This document summarizes analgesics used to treat pain. It describes how analgesics work on the central and peripheral nervous system. It discusses opioid analgesics like morphine which work on mu receptors in the spinal cord. It also discusses non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen, aspirin and paracetamol which inhibit cyclooxygenase enzymes. The document outlines the mechanisms, effects, uses and side effects of various classes of analgesics as well as combination analgesic therapies for treating dental pain.

1. ANALGESICS

2. ANALGESIC
A drug that selectively relieves pain by acting
on CNS or on peripheral pain mechanisms
without significantly altering consciousness

3. ALGESIA or PAIN
It is an illdefined, unpleasent sensation,
usually evoked by an external or internal
noxious stimulus

4. PAIN RECEPTOR
 Pain receptor in our bodies are nerves that transmit pain.
These are free nerve endings located in various body
tissues that respond to thermal, mechanical, & chemical
stimuli.
 When tissue becomes injured, they release chemicals
called prostaglandins and leukotrienes that make the
pain receptor more sensitive and these causing pain.

5. Types of Pain
Visceral
According to
source Somatic
Neuropathic
PAIN
Acute
According to
chronicity Chronic

6. Therapeutic management of pain
Classification:
Peripheral (miscellaneous):
-Causal
-Non causal
Central:
-Narcotic
-Non narcotic

7. Peripheral Analgesic
Causal: Non-causal:
-Treat the cause -Not treat the cause
eg:- atropine Examples:
1- Local anesthetics (for
superficial tumor)
2- Counter-irritant (apply
pain that counteract or
mask the original one e.g.
acupuncture)

8. Central Analgesic
Opioids: NSAIDs:
Morphine & 1- Aspirin
morphine like drugs 2- Paracetamol
3- Diclofenac
4- Piroxicam
5- Ibuprofin
6- Ketoprofin

9. OPIOID ANALGESIC
“Opium” is a Greek word meaning “juice,” or
the exudates from the poppy.
Opium is extracted from poppy seeds (Paper
somniforum)
“Opioid” is a natural or synthetic drug that
binds to opioid receptors producing agonist
effects.

10. Fresh capsule of opium poppy Cut capsule showing latex
exuding from cut

11. Classification
Based on
According to
Chemically receptor
source
occupation
Phenanthrene Agonists Natural opium
group alkaloids
Eg: Morphine Eg: Morphine Eg: Morphine
Benzolisoquino Antagonists Semisynthetic
line group derivatives
Eg: Papaverine Eg: Naloxone Eg: Heroine
Mixed agonist- Synthetic
antagonist opioids
Eg: Nalorphine Eg: Pethidine

12. MORPHINE
• Morphine is the most important alkalloid of
opium.
• Many new opioids have been synthesized but
none of them are superior to morphine as an
analgesic.
• It is the protype of this group.

13. Mechanism of Action
 Opioids exert their major effects by interacting with opioid receptors in the CNS
 Opioids activate 7- transmembrane GPCRs located pre-symaptically and post-symaptically along pain
transmission pathways.
 High densities of opioid receptors known as mu, delta and kappa are found in the dorsal horn of the
spinal cord and higher CNS centers.
 Most currently used opioid analgesics act mainly at mu- opioid receptors
 Morphine acts at kappa receptors in lamina 1 and 11 of the substantia Granulose of the spinal cord
and decreases the release of substance p, which is modulates pain perception in the spinal cord.
 Opioids have an onset of action that depends on the route of administration .
 Opioids causes hyper polarization of nerve cells , inhibition of nerve firing and presynaptic inhibition
of transmitter relea
 Cellular effects of these drugs involve enhancement of neuronal potassium efflux ( hyperpolarizes
neurons and makes them less likely to respond to a pain stimulus ) and inhibition of calcium influx (
decreases neuro- transmitter release from neurons located along the pain transmission pathway )
 Opioids relieve pain both by raising the pain threshold at the spinal cord level and more importantly by altering the brains
perception of pain

15. Pharmacological actions
 Analgesia
 Respiratory depression
 Cough suppression
 Vagal stimulation (bradycardia)
 Sedation & hypnosis
 Hypothermia
 Itching
 Physical & pshycological dependence
 Euphoria
 Histamine release , hypotension….etc

16. Adverse effects
• Morphine can produce a wide range of adverse effects like nausea, vomiting, dizziness,
mental clouding, respiratory depression, constipation, dysphoria, urinary retention, &
hypotension, allergic reactions.
• Tolerance- Repeated administration of morphine results in the development of tolerance to
some of its effects including respiratory depression, analgesia, sedation, etc .
• Dependence- Opium has been a drug of addiction for many centuries. Its ability to produce
euphoria makes it a drug of addiction. Opioids produce both physiological & pshycological
dependence. Manifestations are lacrimination, sweating, yawning, anxiety, restlessness..etc.

17. NSAIDs
Non steroidal anti-inflamatory drugs
are aspirine-type or non-opioid
analgesics.
In addition they have anti-
inflamatory, anti pyretic &
uricosuric properties without
addiction liability.

18. Classification
Non selective COX
inhibitor
• Salicylic acid derivatives. Eg:
aspirine
Selective
• Para aminophenol derivatives.
Eg: paracetamol COX-2
• Pyrazolone derivatives. Eg:
Sphenylbutazone
• Indole acetic acid derivatives. Eg:
inhibitors
sulindac
• Arylacetic acid derivatives. Eg:
diclofenac
• Propionic acid derivatives. Eg:
• Nimesulidde,
ibuprofen
• Anthralinic acid derivatives. Eg;
celecoxib,
flufenamic acid
• Oxicams. Eg: piroxicam rofecoxib…etc
• Alkanones. Eg: nabumetone

19. Mechanism of action
Arachidonic acid
COX-1 COX-2
COX-2
NSAIDs inhibitors
LeukotrienesPr
Prostaglandins
ostaglandins
Primarily support Primarily protect
Primarily mediate
platelet function GI-tract mucosa inflamation, fever, pain

20. Pharmacological actions
• Analgesia
• Antipyretic actions
• Anti-inflamatory actions
• Respiration stimulation
• Metabolic effects
• Immunological effects
• Uric acid excretion
• Blood- delayed clotting time

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

22. Analgesics used in deintistry
• Non opiod analgesics are mostly used for mild to
moderate pain.
• NSAIDs
COX1 & COX2:
Ibuprofen, aspirin, ketrolac, diclofenac
COX-2:
celecoxib, rofecoxib, nimesulide.

23. Acetaminophen
• Dose:
-Adult: 0.5 – 1g every 4-6 hrs.
-6-12 years: 250-500mg every 4-6hrs.
-1-5 years: 150-250mg every 4-6hrs.
• Contraindication:
Renal failure, asthma, liver failure.

24. Nimesulide
• Indication:- Acute pain
• Dose:- 100mg twice a day
• Contraindication:- Renal failure, asthma,
liver failure

25. OPIOIDS
Although opiod as a class are
effective analgesics, some
commonly formulation shows poor
analgesic efficacy for dental pain,
and is not used for their adverse
effects.

26. Tramadol
• Tramadol is a synthetic centraly acting
analgesic indicated to moderate to
moderately severe pain.
• Dose:- 50-100mg every 4-6 hours.
(400mg/day- maximum)

27. Combination!!
• Analgesic monotherapy has shown
equivocal success in treating
dental pain.
• The goal of combining analgesics
with different mechanisms of
action is to use lower doses of the
component drugs.

28. Acetaminophen combination
• Acetaminophen is an effective analgesic for mild pain, but to
manage more severe pain it typically is combined with
codeine or one of its derivatives.
• Acetaminophen 1000mg combined with codeine 60mg.
• Acetaminophen 1000mg combined with oxycodone 10mg.
• Acetaminophen 650mg combined with tramadol 75mg.
• Acetaminophen 500mg combined with hydrocodone 7.5mg.

29. NSAIDs Combination
• Ibuprofen 400mg combined with
codeine 60mg.
• Ibuprofen 400mg combined with
oxycodone 10mg.
• Ibuprofen 400mg combined with
hydrocodone 15mg.

30. THANK YOU