprofen naproxen ketoprofen flurbiprofen

20. 3. fenamate mephenamic acid 4. enolic acid derivative piroxicam tenoxicam

21. 5. acetic acid derivative ketorolac indomethacin nabumetone 6.pyrazolone derivative phenylbutazone oxyphenbutazone

22. Preferential cox 2 inhibitor Nimesulide Diclofenac Aceclofenac Meloxicam etodolac

23. Selective cox 2 inhibitor Celecoxib Etoricoxib parecoxib

24. Analgesics antipyretics with poor anti-inflammatory action 1. paraaminophenol derivative paracetamol /acetaminophen/Tylenol 2. pyrazolone derivative metamizole propyphenazone 3. benzoxazocine derivative nefopam

25. ASPIRIN irreversible cox inhibitor Aspirin dosage 1. 50 mg – 362 mg/day – antiplatelet action 2. 2 – 4 gm - anti inflammatory action m/c side effect of aspirin is erosion of gi mucosa

26. Aspirin is contraindicated in children with viral fever due to the fear of reye’s syndrome Overdosage of aspirin is termed as salicylism Treatment of salicylism is sodium bicarbonate

27. ibuprofen They are indicated in soft tissue injuries, fractures, tooth extraction and postoperatively suppress swelling and inflammation. Concurrent treatment with ibuprofen has been found to prevent irreversible COX inhibition by low dose aspirin.

28. Thus, it may antagonize the antiplatelet and cardioprotective effect of low dose aspirin . Dosage : 400 -600 mg tds

29. Side effects : Hypersensitivity syndrome associated with Ibuprofen is a host-dependent drug reaction that is idiosyncratic in nature and can cause Steven Johnson Syndrome. Gastric ulcers

30. Mefenamic acid Dosage 250 – 500 mg Used primarily as an analgesic in muscle, joint and soft tissue pain where strong anti inflammatory reaction is not needed.

31. Diclofenac sodium Diclofenac is one among the most extensively used NSAID Employed in rheumatoid and osteoarthritis, bursitis, ankylosing spondylitis, toothache, dysmenorrhoea, post-traumatic and postoperative inflammatory condition.

32. Affords quick relief of pain and wound edema . Also available as a topical patch for strains, sprains and contusions. dosage : 50 mg tds oral

33. piroxicam It is a reversible inhibitor of COX; inhibits platelet aggregation— prolonging bleeding time Piroxicam is suitable for use as short-term analgesic as well as long-term anti inflammatory purposes.

34. t ½ is long – nearly 2 days Dosage : 20 mg od

35. ketorolac Potent analgesic with modest antiinflammatory activity. Ketorolac has been rated superior to aspirin (650mg), paracetamol (600 mg) and equivalent to ibuprofen (400 mg).

36. Continuous use for more than 5 days is not recommended. It should not be given to patients on anticoagulants Dosage : 10 – 20 mg

37. nimesulide Used primarily for short-lasting painful inflammatory conditions like sports injuries, sinusitis and other ear-nose-throat disorders, dental surgery. Fulminant hepatic failure have been associated with nimesulide and it has been withdrawn in many countries.

38. Dosage : 100 mg bd

39. etoricoxib Suitable for once a day treatment of acute dental surgery pain and similar conditions, without affecting platelet function or damaging gastric mucosa. Found it to be as effective as naproxen or diclofenac , without affecting COX-1 activity in gastroduodenal mucosa.

40. Dosage : 60 – 120 mg od

41. paracetamol Most commonly used ‘over-the-counter’ analgesic for headache, mild migraine, musculoskeletal pain, dysmenorrhoea, etc. It is relatively ineffective when inflammation is prominent .

42. It is one of the best drugs to be used as antipyretic, especially in children (no risk of reye’s syndrome) Can be used in all age groups (infants to elderly), pregnant/lactating women, in presence of other disease states and in patients in whom aspirin is contraindicated.

43. It does not have significant drug interactions Adverse effects : Acetaminophen overdose can cause hepatotoxicity.

44. Severe hepatotoxicity has been reported even after therapeutic doses in patients with risk factors such as : 1. chronic alcohol consumption, 2. human immunodeficiency virus infection, and 3. hepatitis C virus infection

45. nitroxyparacetamol Is a new potent no releasing version of paracetamol that has analgesic and anti inflammatory properties The described mechanism of action in the spinal cord may differ from that of paracetamol and there is evidence that nitroxyparacetamol may be less hepatotoxic Keeble JE, Moore PK. Pharmacology and potential therapeutic applications of nitric oxide-releasing non-steroidal anti-inflammatory and related nitric oxide-donating drugs. Br J Pharmacol 2002; 137: 295–310

46. Adverse effects of nsaid’s Minor side effects include nausea, vomiting, diarrhoea, dizziness, and headache. Serious side effects include prolonged bleeding after surgery, kidney failure, and gastrointestinal and cardiovascular adverse effects.

47. Long-term use of NSAIDs in combination with other NSAIDs or acetaminophen may lead to nephrotoxicity, and must be avoided. Ibuprofen has the lowest risk Diclofenac and Naproxen have intermediate risks Piroxicam and Ketorolac carry the greatest risk.

48. Route’s of administration Severe local reactions are associated with intramuscular injection of NSAIDs Necrotizing fasciitis is a life-threatening infection of the superficial muscle fascia and the adjacent deep layer of subcutaneous tissue that has been reported with the injection of intramuscular diclofenac and ketorolac

49. The iv route was also reported to increase the risk of postoperative bleeding Parenteral route has the same risks of gastrointestinal toxicity as the oral route. The only exception is the topical route, which is not associated with any of the gastrointestinal effects .

50. 1 . Mild-to-moderate pain with little inflammation: paracetamol or low-dose ibuprofen 2. Postoperative or similar acute but shortlasting pain: ketorolac, ibuprofen, diclofenac, nimesulide or aspirin. 3. Acute musculoskeletal, osteoarthritic, injury associated pain: paracetamol, ibuprofen or diclofenac.

51. Gastric intolerance to traditional NSAIDs or predisposed patients : a selective COX-2 inhibitor or paracetamol. History of asthma or anaphylactoid reaction to aspirin/other NSAIDs: nimesulide , COX-2 inhibitor

52. Topical preparations of nsaid Diclofenac 1% gel : vovaran emulgel , relaxyl gel, diclonac gel Ibuprofen 10% gel : ribufen gel Naproxen 10% gel : naprosyngel Flurbiprofen 5% gel : froben gel Nimesulide 1% gel : nimulid trans gel, zolandin gel, nimegesic t gel Piroxicam 0.5% gel : dolonex gel, movon gel, pirox gel, minicam gel

53. Drug interactions

54. Combination of nsaid’s with enzymes Protease enzymes belonging to family metalloprotease, have been successfully tested for their anti inflammatory properties, which include trypsin, chymotrypsin and serratiopeptidase

55. To overcome their destruction in stomach by hydrolysis, these tablets are given in enteric coated dosage form and in combinations

56. Nsaid’s and pregnancy

57. conclusion • From a dentists’ perspective, we are able to choose from a plethora of medications to provide patients with pain relief, but trying to judge the relative efficacy of analgesics is not easy • One must remember that the best means of managing pain is to remove the source of pain as quickly as possible.

58. Management of pain is challenging part of dental treatment, sometimes pain is a major symptom after many dental procedures especially for endodontists.

59. references Guyton and Hall Physiology 14th Edition Essentials of Pharmacology for Dentistry, KD Tripathi Review of pharmacology, gobind rai garg