Opioids Flashcards
where do opioids come from
opium poppy seed pod juice
what 3 main drugs does opium contain
heroin, codeine, morphine
what is the difference between opiate and opioid
opiate = any natural component of opium
opioid = any natural or synthetic derivative of opium
why do we give opioids as pre-meds
because general anesthetics do not inhibit pain signal generation, so a painful stimulus during a procedure could transmit enough pain signals to the RAS to awaken the patient - giving an opioid prevents pain signal generation
where are opioid receptors present
pain pathways and in most other organ systems
T/F mammals produce endogenous opioids
T
what 5 uses are opioid drugs used for
1) analgesia
2) cough suppression (antitussive)
3) sedation
4) treatment of diarrhea
5) emesis (apomorphine)
what are the opioid receptor families that cause:
- immediate analgesia
- dysphoria
immediate analgesia:
- Mu
- Delta
- Kappa
dysphora:
- Sigma
what is the mechanism of action of opioids on pre-synaptic receptors
mu, delta, kappa receptors inhibit Ca entry, which inhibits NT release
what is the mechanism of action of opioids on post-synaptic receptors
mu receptors open K channels, which causes hyperpolarization and inhibits APs
what are the effects of mu opioid receptor stimulation (4)
- intense analgesia
- euphoria
- miosis or mydriasis
- respiratory depression (dose-dependent)
what are the effects of delta opioid receptor stimulation (4)
- analgesia
- respiratory depression, not as intense as mu
- protection from hypoxic injury
- hibernation
what are the effects of kappa opioid receptor stimulation
- moderate analgesia
- no respiratory depression
what are the effects of sigma opioid receptor stimulation
- dysphoria
- hallucinations
- respiratory and vasomotor stimulation
what can stimulate sigma receptors
opioids and some non-opioids such as ketamine
what are the 3 properties of opioid stimulation (i.e. what are the 3 ways that opioids can act on opioid receptors)
1) full agonist
2) partial agonist/antagonist
3) mixed agonist/antagonist
how does fentanyl act on opioid receptors (and which ones)
full mu agonist
how does butorphenol act on opioid receptors (and which ones)
mu partial agonist/antagonist and kappa agonist
T/F if you have a patient that presents with severe pain, you should first give a weaker opioid such as butorphanol and then give a stronger opioid such as fentanyl if pain persists
F; if you do this the butorphanol will block the effects of fentanyl by acting as a partial agonist/antagonist on the mu receptor
what two drugs are mu partial agonists/antagonists
butorphanol and buprenorphine
what is the difference between buprenorphine and butorphanol
both are mu partial agonists/antagonists, butorphanol is a kappa agonist whereas buprenorphine is a kappa antagonist
what are the 5 main analgesic opioids
1) morphine
2) hydromorphone
3) fentanyl
4) butorphanol
5) buprenorphine
what is the main anti-diarrheal opioid
loperamide
what is the main antitussive opioid
butorphanol
