Prodigy- Opioid and Non-opioid analgesics Flashcards
What is responsible for the initial rapid drop in plasma concentration after an IV bolus of Fentanyl?
What about the second, slower decrease in plasma concentration?
the rapid distribution into the highly perfused organs (VRG)
The second, slower decrease in plasma concentration occurs as the drug distributes into the less well-perfused tissues such as muscles and apidose tissue
What is the termination of analgeisa due to in opioids with a high Vd vs low Vd
high vd is due to redistribution of the drug away from its site of action
low vd drugs termination is due to clearance of the drug
T/F: all 3 opioid receptor types can produce both supraspinal and spinal analgesia
True
What is the mechanism by which the kappa receptor produces diuresis?
From Vasopressin inhibition
Opioids produce an excitatory effect on what that results in miosis?
excitatory effect on the Edinger-Westphal nucleus of the oculomotor nerve produces miosis
Even when the PaCO2 is controlled, ________ & __________ (2 drugs) are both associated with mild increases in the ICP of ____ - ____ mmHg
Fentanyl & Sufentanil
6-9mmHg
Mechanism by which Morphine can cause bradycardia?
due to increased vagal activity
What does it mean when the CO2 response curve shifts to the right?
It means a higher level of CO2 than normal is required to stimulate ventilation
Morphine has been shown to (increase/decrease) the tone of the detrusor muslce of the bladder and (increase/decrease) the urinary sphincter muscle
Increase both
-increased sense of urgency and inability to urinate
What is the only opioid that is entirely unaffected by hepatic disease?
Remi
(metabolized by plasma esterases)
Where is the sphincter of Oddi located?
Where the CBD and pancreatic duct meet to empty into the duodenum.
Which opioid is less likely to cause spasm of the sphincter of Oddi compared to the others?
Meperidine
What is the most common side effect of neuraxial opioids?
which population is affected the most?
Pruritus (itching)
-Obstetric patients prob from the combined pruritic effect of estrogen
What drug has been shown to be more effective than Benadryl, propofol, and naloxone in treating pruritus from neuraxial opioids and does not reverse analgesia?
Nalbuphine
Hyperventilation and alkalosis will (increase/decrease) the non-ionized fraction of morphine
increase (will enhance the activity of morphine)
T/F- patients taking MAOIs may exhibit an exaggerated response to morphine
True
-MAOIs can impair the conjugation of drugs with glucuronide.
What populations exhibit prolonged clearance times with morphine? (2)
Elderly and neonates (within first 4 days of life)
Is the potency of morphine noted to be greater in men or women?
Women
T/F codeine is a derivative of morphine
True
What’s the significant advantage of alfent over fent and sufent?
Rapid onset due to it’s low PKA resulting in 90% of the drug existing in the non-ionized form at physiologic pH
For alfentanil, what is the time to equilibrate at the site of action?
1.4 minutes
Which opioid should be used in caution with parkinsons patients and why?
Alfentanil bc it can result in acute dystonic reactions from disruption of central dopaminergic transmission by alfentanil.
Major metabolite of fentanyl
Norfentanyl (inactive)
What characteristic of Sufentanil accounts for the increase in Vd and elimination half time in obese patients?
High lipid solubility
What does sufentanil bind significantly to?
What population would this affect?
Alpha-1-acid glycoprotein
Neonates (have decreased levels of AAG and would require lower doses bc there will be increased free fraction of the drug)
Sufentanil has a (high/low) hepatic extraction rate. what’s the significance?
High ER - metabolism is more sensitive to changes in hepatic blood flow than to changes in the enzymatic ability of the liver to metabolize it.
What opioid can’t be given epidurally or intrathecally and why?
Remi
- it’s prepared with glycine which can cause neurotoxicity by means of skeletal muscle weakness
During hypothermic coronary artery bypass, the clearance of remifentanil (increases/decreases) by ____% and why
decreases 20%
- reflects the hypothermic effects on the activity of esterases in the blood and tissues
How does tramadol work?
It’s an opioid that acts centrally on mu, kappa, and delta receptors to produce analgesia.
It also inhibits the reuptake of NE & serotonin.
Why isn’t tramadol routinely used in the peri-op period?
High incidence of N/V
Who should tramadol be avoided in?
Pts with a hx of epilepsy - can increase the risk of seizures.
an IM dose of Buprenorphine has an onset of ____ and duration of _____
onset 30 minutes
duration 8 hours
T/F- respiratory depression from buprenorphine can be difficult to reverse with naloxone
True