The document discusses various classes of analgesics including opioids, adjuvant analgesics, and NSAIDs that are used to treat different levels of pain. It describes different opioid medications including natural and synthetic opioids, how they work on opioid receptors in the body, and their uses, benefits, risks, and nursing considerations for administration and monitoring. The goal of pain management is to effectively treat pain while minimizing risks and improving patient quality of life.

2.  Medications that relieve pain without causing
loss of consciousness “Painkillers”
 Classes of analgesics:
◦ Opioids (moderate to severe pain)
◦ adjuvant analgesic drugs.

3.  An unpleasant
sensory and
emotional
experience
associated with
actual or potential
tissue damage

4. Gate theoryGate theory

5.  Level of stimulus needed to produce the
sensation of pain
 Pain receptors: mu, kappa, and delta.

6.  Mu, kappa and delta
 Opioid drugs also react with these receptors and
thus relieve pain, so these receptors also called
OPIOID RECEPTORS.
 Each receptor family exhibits a different specificity
for the drug(s) it binds.
 The analgesic properties of the opioids are primarily
mediated by the μ receptors that modulate
responses to thermal, mechanical, and chemical
nociception.

7.  The κ receptors in the dorsal horn also contribute
to analgesia by modulating the response to
chemical and thermal nociception.

8.  Body has endogenous pain killers
◦ Enkephalins
◦ Endorphins
 The goals of pain management include
reducing and controlling pain, improving
body function and quality of life.

9.  Assist primary drugs in relieving pain, this
produce synergistic effects.
◦ NSAIDs
◦ Antidepressants
◦ Anticonvulsants
◦ Corticosteroids

10.  Very strong pain relievers
 Pain relievers that contain opium, derived from
the opium poppy or chemically related to
opium.

11. Opioid
Analgesics

12.  They can be classified according to:
◦ Their chemical structure.
◦ Their action at specific receptors.
 Of the 20 different natural alkaloids, only three are
clinically useful: morphine, codeine, and papaverine.
 Relatively simple synthetic chemical modifications of
these opium alakaloids are produced the three different
chemical classes of opioids: morphine-like drugs,
meperidine-like drugs, and methadone-like
drugs.

14.  Agonists: morphine, meperidine (pethidine),
methadone, fentanyl,codeine.
 Partial agonists: pentazocine, nalbuphine,
buprenorphine, butorphanol.
 Antagonists: naloxone, naltrexone.

15.  Main use: to alleviate moderate to severe pain.
 Opioids are also used for:
◦ Cough center suppression
◦ Treatment of diarrhea
◦ Balanced anesthesia

16.  Control postoperative and other types of pain.
 Morphine rapidly enters all body tissues, including
the fetuses of pregnant women.

18.  Short duration of action 4 hours.
 Given usually I.V OR I.M
 Orally given is absorbed buterratic and slow.
 Spasm in sphincter of oddi.
 Lead to spasm in anal sphincter---constipation.
 Cerebral vasodilatation ---increase cerebral pressure.
 Release histamine.
 Decrease the sensitivity of respiratory center to CO2.

20.  Is a weak analgesic compared to
morphine.
 It should be used only for mild to
moderate pain.
 Dextromethorphan a nonopioid cough
suppressant, is often given instead.

21.  Derivative from morphine
 Higher addiction potential.
 Higher euphoria.
 Shorter duration of action.
 Higher penetration to the CSF
 Compared to morphine.

24.  used in Anesthesia.
 Used to management Postoperative and
procedural pain.
 Rapid onset and short duration.

25.  Sufentanil , alfentanil , and remifentanil are three
synthetic opioid agonists related to fentanyl.
 They differ in potency and metabolic disposition.
 Sufentanil is even more potent than fentanyl,
whereas the other two are less potent and shorter
acting.
 These agents are mainly used for their analgesic
and sedative properties during surgical
procedures requiring anesthesia.

26.  Used as analgesic.
 Used in the controlled withdrawal of dependent
abusers from heroin and morphine.

27.  Methadone [METH-a-done] is a synthetic, orally
effective opioid that has variable equianalgesic
potency compared to that of morphine, and the
conversion between the two products is not linear.
 Methadone induces less euphoria and has a
longer duration of action.
 The actions of methadone are mediated by μ
receptors. In addition, methadone is an antagonist
of the N-methyl-d-aspartate (NMDA)

28.  Used for acute pain.
 Can be administered orally or I.M.
 Meperidine is very lipophilic and has
anticholinergic effects, resulting in an
increased incidence of delirium as
compared to other opioids.

29.  Meperidine [me-PER-i-deen] is a lower-potency synthetic opioid
 is very lipophilic and has anticholinergic effects, resulting in an increased incidence
of delirium as compared to other opioids.
 The duration of action is slightly shorter than that of morphine and other opioids.
Meperidine also has an active metabolite (normeperidine) that is renally excreted.
 Normeperidine has significant neurotoxic actions that can lead to delirium,
hyperreflexia, myoclonus, and possibly seizures.
 Due to the short duration of action and the potential for toxicity,meperidine should
only be used for short-term (≤48 hours) management of pain. Other agents are
generally preferred.
 Meperidine shouldnot be used in elderly patients or those with renal insufficiency,
hepatic insufficiency, preexisting respiratory compromise, or concomitant or recent
administration of MAOIs.
 Serotonin syndrome has also been reported in patients receiving both
meperidine and selective serotonin reuptake inhibitors (SSRIs).

30.  partial agonists used for opioid detoxification
 Mixed agonist-antagonist

31.  Contraindicated in:
 Known drug allergy
 Severe asthma
Use with extreme caution if:
 Respiratory insufficiency
 Elevated intracranial pressure
 Sleep apnea

32.  Euphoria
 CNS depression
 Nausea and vomiting
 Urinary retention
 Diaphoresis and flushing
 Constipation

33.  naloxone I.V (Narcan): half-
life is about 1 hour.
 naltrexone oral (Revia), has
longer duration of action.
 These drugs are used in the
management of both opioid
overdose and opioid
addiction( block the effect of
any future opioid dose)

34.  When treating an opioid overdose or toxicity, the
nurse must recognize the signs and symptoms of
withdrawal.
 A gradual dosage reduction after chronic opioid
use, when possible, generally helps to minimize
the risk and severity of withdrawal symptoms.

37.  Stimulation of the patient may be adequate to reverse
mild hypoventilation.
 Is this is unsuccessful, ventilator assistance using a bag
and mask or endotracheal intubation may be needed to
support respiration.
 Administration of opioid anatagonists may also
necessary to reverse severe respiratory depression.

38.  Co-administration of opioids with:
◦ Alcohol.
◦ Antihistamines.
◦ Barbiturates.
◦ Benzodiazepine.
 Can result in additive respiratory depression,
seizures, and hypotension.

39.  Mechanism of action:
 It blocks peripheral pain impulses by inhibition of
prostaglandin synthesis.
 It also lowers febrile body temperatures by acting on
hypothalamus.

41.  Mild to moderate pain
 Fever
 Alternative for those who cannot take aspirin
products
 Contraindications: known allergy, severe liver
disease and G-6-PD
 Adverse effects: is generally well tolerated.
Possible adverse effects include rash, nausea
and vomiting.

42.  Overdose, causes hepatic necrosis:
hepatotoxicity.
 Long-term ingestion of large doses also
causes nephropathy
 Recommended antidote: acetylcysteine
regimen : is more effective when given within 10
hours of overdose. It is available as IV and OP
dose.

43.  Maximum daily dose for healthy adults is 4000
mg/day
◦ 2000 mg for elderly or those with liver disease

44.  It is a centrally acting analgesic.
 Weak bond to the mu receptors and inhibit
reuptake of both norepinephrine and serotonin.
 Adverse effects are include drowsiness,
dizziness, headache, nausea, constipation and
respiratory depression.

46.  Before beginning therapy, perform a thorough
history.
 Assess for potential contraindications and drug
interactions

47.  Perform a thorough pain assessment, including
pain intensity and character, onset, location,
description, precipitating and relieving factors,
type, remedies, and other pain treatments
◦ Assessment of pain is now being considered a “fifth
vital sign”
◦ Rate pain on a 0 to 10 or similar scale

48.  Be sure to medicate patients before the pain
becomes severe so as to provide adequate
analgesia and pain control
 Pain management includes pharmacologic and
nonpharmacologic approaches; be sure to
include other interventions as indicated

49.  Patients should not take other medications or
over-the-counter preparations without checking
with their physician
 Instruct patients to notify physician for signs of
allergic reaction or adverse effects

50.  Ensure safety measures, such as keeping side
rails up, to prevent injury
 Withhold dose and contact physician if there is
a decline in the patient’s condition or if vital
signs are abnormal, especially if
respiratory rate is less than 10 to 12
breaths/min

51.  Monitor for adverse effects.
 Monitor for therapeutic effect.