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Y.MD 01-21-2011 02:51 PM

Inhaled Anesthetics
i need help with inhaled anesthetic topics, blood/gas partition coefficient. I don't understand why more soluble anesthetic has slow onset of action. i am really confused. :toosad:

dr z 01-21-2011 03:04 PM

More soluble , easy diffusion cross lipid memb
the more soluble the gas the more it diffuses back and forth in blood and lipid tissues CNS so it takes longer to achieve INDUCTION (high potency)

drugs with increase solubility in lipids = increase potency = inverse MAC like HALOTHANE :)

Y.MD 01-22-2011 06:52 AM

but why has low onset of action? it has not logic for me.
this is the only topic that make me crazyyyyyyy:toosad:

dr z 01-22-2011 07:21 AM

redistribution of lipid soluble drugs
to achieve a therapeutic effect u have to get a suitable amount/concentration of drug in blood or the targeted tissue ( CNS here)

so whan the drug is so diffusable then it would require a very high plasma concn to achieve an effective CNS conc and haothane family ossilates between the two compartment so it is hard to achieve onset of action fast.
hope this helps :)

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