Posted by SLS on August 7, 2004, at 11:43:31
In reply to Re: some people just don't do well with norepinephrine, posted by linkadge on August 7, 2004, at 8:07:03
> That sounds kind of fishy to me. If a drugs is a reputake inhibitor it works at the uptake sites equally. I don't know how it could not.What sounds fishy? That drugs accumulate in tissues with varying distributions? That these various tissues (circuits) are responsible for different brain functions? That two drugs with the same pharmocodynamic properties would yield different results because they exert them in different pathways?
> I don't think there is anything wrong with using the drugs properties to predict a theraputic responce, the problem is that there are virtually no drugs for which we know all the properties :)Theoretically, of course there's nothing wrong with this concept. However, one would have to account for the myriad of biological variables that enter into an equation of a drug reaction for each drug for each individual.
1. The differential distribution into specific tissues within an individual different drugs.
2. Interindividual differential distribution into specific tissues the same drug.
These things are determined by multiple variables, some of which would include: regional vascularization and blood flow and perfusion rates, variable permeability and active transport across BB barrier, transport through anatomic different ventricles and CSF canals, distribution by varying densities of glial cells, etc. I'm just making up stuff as I go along here. :-) Again, look at the medical literature. You will see that different drugs can exert similar effects in different parts of the brain.
I can think of dozens of biological differences that can occur between any two individuals at one point in time or the same individual at any two points in time that allow for endless permutations of variables that confound the ability of one to predict the outcome of a drug trial, even if every single property of that drug were identified.
I think it is an important thing to admit to ourselves, not only our lack of understanding of the untold biological mechanisms that are incorporated into brain function, but also our lack of computational power to resolve them so as to predict output based upon input.
I'm sorry for how short and sloppily worded this is.
- Scott
poster:SLS
thread:374053
URL: http://www.dr-bob.org/babble/20040805/msgs/375062.html