Question

Why are so many anesthesias such as ether and chloroform fat soluble?

Answer 1

The lipid bilayer is a thin polar membrane made up of two layers of lipid molecules, these lipid bilayer surrounds every cell membrane, so anasthetic agents like chloroform and ether being fat soluble readily dissolves in these lipid bi layer, greater lipid solublity enhances diffusion through nerve sheath towards the neural membrane, thus lipid solublity corelates with drug potency or in short we could say that greater the lipid solublity the easier is for these anasthetic agents to traverse the lipid bi layer of the neuronal cell membrane, therby affecting the potency.

Fat solublity or liphophilicity determines the onset and duration of anasthetics, the more fat soluble it is, the longer the onset time and longer the duration, this is because fat soluble anasthetics are better absorbed into fat (they dont produce any physiological effect in fat), this fat serves as reservoir for the drug which then equibrate with the rest of the body after the anasthetics is discontinued preventing the concentration of these agents in the brain from decreasing as quickly as it otherwise would.The amount of anasthetics remaining in the body is greater with anasthetics that are fat soluble because of which their duration is longer.