Misc I don't understand how Intranasal BA can ever be lower than Oral BA?

[ChemicallyEnhanced]

I know some ARE. Like, off the top of my head Oral Morphine b/a is ~30% and Intranasal Morphine b/a is ~18%

But with snorting stuff...anything that ISN'T absorbed that way kinda just drips down into your stomach? So surely if intranasal b/a is equal to or less than oral b/a...the rest will drip down i to the stomach to match the oral b/a?

 

[TheFunkeeJunkee]

The nasal mucosa is designed for air conditioning, not drug absorption. Drugs must cross a relatively small, mucous covered surface.

If a molecule is large, polar and poorly lipid soluble, it will have reduced membrane permeability. Mucociliary clearance also further reduces absorption if the molecule in question doesn't immediately permeate nasal membranes.

All that said, nasal BA is usually higher then oral.

 

[neversickanymore]

The nasal mucosa is designed for air conditioning, not drug absorption. Drugs must cross a relatively small, mucous covered surface.

If a molecule is large, polar and poorly lipid soluble, it will have reduced membrane permeability. Mucociliary clearance also further reduces absorption if the molecule in question doesn't immediately permeate nasal membranes.

All that said, nasal BA is usually higher then oral.

i don’t think that’s true.. oral BA is often above nasal.. benzodiazepines and opiates i think.. i didn’t look it up again.. i’m thinking from previous research.. let me know if im wrong.

I think the reason people use less BA routes is the speed at which the drug hits them.. rather than the overall BA.

 

[TheFunkeeJunkee]

i don’t think that’s true.. oral BA is often above nasal.. benzodiazepines and opiates i think.. i didn’t look it up again.. i’m thinking from previous research.. let me know if im wrong.

I think the reason people use less BA routes is the speed at which the drug hits them.. rather than the overall BA.

Benzodiazepines have low nasal BA because they cannot dissolve into the mucosa, which is the medium which moves drugs into the blood stream.

As for opioids, it depends. Opioid isn't a chemical class, it's a pharmacological class. Some opioids have fantastic nasal BA, while others are poor.

But what you are touching on is mostly correct. People do not snort drugs because they are thinking about BA, they are doing it because onset of action is faster.

 

[neversickanymore]

it also is kinda complex.. when you start looking at addiction and motivation.. so people will vomit on the way to their drug supply.. before we even get the drug… what’s that all about. We have to look at the monkey and the juice.

It’s how our minds work with reward and motivation. So “ritual” and addiction starts kinda making sense when you look at the monkey and the juice. In the end the “ritual” or ROA ends up having a significant effect on people’s use. So people will use their ritual ROA not dependent on BA..

 

[ChemicallyEnhanced]

I think people are misunderstanding...I completely get HOW certain drugs can have a low-absorbtion rate via the nasal mucosa...what I am saying is...usually the vast majority of drug that is NOT absorbed by the nasal mucusa either drips down the back of the throat into the stomach or kinda stick in the nose until you snort and hack it back...in which case THAT goes down the back of the throat into the stomach...so even if only 10% is absorbed nasally, the rest will be absorbed the normal oral route...so how is it not always the same as oral at a minimum since anything NOT absorbed in the nose, is absorbed in the stomach/duodenum?

Does that make my question make more sense?

 

[neversickanymore]

makes total sense.. like the drips snorting coke. Likely they looked at levels in the blood due to nasal administration but only paid attention to the time period that would only reflect what was absorbed nasally

 

[neversickanymore]

The Pharmacokinetics of Drugs Delivered to the Upper Nasal Space - PMC

Pharmacokinetics (PK) includes how a drug is absorbed, distributed, metabolized and eliminated. The compartment providing this information is usually the plasma. This is as close to the tissue of interest that we can get, although biopsies may be ...

pmc.ncbi.nlm.nih.gov

here is article on it..

 

[ChemicallyEnhanced]

makes total sense.. like the drips snorting coke. Likely they looked at levels in the blood due to nasal administration but only paid attention to the time period that would only reflect what was absorbed nasally

Yeah, that definitely makes sense.