Part II: Opioids Flashcards
Opioid vs Opiate
Opioid acts at opioid receptors
Opiates derived from poppies
Opioid receptors are
G protein receptors
Is sigma an opioid receptor?
no
Analgesic, sedative, euphoric effects opioid receptor
mu receptors
analgesia at spinal levels opioid receptor
Delta receptors
Dysphoria opioid receptor
kappa
How would an opioid overdose kill you
respiratory depression
Miosis or Mydriasis with opioids?
Miosis from parasympathetic/cholinergic activity
Toxicity of opioids
Respiratory Depression Dysphoria Nausea and vomiting Constipation Seizures at high doses
How long does it take for opioid tolerance to develop?
2-3 weeks (tolerance reverses within same time as well)
cross tolerance means
tolerance to one opioid means tolerance to the others
Abstinence syndrome
withdrawing from opioids
Equianalgesic dose is equal to how much of morphine?
10mg
High efficacy Analgesics
Morphine Methadone Meperidine Hydromorphone Oxymorphone Fentanyl Alfentanil
why is methadone used to for opioid addiction?
it is longer acting and is used as a maintenance in opiate addicts
Low to medium efficacy
Codeine Hydrocodone Oxycodone Propoxyphene Tramadol
Partial of mixed agonist-antagonist analgesics w/ less addictive potential and less risk of respiratory depression; can be used for opioid addiction
Buprenophine used w/ naloxone (mu partial agonist used for opioid injection, suboxone is sublingual)
Butorphanol
Nalbuphine
Pentazocine
Opioids w/ primarily peripheral actions that treat diarrhea
Diphenoxylate
Loperamide
Antitussives
Codeine
Dextromethorphan (otc, not much BBB permeation)
Acute overdose is treated with
Naloxone (parenteral, intranasal), high affinity for mu receptor
Oral Opioid antagonist to prevent relapse is
Naltrexone
Opioid-induced constipation w/ poor BBB penetration
Methylnaltrexone
Naloxegol
Which opioids do not have a high 1st pass
methadone
codeine
Which opioid undergoes glucuronidation but instead of being excreted the glucuronidated form is more potent than the parent
Morphine (turns into M-6G)
Contraindications of opioid
Head injuries
Pregnancy
Impaired Pulmonary function
Hepato/renal compromised patients
Addisons or Hypothyroidism