"Linear metabolization" by the body of a drug?

[Pegasus]

Ethanol is the drug I'm thinking of that fits this property. Can someone please explain what linear metabolism means?

 

[Slapdragonx]

Maybe low doses = stimulant and high doses = depressant... or vice versa.

Like nicotine.

 

[seep]

It's a term borrowed from chemical kinetics. It literally means that that the shape of its concentration vs. metabolic rate graph is a straight line has a slope of zero.

Simply put, the rate of metabolism will remain the same regardless of how much ethanol is drunk.

 

[ebola?]

This happens because alcohol saturates its main catabolic enzyme (alcohol dehydrogenase), leading alcohol to break down at a constant rate.

ebola

 

[onmyway]

however, there are two pathways for alcohol metabolism. after a lot of drinking, the microsomal metabolism kicks in, which involves p450. i dont know about the kinetics, but you will likely see two functions.

 

[ebola?]

ah...neat. How much would one need drink for this to become significantly pertinent?
And I assume that p450 wouldn't be saturated. . .

ebola

 

[onmyway]

it is neat, but i really dont know the answer. ask me in a year

i should have been more clear though, the microsomal metabolism is involved in alcohol tolerance and is implicated in some of the pathology of alcoholic liver disease. im not sure how much of a role it plays in acute intoxication (it does contribute somewhat).

 

[onmyway]

oh... i dont know about sturating p450, but we all know that booze will potentate many drugs. the metabolism at p450 is what does that , if i understand things correctly.