Please confirm topic selection

Are you sure you want to trigger topic in your Anconeus AI algorithm?

Please confirm action

You are done for today with this topic.

Would you like to start learning session with this topic items scheduled for future?

Updated: Aug 12 2022


  • Snapshot
    • A 22-year-old male is brought into the emergency department by the police due to depressed mental status. He was found in the park with an empty syringe by his side. Vital signs are notable for a respiratory rate of 7 breaths/min. Physical exam is significant for bilateral track marks, and miotic pupils.
  • Introduction
    • Opioids act on mu (most important), kappa, and delta transmembrane receptors in the central and peripheral nervous system
      • mu, kappa, and delta receptors are Gi protein coupled
        • inhibition of adenylyl cyclase → decrease cAMP concentration → increased K+ conductance + decreased Ca2+ conductance
          • inhibits presynaptic neurotransmitter release
            • prevents release of acetylcholine, norepinephrine, serotonin, glutamate, substance P
          • inhibits postsynaptic depolarization
    • Endorphines, enkephalins, dynorphins are examples of endogenous opioid peptides
    • Pharmacokinetics
      • morphine, hydromorphone, oxymorphone undergo first pass metabolism
        • morphine gets metabolized to morphine-6-glucoronide, which is highly active (the active analgesic)
      • opioids are generally metabolized by liver into inactive glucuronide conjugates
        • after metabolism they get excreted by the kidneys
      • codeine, oxycodone, hydrocodone are metabolized by hepatic cytochrome enzymes
        • cytochrome has genetic variability → variable analgesic response
      • meperidine can get metabolized to normeperidine N-demethylation
        • normeperidine can lead to anxiety, tremors, seizures
      • heroin gets metabolized into 6-monoacetylmorphine, which can be detected on urine screening
  • Clinical Uses
    • Physicans should assess patient's pain medication history prior to prescribing opioids
      • Drug Classification
      • Subclass
      • Medication
      • Agonists
      • Morphine, fentanyl, meperidine, codeine
        • pain management
      • Methadone
        • detoxification and maintenance (agonist) treatment of opioid addiction
        • pain management
        • has relatively slow onset of action (30 minutes) and long half life (1 day)
      • Mixed agonist-antagonist
      • Buprenorphine
        • maintenance treatment of opioid addiction
        • pain management
        • withdrawal symptoms
        • can induce withdrawal symptoms
      • Antagonists
      • Naltrexone
        • treatment of alcohol dependence
        • prevention of opioid relapse
          • blocks the effects of opioid if used
      • Methylnaltrexone
        • opioid-induced constipation
      • Naloxone
        • opioid overdose
          • for reversal of opioid depression
      • Antitussives
      • Dextromethorphan
      • Codeine
      • Others
      • Tramadol
        • pain management
      • Butorphanol
        • pain management
      • Loperamide/dyphenoxylate
        • manages diarrhea
  • Side Effects by System
      • Opiate Pharmacologic Effects by System
      • System
      • Side Effect
      • Central nervous
      • Analgesia
      • Euphoria/dysphoria
      • Miosis
        • tolerance does not develop in miosis
      • Sedation
      • Cough reflex inhibition
      • Cardiovascular
      • Vasodilation
      • Hypotension
      • Pulmonary
      • Respiratory depression
      • Gastrointestinal
      • Constipation
        • tolerance does not develop to constipation
      • Increased tone/pressure in the biliary sphincter
      • Nausea and vomiting
      • Genitourinary
      • Urinary retention
      • May prolong labor
      • Endocrine
      • Increases antidiuretic hormone (ADH) and prolactin secretion
      • Decrease luteinizing hormone (LH) secretion
      • Dermatological
      • Pruritus
      • Flushing
  • Toxicity
    • Acute overdose triad
      • miosis, respiratory depression, coma
        • respiratory depression due to ↓ response to ↑ pCO2
    • Tolerance
      • a decrease in pharmacologic effect after prolonged drug usage
        • secondary to down-regulation of opioid receptors
      • miosis and constipation are not affected by tolerance
      • NMDA receptor antagonists (eg, ketamine) and delta-receptor antagonists have been reported to prevent opioid tolerance
    • Withdrawal side effects
      • pain originating from the CNS
      • flu-like symptoms
        • lacrimation, sweating, rhinorrhea, salivation
        • muscle cramps and spasms
      • yawning
      • diarrhea
    • Drug specific side-effects
      • meperidine (seizures and serotonin syndrome with MAOIs/SSRIs)
        • only opioid to cause mydriasis vs miosis (pinpoint pupils)
      • nalbuphine (hallucinations)
  • Contraindications
    • Head trauma
      • ↑ pCO2 can cause vasodilation and ↑ intracranial pressure
    • Pulmonary dysfunction
      • patient may not be able to compensate for respiratory depression
    • Liver/kidney dysfunction
      • poor excretion mechanisms may result in accumulation
    • Adrenal/thyroid deficiencies
      • opiates may show greater effects
    • Pregnancy
      • fetus may show dependency
      • exception is meperidine
1 of 0
1 of 8
Private Note

Attach Treatment Poll
Treatment poll is required to gain more useful feedback from members.
Please enter Question Text
Please enter at least 2 unique options
Please enter at least 2 unique options
Please enter at least 2 unique options