ANALGESICS-DENTAL RELATED

1. Analgesics
-SUYOG MALI
III B.D.S

2. What is Analgesia?
The word analgesia is derived from Greek word
analgetos (an – without ; algesia – pain )
Analgesia simply means the absence of pain without
losing consciousness’

3. Analgesics
“Analgesics are drugs that selectively relieve pain by
acting in the CNS or on the peripheral pain
mechanisms, without altering consciousness”
-

4. History of AnalgesicsHistory of Analgesics
• BC:BC: Ancient Greeks and Romans used salicylate extracts
derived from willow leaves as analgesics and
antipyretics
• Middle Ages: Medicinal herb gardens featured salicylate
containing wintergreen and meadowsweet plants
• 1763: Edward Stone reported on use of willow bark
powder as an anti-inflammatory agent.
• 1853: Von Gerhardt synthesized a crude form of aspirin
(acetylsalicylic acid)
• 1860: Felix Hoffman synthesized pure aspirin

5. continued
• Opiates are one of the oldest types of drugs in history
• Opium is extracted from poppy seeds (Paper
somniforum)
• Undisputed reference to opium found in writings from
the third century BC
• Use of Opium was first recorded in China over 2000
years ago
• Greeks dedicated the Opium poppy to the Gods of Death
(Thanatos), Sleep (Hypnos), and Dreams (Morpheus)
• Sixteenth Century is the first reported use of Opium for
its Analgesic qualities

6. Contnd…
• 1949: The NSAID Phenylbutazone was introduced
• 1963: Indomethacin was introduced
• 1971: Vane and Piper demonstrated that NSAIDs inhibit
prostaglandin production
• 1974: Ibuprofen was introduced
• 1976: Miyamoto et al identified the COX-1 enzyme
• 1989: Simmons et al identified the COX-2 enzyme
• 1999: The COXIBs celecoxib and rofecoxib were introduced
• 2004: Rofecoxib was banned in india due to its cardiotoxic effect .

7. Important medicines include ibuprofen (Motrin), naproxen
(Aleve) and Aspirin.
 Can reduce fever and suppress inflammation.
 Work by blocking cyclooxygenase (COX), an enzyme in
various tissues that produce the chemical mediators which are
the cause for inflammation, related pain, and fever.
 Aspirin besides acting as a pain killer also has anti-platelet
properties, which helps in the treatment for heart attacks and
strokes.

8. Classification of NSAIDs
• Non selective COX inhibitors (conventional NSAID’s)
• Salicylates: Asprin
• Propionic acid derivatives: Ibuprofen, Naproxen,
Ketoprofen, Flurbiprofen
• Anthranilic acid derivative: Mephenamic acid
• Aryl-acetic acid derivatives: Diclofenac
• Oxicam derivatives: Piroxicam, Tenoxicam
• Pyrrolo-pyrrole derivative: Ketorolac
• Indole derivative: Indomethacin
• Pyrazolone derivatives: Phenylbutazone,
Oxyphenbutazone

9. Classification of NSAID’s
contd…
• Preferential COX-2 inhibitors
• Nimesulide, Meloxicam, Nabumetone
• Selective COX-2 inhibitors
• Celecoxib, Rofecoxib, Valdecoxib, Etoricoxib
• Analgesics-antipyretics with poor anti inflammatory
action
• Para aminophenol derivative: Parcetamol
(Acetaminophen)
• Pyrazolone derivatives: Metamizol (Dipyrone),
Propiphenazone
• Benzoxazocine derivative: Nefopam

10. MECHANISM OF ACTION

11. Salicylates -Asprin
• Is acetylsalicylic acid
• Pharmacological actions
• Analgesic, antipyretic, anti inflammatory actions
• Analgesic action is due to prevention of PG mediated
sensitization of nerve endings
• Resets the hypothalamic thermoregulatory centre
• Anti inflammatory at high doses
• Blood
• Long term use of large doses decreases synthesis of
clotting factors in liver

12. Aspirin
• Respiration
• Anti inflammatory doses – stimulates respiration
• Hyperventilation in salicylate poisoning, in doses
higher than this there is respiratory depression
• Acid-base electrolyte balance
• Adults treated with aspirin 4-6g/day stay in a state
of compensated respiratory alkalosis
• Still higher doses can cause respiratory acidosis
• Dehydration occurs in poisoning due to increased
urine output, sweating and hyperventilation
• CVS
• No direct effect in therapeutic doses

13. Aspirin
• GIT
• Aspirin irritates gastric mucosa & causes epigastric
pain, nausea and vomiting
• ‘Acute ulcers, erosive gastritis, congestion and
microscopic hemorrhages
• Metabolic effects
• Chronic use can cause negative nitrogen balance by
increased conversion of protein to carbohydrate.

14. Aspirin
• Pharmacokinetics
• Absorbed from stomach and small intestine
• Precautions and contraindications
• Contraindicated in patients sensitive to it and in peptic
ulcer, bleeding tendencies.
• In chronic liver disease
• Asprin should be stopped 5 days before elective surgery,
dental extraction
• Pregnancy and lactating mothers

15. Asprin
• Adverse effects
• Most important – gastric mucosal damage and peptic
ulceration
• Acute salicylate poisoning
• Uses
• As analgesic
• As antipyretic
• Acute rheumatic fever
• Rheumatoid arthritis
• Osteoarthritis

16. Propionic acid derivatives
• Pharmacokinetics
• Well absorbed orally
• Uses
• Analgesic and Antipyretic and anti-inflammatory
• Soft tissue injuries, tooth extraction, fractures, post
operative pain.
• Rheumatoid arthritis, osteoarthritis and musculoskeletal
disorders… where pain is more prominent than inflammation

17. Anthranilic acid dervative
• Mephenamic acid-
• Inhibits COX & antagonises certain actions of PG’s
• Exerts peripheral as well as central analgesic action
• Pharmacokinetics
• Oral absorption is slow but complete
• Adverse effects - Diarrhoea
• Uses
• Muscle, joint and soft tissue pain
• Effective in dysmenorrhoea

18. Beneficial actions due to PGBeneficial actions due to PG
synthesis inhibitionsynthesis inhibition
• Analgesia
• Anti pyresis
• Anti inflammatory
• Anti thrombotic

19. Routes of analgesic
administration
• Oral
• Intramuscular Injection
• Intravenous Injection
• Other routes
• Transdermal
• Fentanyl patch
• Sublingual
• Morphine

20. Opioid analgesics

21. Classification of opioids
• Natural opium alkaloids
• Morphine, codeine
• Semi synthetic opiates
• Diacetylmorphine (heroin), pholcodeine
• Synthetic opioids
• Pethidine (meperidine), fentanyl, methadone,
dextropropoxyphene, tramadol

22. Morphine
• Alkaloid of opium
• Widely used
• Pharmacological actions
• CNS
• Analgesia
• Strong analgesic
• Nociceptive pain arising from peripheral pain
receptors is better relieved than neuritic pain
• Reactions associated with intense pain –
apprehension, fear are also depressed

23. Morphine
• CNS
• Sedation
• Drowsiness and indifference to surroundings as well
as to own body , ataxia and apparent excitement also
occur
• Higher doses produce sleep and coma
• Mood and subjective changes
• Calming effect
• Loss of apprehension, feeling of detachment,mental
clouding and inability to concentrate

24. Morphine
• Respiratory and cough centres
• Depresses Repiration and Cough centre
• Temperature regulating and vasomotor centre
• Depressed
• CTZ(chemoreceptor trigger zone), vagal centre &
certain cortical areas are stimulated
• GIT
• Constipation is a prominent feature

25. Morphine
• Neuro-endocrine
• Enhances ADH release and so urine volume is reduced
• Causes sympathetic stimulation – mild hypoglycemia
• CVS
• Causes vasodilation
• Cardiac work is consistently reduced due to decrease in
peripheral resistance

26. Morphine
• Pharmacokinetics
• Oral absorption is unreliable – high and variable first pass
metabolism
• Freely crosses placenta, affects foetus more than the mother
• Adverse effects
• Mental clouding, sedation and lethargy
• constipation
• Acute morphine poisoning
• Human lethal dose is 250mg .
• Death is due to respiratory failure

27. Morphine
• Tolerance and dependence
• Partly pharmacokinetic (enhanced rate of metabolism) but
mainly pharmacodynamic (cellular tolerance)
• Treated by substitution with oral methadone
Precautions and contraindications
• Infants and elderly
• Bronchial asthma(wheezing)
• Head injury
•

28. Codeine
• Is methyl morphine
• Less potent than morphine (1/10th
as analgesic)
• Is more selective cough suppressant

29. Pethidine
• Synthesized as an atropine substitute
• Interacts with opioid receptors (mu)
• Similar to morphine in most of its properties
• Uses
• As analgesic (substitute to morphine)
• In pre anaesthetic medication

30. Methadone
• Chemically dissimilar but pharmacologically similar
to morphine
• Used
• primarily as substitution therapy for opioid
dependence
• Also in methadone maintenance therapy

31. Opioids in dental pain
• Opioids are less effective and suitable than NSAID’s for
dental pain
• Mostly used as additional drugs with NSAID’s to boost
their analgesic effect
• Among opioids oral codeine is most suitable
• Oral tramadol and pentazocine are alternatives

32. Analgesics & Medical conditions
• NSAIDs should be given in 2nd
triemister of pregnancy and
opioids should be avoided .
• Paracetamol is the safest drug to use in pregnancy
• Aspirin & Ibuprofen should not be given in asthmatic
patients
• Aspirin & Paracetamol should not be given in
nephropathy(affected state of kidney)
• Codein should not be used in renal dysfunction while
fentanyl & methadone are safe .

45. THANKY
OU