3. SPECIFIC OBJECTIVES
• Define pain, pain pathways, types of
pain
• Types of analgesics
• Mechanism of action
• Indications
• Contraindications
• Adverse effects
• Nursing responsibilities
4. ALGESIA(PAIN):is an unpleasant sensory and
emotional experience associated with actual or
potential tissue damage or described in terms of
such damage.
ANALGESIC: A drug that selectively relieves
pain by acting in the CNS or on peripheral pain
mechanisms, without significantly altering
consciousness
7. TYPES OF PAIN
ACUTE: It is of short duration but it gradually
resolves as the injured tissue heal.
E.g.injury or trauma
CHRONIC: persistent pain that lasts week to
years
E.g. pain may be caused by inflammation or
dysfunctional nerves.
8. BASED ON ETIOLOGY
NOCICEPTIVE PAIN: Result of activation of
sensory(afferent)receptors (nociceptors)by mechanical,
thermal, chemical stimuli
Functional,physiologic or normal pain
NEUROPATHIC PAIN: Pain resulting from damage to
peripheral nervous or central nervous system tissue or
from altered processing of pain in the CNS
17. OPIOID RECEPTORS
Opioids exert their action by interacting with specific
receptors present on neurons in CNS&peripheral tissue
Radiological binding studies divided the opioid receptors
into
Each has a specific pharmacological profile,pattern of
anatomic distribution in brain,spinalcord,peripheral tissues
Opioid ligands can interact with diff.opioid receptor as
agonist,partial agonist,competitive antagonist.
19. Natural alkaloids
Class of naturally occurring organic nitrogen
containing bases.
This includes compounds with neutral and
even weakly acidic properties.
Well known alkaloids include
morphine,codeine.
21. Strong analgesic
Visceral pain is relieved better than somatic pain
Degree of analgesia increase with dose
Nociceptive pain is better relieved than neuretic pain
Associated reactions are also relieved
:apprehension,fear,autonomic effects
Tolerance to pain is better
22. Mechanism of action
Two components:spinal &supraspinal
Inhibits release of excitatory transmitters from
primary afferents-at substantia gelatinosa of dorsal
horn
Exerted through interneurons-gating of pain
At supra spinal level in cortex ,midbrain&medulla -
alter processing and interpretation and send
inhibitory impulses through descending pathways
30. Methyl morphine
Converted to morphine by the body
Partial agonist at µ opioid receptor with a low ceiling effect
Available as :
Tablets:15mg,30mg,60mg
Oral solution:15mg/5ml
Injection:30mg,60mg
32. Symptoms of overdose
Bluish lips or skin
Chest pain or discomfort
Constricted,pinpoint or small pupils
Decreased awareness or responsiveness
Extreme sleepiness or unusual drowsiness
Slow or irregular heartbeat
35. It is also known as diacetyl morphine or dia morphine.
An illicit opioid synthesized from morphine that can be
a white or brown powder or a black sticky substance
The advantage of diamorphine over morphine is that
diamorphine is more fat soluble and therefore more
potent by inj.,so smaller doses of it are needed for the
same effect on pain.
Available forms: oral :5-10mg orally/IM/SC/IV repeated
every 4 hourly
Children : oral dose-0.6mg/kg/day, IV-0.01mg/kg/hr
39. It’s a drug which is an opioid cough suppressant
Helps suppress unproductive coughs and also
has a mild sedative effect but has little or no
analgesic effect.
Its average half life is about 2.3 days
Available form: oral solution: 5mg/5ml
43. Its sold under the brand name hysingla
Its an opioid used to treat severe pain of a prolonged
duration
It is also used as cough suppressant in adults
It is sold as the combination of
acetaminophen+hydrocodone /
ibuprofen+hydrocodone
Dosage :5mg/2.5mg hydrocodone/300mg or 325mg
acetaminophen
The typical dosage is 1-2 tablets taken every 4-6 hrs
as needed
47. Its sold under brand name as oxycontin
It is usually taken by mouth ,and is available in
immediate release,controlled release
formulations
Onset of pain relief typically begins within 15
mins and lasts for upto 6 hrs.
Dosage : 5mg immediate release form PO every
6 hrs.
51. Chemically unrelated to morphine
Interact with opioid receptor
Well absorbed orally,bioavailability 50%
Effects appear in 10-15 mins after oral absorption
On parenteral administration,action lasts for 2-3 hrs
Metabolized in liver-mepridinic acid and norpethidine
Excreted in urine
55. 80-100 Times more potent than morphine
Fentanyl is 500 times more lipid soluble than morphine,that’s why it is
rapidly distributed in the body because of high lipid solubility,it enters
in brain rapidly and produce peak analgesia in 5min after i.v. injection
Its elimination t1/2 =3.5 hrs
Metabolized in liver in norfentanyl(inactive)
Excreted in urine
Dose- inj in 2& 10 ml ampoules containing 50mcg per ml
56. Short acting analgesic during operative and
perioperative period
Skeletal muscle relaxant to selected high risk
patient(those undergoing open heart surgery)
Respiratory depression
Transdermal fentanyl frequently used in cancer,
terminal illness pain, chronic pain
Oral route is not used due to high first pass
metabolism
INDICATION
57. ADVERSE EFFECTS
Redness and irritation on skin wherever apply
the patch
Dizziness
Reduce cardiac contractility & HR
Constipation
59. Centrally acting analgesic
Very low action on opioid receptors
Effective both orally and i.v.(100mg=10mg morphine)
Well tolerated and low abuse potential
High oral bioavailability i.e.70-100% with repeated dosages due to
reduction of first pass effect
Metabolized in liver by demethylation
Its elimination t1/2 =4-6hr
DOSE-50-100 mg IV/IM/oral
60. INDICATION
Mild to moderate short lasting pain due to
diagnostic procedure
Pain due to Injury
Post operative pain
Chronic pain including cancer pain ( not
effective in severe pain )
61. ADVERSE EFFECT
Similar to morphine but less prominent
(vomiting , drowsiness)
Sweating
Lowering of seizure threshold(contraindicated
in epileptics)
63. Before beginning therapy,perform history
regarding allergies,use of other
medications,health history,and medical history
Caution patient not to chew or crush controlled
release preparations
Keep opioid antagonist and equipment for
assisted or controlled respiration readily
available during iv administration
64. Direct patient to lie down during IV administration
Dilute and administer IV slowly to minimize likelihood of
adverse effects
Monitor injection sites for irritation ,ex-travasation
Instruct postoperative pt.in pulmonary toilet;drug suppresses
cough reflex
Monitor bowel function and arrange for an thraquinone
laxatives for severe constipation
65. Institue safety precautions(use side rails,assist with
walking)if CNS,vision effects occur.
Provide frequent small meals if GI upset occurs
Control environment if sweating ,visual difficulties occur
Provide back rubs,positioning ,and other non drug measures
to alleviate pain.
Reassure patient about addiction liability;most patients who
receive opioids for medical reasons do not develop
dependence syndromes
66. Use caution when injecting IM or SC into
chilled areas or in patients with hypotension or
in shock,impaired perfusion may delay
absorption ;with repeated doses ;an excessive
amt.may be absorbed when circulation is
restored
Follow proper administration guidelines for IM
injections,including site rotation
67. SUMMARY
Opioids are a group of endogenous and
exogenous substances that act on receptors in
CNS & GIT.
All opioids share crucial chemical and
pharmacologic properties with morphine.
It provides effective analgesia and are used to
treat severe acute or chronic pain
