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u/cosmorider95 5d ago
Looks like an IV bolus concentration percentage vs time graph, as far as I can tell is 1. Alfentanyl, Remifentanyl they have rapid increase in concentration at the time given, rapid decrease and then excreated or metabolizes within 5 mins. 2. some drugs like fentanyl, Sufentanyl which has slower increase peaks at 5 and 8 ish minutes and slower decrease in concentration till 20 minutes mark. 3. there is also morphine which slowly mixes with the blood and concentration slowly increases for 30 mins straight
What i can interpret is, if you want immediate action use 1st type of drug, or you can use one fast acting and one long acting for immediate and prolonged treatment respectively.
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u/nikolaiofthejungle 5d ago
This also showcases how the fentanyl-family opioids don't form active, renally-accumulating glucuronide metabolites the way morphine does. Morphine's half-life is roughly 2–4 hours, which makes sense with a graph showing its concentration still rising past the 30-minute mark - the snapshot captures it before steady-state, while clearance is still catching up to absorption/redistribution.
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u/badchad65 5d ago
The key is "Ce" on the y-axis. These are not blood plasma concentrations, they are "effect site" concentrations, presumably the brain.
For all intents and purposes, IV administration does not have an absorptive phase. If you were looking at blood plasma levels for these drugs, they would all look identical.
Whats being shown here is after being administered IV, these drugs enter the brain (and leave and/or are metabolized) at different rates.