half life?

Discussion in 'Pharmaceuticals' started by SpENS93, Jul 30, 2009.

  1. SpENS93

    SpENS93 Illuminati

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    can some one explain it good?
     
  2. mastercylinder

    mastercylinder Banned

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    yah the half life of the drug is the ammt of time it takes to get half of the drug out of your system about 10 half life and your considered clear--it could be 7 so i might mot be accurate on that point but im sure some one with more knowledge will point it out toyouPece fron ROCK
     
  3. SpENS93

    SpENS93 Illuminati

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    rock man ur posts are so hard to read man, use commas and peroids please dude.

    i like u no doubt cool dude but reading ur posts is a challenge.

    no offense
     
  4. Morphoxycode1

    Morphoxycode1 Member

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    Half life of a drug is the amount of time it takes for a certain dose to come down to half of the peak blood serum level. Like if you took 30mgs of oxycodone, it would reach its highest blood concentration in roughly an hour. The oral bioavailibility of oxy is relatively high, so most of that 30mgs is in your system. So, at the time when apx 15mgs is in your system, that's what's considered the half life point. After that, it fades, but it's non linear. Twice the half life doesn't necessarily equal complete clearance of a substance from your system. Hopefully, this spells it out a bit clearer!
     
  5. SpENS93

    SpENS93 Illuminati

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    so how long would it take 80mgs of oxy to be gone?
     
  6. Codmouse

    Codmouse Senior Member

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    Well, wiki will tell you a couple important things. One is the half life of said chemical (in your case, oxycodone). And the bioavailability of said chemical for which Route of Administration (ROA).

    Oxycodone half life = 3-4.5 hours
    Oxycodone bioavailability = 87% oral

    So, the half life can vary for different reasons. One of the reasons is how much you take. Another is how fast your metabolism is. Some chemicals eliminate at the same rate no matter how much you take. So, to answer your question, 80mg of oxycodone taken in one dose would have a half life of 3-4.5 hours. The life of the drug can vary substantially, so they use half life. Some drugs have a life of months for certain kinds of people.

    The higher the bioavailability is, the more of the drug gets into your system. That is why some people plug instead of use it orally. You probably know this part though.

    Your body gets rid of these chemicals through enzymes and excretion.

    Excretion is pretty straight forward, you piss, shit, sweat, breath, etc. out a certain amount of the chemical to get rid of it. Your kidneys are the main elimination tool, so you piss it out.

    Enzymes are, elementary style, little monsters that attack the chemicals to break them down. You have many different kinds of enzymes that "attack" different kinds of chemicals and at different points/places. (a good amount of human poisons are poisons because we don't have enzymes to break that chemical down).

    Take this for example;
    Psilocybin is broken down into psilocin from a enzyme essentially cutting the molecule at a certain point,
    Before
    [​IMG]
    After
    [​IMG]

    You see where the molecule was "cut"? (the gold turned to white because that is a carbon, carbon will attach to anything very quickly) Well, thats what happens to the entire molecule. Enzymes keep attacking it at different spots until its either excreted or broken down into something the body can use.

    This is where the danger of an MAOI comes in. MAO (Mono Amine Oxidase) Is an extremely important enzyme that breaks down many chemicals. Taking a MAOI (Mono Amine Oxidase Inhibitor) "inhibits" MAO from breaking down the molecule(s). Molecules that the body can not break down fast enough become poisons. So you could do a few things with this. You could potentiate a drug by taking a MAOI and make it last longer, but also inhibit the metabolism (enzyme break down and excretion) of normal things, e.g. cheese. (making cheese a poison, causing you to puke).

    Some drugs known as pro-drugs are simply a chemical that your body will turn into a normal drug, e.g. psilocybin to psilocin, heroin to morphine, etc.. This is part of the reason people get confused about heroin. Heroin is a pro-drug of morphine, but it passes the BBB (Blood Brain Barrier) faster and easier than morphine. Once it gets into your brain, it is metabolized to morphine within the brain quickly, giving a better "rush". There are enzymes in almost all liquids that come out of your body, including saliva. This is the reason why eating heroin is a waste. When its in your stomach, it is metabolized to morphine before it gets into the blood stream, essentially making you have to take a normal dose of morphine.

    But, since there is different enzymes that cut at different spots, not all heroin is metabolized to morphine. Some turns to codeine (which in turn, turns to morphine) or other non-active chemicals.

    That was major work to get all that out :/ I hope someone learns something... Maybe I should revise this a little and we should get it stickied?
     
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