Alrighty, here goes. Try to keep up, because I'm going to do this fast.
First, Naloxone vs Bupe -
The problem is that you are thinking that naloxone reverses the effects of opiods, when really you need to know that naloxone is actually an opiod. Think of your opiod receptors as being able to be in 1 of 3 positions. Either ON (agonist), Neutral (no drugs), or OFF (antagonist). Buprenorphine is technically a partial agonist, but for purposes of this, assume it' an agonist, and naloxone is an antagonist.
All opiods want to bind to your receptors, but only 1 can bind at a time. To determine which one gets to stay binded depends on a drugs affinity. Bupe has a stronger affinity than naloxone, so bupe will bind, putting your receptors in an ON position. The naloxone cannot bind. So while they may be working against each other, they are both opiods, and the stronger affinity always wins. You cannot use naloxone to treat a buprenorphine overdose. However, naloxone can be used to treat a heroin overdose because it's stronger than heroin, so it will kick heroin off the receptor and switch it to the OFF position (which will allow your CNS to function again temporarily)
Second - Why naloxone is pointless
Pretty much, naloxone is only in suboxone for show. There is no good reason for it. People like to say stupid rumors how you cant shoot up because of the naloxone, or whatever - WRONG.
As stated before, bupe will not let naloxone bind, and it has a short elimination half life, and will just go away pretty quickly. It doesn't matter how you take it, sublingually or inject it, the naloxone will NEVER be able to bind. People would say that it's not absorbed when taken normally, but when you shoot it you'll get sick - WRONG.
Pretty much, it's in there for show, and does NOTHING!
Why you get precipitated withdrawals.'
This one is slightly more tricky, because it depends on the person, their tolerance, amount they take of bupe vs other drug.
I'll try to make this simple.
- In order for your body to not be sick, lets say you need 100 Dope Units (DU).
- Your body has 10 opiod receptors, which can each hold 1 opiod (remember, stronger affinity wins).
- You take 10 receptors worth of heroin, which has a DU of 10. So 10 x 10 = 100 DU.
- You will NOT be sick, because your body has the 100 DU you need.
- Now lets say on top of that you take 10 receptors worth of bupe. (Bupe has a stonger affinity than heroin, so it will kick heroin off) but bupe only has a DU of 5. So 10 x 5 = 50.
- Your body now has 50 DU, not 100. This will make you sick.
Pretty much, since bupe has more affinty, but less DU, you'll get sick. However, if you're already sick and are at 0, then taking 50 of bupe will make you less sick. Eventually your body will get used to not being sick with 50 DU, and you'll be fine. (Obviously theres more based upon dose, etc, etc, but I think the general idea should suffice?)
If other opiates were weaker than heroin with stronger affinity the same thing could happen.
Hopefully that made some sense.
