What SE do the opiates typically have on the CV system?
What effect do morphine and meperidine have on the CV system?
-They both cause histamine release which causes hypotension and decreased SVR
-Meperidine is structurally related to atropine so it can cause an increased HR
What effect can fentanyl have on the CV system?
At high doses it can cause vagus mediated bradycardia
What SE do the opiates typically have on the respiratory system?
-RR depression (more than decrease in TV)
-Decreased response to CO2, decreased hypoxic drive, chest wall rigidity
Is the chest wall rigidity only limited to the chest?
-No, it can affect all striated muscle.
-Can possibly prevent ventilation
-Can affect larynx and pharynx
Chest wall rigidity is most associated with what opioids?
Highly lipid soluble opioids like fentanyl
What SE do the opiates typically have on the CNS?
-Decreased CBF, ICP, CMRO2 but less than the benzos or barbs
-Stimulates the chemoreceptor trigger zone (N/V)
What SE do the opiates typically have on the GI system?
Increased gastric emptying time, decreased peristalsis, biliary spasm
What SE do the opiates typically have on the endocrine system?
Block stress hormone response more than the volatiles. Blocks catecholamines, cortisol, and ADH.
Which opioid has the least effect on the common bile duct pressure and might be desirable in a chole with bile duct exploration?
Demerol; all the opioids increase common bile duct pressure and hence delay gallbladder emptying, but demerol does this to a lesser degree. Opioids should be avoided, but if you had to give one, give demerol.
What opioid is the prototype and standard?
What type of pain is morphine best for?
continuous dull pain, best given preemptively
Why does morphine take 15-30 mins to peak, with only 0.1% reaching the CNS at peak plasma concentrations?
Morphine is poorly lipid soluble and has a high degree of ionization.
Other than analgesia, what's another use of morphine
Pulmonary edema as it decreases the sensation of SOB
What are major SE of morphine? (think respiratory, immune, and cardiac)
-venous pooling, decreased CO, orthostatic hypotension, possible bradycardia
What's the peak of morphine?
What's the onset of morphine?
< 1 min
What's the duration of morphine?
What's the normal range of analgesic IV doses for morphine?
List the elimination half time of the following agents from shortest to longest: morphine, meperidine, fent, alfent, sufent, remifent
remi, alfent, morphine, sufent, meperidine, fent
What structural classification is meperidine derived from?
phenylpiperidine (fentanyl family)
What drug (non opioid) is meperidine structurally similar to?
Atropine, hence can cause increases in HR
10 mg morphine = ____ mg meperidine?
What effect does meperidine have on the heart that is unique to the opioids?
decreases myocardial contractility
What's the only opioid that causes an increase in HR?
meperidine, all the other opioids decrease HR
Which 2 opioids have the greatest effect on MAP?
remifent and alfent
Do the opioids cause bronchodilation?
No. Morphine and meperidine cause histamine release which would cause bronchoconstriction.
Best use for meperidine? What receptor?
Post-op shivering. Kappa receptors.
What drug class should be avoided with meperidine? Why?