Transcript Analgesics and Antipyretics

Chapter 10
Analgesics and
Antipyretics
Pain
When nerve signals are sent to the
brain (CNS) after feeling a hurtful
sensation inside or outside the body,
the brain perceives these signals as
pain.
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When the client complains of pain, it is
important for the nurse to treat it.
Pain: the fifth vital sign
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Pain Transmission
Tissue injury causes the release of:
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Bradykinin
Histamine
Prostaglandins
Serotonin
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These substances stimulate nerve endings,
starting the pain process.
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Pain Transmission Gate Theory
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Most common and well-described theory
of pain
Uses the analogy of a gate to describe
how impulses from injured tissues are
sensed in the brain
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Pain Transmission in the
Spinal Cord
A fibers
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Myelin sheath
Large fiber size
Conduct quickly
Sharp and welllocalized
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C fibers
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No myelin sheath
Small fiber size
Conduct slowly
Dull and
nonlocalized
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Neurotransmitters
Body has endogenous
neurotransmitters
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Endorphins
Enkephalins
Produced by body to fight pain
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Marathon runners and cyclists
Bind to opioid receptors
Inhibit transmission of pain by closing
the gate
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Management of Pain
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Treat the cause.
Select a safe analgesic.
Select the analgesic that provides
effective relief.
Provide psychological support.
Nursing actions: position change
and back rub
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Analgesics
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Analgesic drugs relieve pain without
causing loss of consciousness.
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Opioid Analgesics
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Opium has been used for thousands of
years to alleviate pain.
Opium is derived from the poppy plant.
Opium produces pain relief by attaching
to pain receptors.
Narcotics are derivatives of opium.
Narcotics are strong pain relievers.
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Classifications of Opioid
Analgesics
Classifications based on their actions:
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Agonist
Agonist-antagonist
Partial agonist
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Uses for Opioid Analgesics
Main use: to alleviate moderate to severe
pain
Opioids are also used for:
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Cough suppression
Diarrhea treatment
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Effects of Opioid Analgesics
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Euphoria
Nausea and vomiting
Respiratory depression
Urinary retention
Diaphoresis and flushing
Pupil constriction (miosis)
Constipation
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Complications of Opioid
Analgesics
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Respiratory implications
Constipation concerns
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Opioid Analgesics:
Nursing Assessments
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Perform a thorough history.
Obtain baseline vital signs and
assessments.
Assess for potential contraindications
and drug interactions.
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Opioid Analgesics:
Nursing Implications
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Oral forms–take with food
Ensure safety measures
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Opiates: Opioid Tolerance
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A common response to chronic opioid
treatment
Larger dose of opioids is required
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Opiates: Physical
Dependence
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Physiologic adaptation to the presence
of an opioid
If in need of pain relief, give the
medication
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Opiates: Psychological
Dependence (Addiction)
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A pattern of compulsive drug use when
the medication is not needed for physical
pain relief
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Opioid Analgesics:
Nursing Implications
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Law: narcotics must be kept under a
double lock
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(continued)
Opioid Analgesics:
Nursing Implications
Pain management approaches
Medical/nursing
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Medicate clients before a procedure or an
activity and/or
When they are complaining of pain
Nursing
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Back rub, musical therapy, and relaxation
therapy
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Opioid Analgesics:
Therapeutic Effects
Monitor for therapeutic effects
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Increased comfort
Activities of daily living improved
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Opiate Antagonists
Naloxone (Narcan) and naltrexone
(ReVia)
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Opiate antagonists
Bind to opiate receptors and prevent a
response
Used for reversal of opioid-induced
respiratory depression
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Opioid Analgesics:
Nursing Implications
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Rotate site for IM injections.
Follow proper guidelines for IV
administration, such as dilution and rate
of administration.
Check dosages carefully.
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(continued)
Opioid Analgesics:
Nursing Implications
Prevent constipation.
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Provide fluid and fiber.
Prevent respiratory depression.
Provide instruction for clients.
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Drug administration
Position changes
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Analgesic Agents
Analgesic agents
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Salicylates (ASA)
Acetaminophen (Tylenol)
Combination narcotic and non-narcotic
analgesics
Anti-inflammatory analgesic agents
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Nonsteroidal anti-inflammatory drugs
(NSAIDs)
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ASA (Acetylsalicylic Acid)
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Used for more than 100 years
Action: peripherally interferes with
synthesis of prostaglandins and
chemical substances released from
injured tissue
Treats mild to moderate pain
Antipyretic effect
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ASA: Side Effects
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Gastrointestinal irritation and bleeding
Increases bleeding time
Tinnitus
Children: Reye’s syndrome
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Analgesic Agents:
Acetaminophen
Mechanism of action
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Blocks pain impulses peripherally
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Relieves pain
Reduces a fever–antipyretic
Weak anti-inflammatory
Minimal effect on the central nervous system
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Acetaminophen: Side Effects
Acute overdose causes hepatic
necrosis.
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Doses of 150 mg/kg
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Long-term ingestion of large doses can result in
nephropathy
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Acetaminophen: Acute
Overdose
Treatment: acetylcysteine
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Oral form
IV form now approved
Prevents the formation of hepatotoxic
metabolites
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