Why is injection of drugs more intense then smoking?

[Rio Fantastic]

Why is it that injecting drugs is described as a more intesne experience, when smoking drugs gets to the brain quicker? I have read this about I.V heroin over smoking heroin and I.V cocaine over smoking Crack. Is it just a matter of opinion or is there a reason?

[~lostgurl~]

Because the amount you can inject in one hit can be much greater than the amount that can be smoked in one hit.

[psyche]

I'm guessing that by smoking you destroy some of the active alkaloids as well as lose them in second hand smoke.

[candy_kid]

just a thought, but maybe your lungs only absorb a certain amount per unit of time wheras you're getting 100% of the material all at once as soon as it gets to the brain through injection, albeit getting to the brain a bit slower? this could make the initial rush more intense..

[ironmics]

It's because intravenous injections bioavailability is always 100% meaning the maximum amount of drug is absorbed into your blood. Orally your body does not absorb all of the drug, same goes for all other methods of injestion.

[lulz]

Some drugs get broken down very quickly by the liver. If you eat them, they have to get processed by the liver before they enter your bloodstream.

This applies particularly to heroin and morphine. They have a high rate of "first pass metabolism", meaning a lot of the drug gets broken down the first time it passes through the liver.

If you inject it, much more of the drug can enter your brain before it gets processed by the liver. If you eat it, too much of it gets broken down before it gets into your brain.

Smoking the drug is even more effective. After entering your bloodstream via the lungs, it enters the brain only seconds later. This significantly increases the amount of the drug that affects your brain compared to other methods. But it has to be in the right form. With amphetamines and cocaine, it has to be the alkaloid form (base), not the hydrochloric acid form you usually get as a powder.

[x cynic x]

Read up on bioavailability

[madpad]

I saw some results that suggested the bioavailability of THC after smoking were around 80%.

[methMADMAN]

With swim, swim cannot smoke 1/2 gram of meth in one hit, but swim sure can slam that much.

[psyche]

I think this thread could be closed, as the reasons are already covered (and being covered again and again).