IV Opiates (Stanford) Flashcards
Main Opioid mech of action of inducing analagesia and where are the receptors mainly located
Mu opioid receptor agonism
located:
brain
spinal cord
Side effect profile of opioids
(start with dangerous to common)
Respiratory Depression
Bradycardia
Hypotension
Sedation
Chest wall rigidity
Miosis (pinpoint pupils)
Common Post-op/Inpatient concerns:
Pruritus
Constipation (Ileus!)
Urinary retention
Nausea
What are the types of opioid receptors and what do they do? (need to update)
Mu:
- supraspinal analgesia (Mu1)
- respiratory depression (Mu2)
- physical dependence
- muscle rigidity
Kappa:
- analgesia without respiratory compromise
- sedation
- spinal analgesia
Delta:
- analgesia
- behavioral
- epileptogenic
What are approx analgesic equivalences of the following drugs compared to Morphine 5mg IV for single bolus?
Fentanyl
Remifentanil
Hydromorphone
Methadone
Meperidine
Alfentanil
Sufentanil
Equivalent to 5mg of morphine:
Fentanyl - 50mcg (100x potent)
Remifentanil - 50mcg (same)
Hydromorphone - 0.75mg (~5-6x more potent)
Methadone - 2.5mg (2x potent)
Meperidine 37.5mg (weaker analgesic)
Alfentanil 150-250mcg
Sufentanil - 5mcg (1,000x potent, Superfentanil!)
What are approx analgesic equivalences of the following drugs compared to Morphine 5mg IV for single bolus?
Fentanyl
Remifentanil
Hydromorphone
Methadone
Meperidine
Sufentanil
Equivalent to 5mg of morphine:
Fentanyl - 50mcg (100x potent)
Remifentanil - 50mcg (same)
Hydromorphone - 0.75mg (~5-6x more potent)
Methadone - 2.5mg (2x potent)
Meperidine 37.5mg (weaker analgesic)
Sufentanil - 5mcg (1,000x potent, Superfentanil!)
Peak onset time and duration of action:
Morphine
Fentanyl
Remifentanil
Hydromorphone
Methadone
Meperidine
Alfentanil
Sufentanil
*Morphine 10-20min, 4hr
*Fentanyl 3-5min, 30min-1hr
*Remifentanil 3-5min, 10min
*Hydromorphone 10-15min, 2-4hr
*Methadone 10min, 24hr
Meperidine 10-15min, 2-4hr
Alfentanil 1-2min, 5-10min
Sufentanil 3-5min, 30min
Peak onset time and duration of action:
Morphine
Fentanyl
Remifentanil
Hydromorphone
Methadone
Meperidine
Alfentanil
Sufentanil
*Morphine 10-20min, 4hr
*Fentanyl 3-5min, 30min-1hr
*Remifentanil 3-5min, 10min
*Hydromorphone 10-15min, 2-4hr
*Methadone 10min, 24hr
Meperidine 10-15min, 2-4hr
Alfentanil 1-2min, 5-10min
Sufentanil 3-5min, 30min
Intraoperative and post-op side effects associated with remifentanil infusion.
How is it metabolized?
- Bradycardia is common during infusion
- Acute opioid tolerance can develop from sudden cessation of infusion vs titrate down
- Opioid induced hyperalgesia is associated with longer infusions with higher infusion doses (>0.15mcg/kg/min)
- Plasma esterases
Describe the metabolite of morphine and how it is eliminated
metabolite is morphine-6-glucuronide which has analgesic effects and is renally excreted (clinically relevant if patient has ESRD or renal failure)
What are the mechanisms of the two racemic forms of methadone?
L Methadone = opioid agonist
D Methadone = NMDA antagonist
What is meperidine (Demerol) commonly indicated for?
Describe its metabolite, elimination and relevant side effects
What is its infamous drug interaction ?
Post-op shivering, has some analgesic effects
toxic metabolite is norperidine which lowers seizure threshold and is renally secreted (watch out for meperidine causing seizures in ESRD patients)
It has anticholinergic effect that can result in tachycardia, it can cause histamine release, and has a euphoric effect with less respiratory compromise
Libby Zion Law: 80hr max, due to Meperidine interaction with MAOi that resulted in serotonin syndrome in 18yo.
mechanism of buprenorphine
mechanism of meperidine
mechanism morphine
partial mu agonist and kappa antagonist
mu agonist and Ach antagonist
mu, kappa, delta agnosits
mechanism of butorphanol spray
mechanism of nalbuphine injection
mixed mu agonism and antagonism with kappa agonism
partial mu ANTAGONIST and kappa agonist
