Methamphetamine reabsorption and elimination

The subject at Uni I absolutely loathe found it use today!!
Talking about factors affection drug reabsorption of various drugs........
Reabsorption of Non polar weak bases (pKa 5.0 - 12.0) exhibit pH dependant renal elimination....
As pH increases (becomes more acidic) the drugs become ionised hence less is reabsorbed and more excreted...
As pH decreases (becomes alkaline) the drug becomes more unionised therefor more likely reabsorped and less eliminated..
soo??? your probably saying?
Meth(yl)amphetamine is a non polar weak base (pKa 10) its reabsoption (via renal clearance) varies comparibly to almost nothing to almost complete reabsorption with a change in pH....
Hence acidic urine (pH 4.9 - 5.3) will cause meth to be eliminated from the body... of an 11mg dosage given, 12 hours later 6 mg was eliminated...
Alkaline urine (pH 7.8 - 8.2) will cause meth to be reabsorped... of an 11mg dosage after 12 hours .25mg was eliminated.....
I have a graph showing comparisons - but i dont know how to put it up....
So I guess this works well in 2 ways......
You wanna get more outta your Meth - alkalinise your urine - avoid acidic foods/beverages - even use an urinary alkaliser like Ural or Citravescent....
OR!!
If you scared about an upcoming drug tests - get that Urine acidic!!
[ 29 May 2002: Message edited by: RushingRococco ]

Uni giving you some useful information, well theres a first for everything
I'd imagine this is the principal most of the 'pass any drug test' kits work on, changing the acidity levels in your urine to quickly eliminate a substance or to mask its occurance. Email the graph if you'd like it shown
[ 29 May 2002: Message edited by: Fry-d- ]

Ahhh! So that's why sodium bicarbonate increases the length of a drug experience!
Thanks heaps for that RRC, very interesting ...I have no doubt I'll not remember this info, but I know where to find it if I need it
btw, anyone wanting to try this would be advised to do some research first, and as always, be careful... lengthening the effects of any drugs could also increase any detrimental effects...
There was a thread posted recently, I think it was in Health Q & A, but I can't find it, which outlined this issue... It'd be a starting point for people wanting to give it a shot...
Something mentioned which I do remember from that thread was that taking too much sodium bicarbonate could cause problems, so dosage is important... RRC or anyone else have any more info?

Here it is: Urals' make your drugs last 50% longer. To quote myself

People I can't stress this enough: if you try this, follow the dose instructions on the pack. DO NOT EXCEED THE RECOMMENDED DOSE OF SODIUM BICARBONATE. To do so may cause metabloic alkalosis, a medical emergency... Remember that neurotoxicity research has been conducted on MDMA in the absence of sodium bicarbonate. And I think it is safe to assume that the longer you are rolling, the more neurotoxic it will be. I can't endorse doing this, as it's kind of counter-harm-reduction, but I know people will try it, and feel you should know the risks involved
Taking Urals/Citravescent in normal doses isn't going to give you metabolic alkalosis, but there's always someone who'll go "mm, drugs will last longer? Think I'll have a box of Urals! wee hee!" So don't exceed the maximum daily dose people (and it is a DAILY dose - ie: spread out over the day).

Click to expand...

Elimination of MDMA is certainly slowed with alkalaemia and alkauria, however, rememeber the offset of drug effect is not so much by metabolism and elimination, but by redistribution of the drug.
What that means is that once the drug is absorbed into the blood, it goes to where most of the blood goes ! (makes sense so far).... About 75% of the cardiac output (blood flow per minute) goes to the vessel rich group - ie brain, liver, kidneys and heart. The muscle group and also the vessel poor group (fat/skin/bone etc) receive a smaller portion of the drug initially, but with time, the drug will be distributed to these organs - of note particularly is blood flow to the fat - only about 300ml/minute (of the total 5000ml/min or thereabouts). But the stores for MDMA in fat is just about endless - so over a few hours, most of the MDMA will be distributed to the fat stores away from plasma and the brain. The plasma and brain concentrations of MDMA will decrease. Given the CNS effects of MDMA related to brain concentrations, then as the drug is redistributed, the brain concentration falls and the effects subside.
Metabolism and Elimination of the drug are also occuring in this time period and relate to liver blood flow and renal blood flow.
What I am suggesting therefore
(i) Offset of activity is by redistribution more so than it is metabolism and elimination.
(ii) With alkauria (making urine alkaline) - while elimination of the drug is slower, it does not really prolong the CNS effect of the drug as much as you would expect - it does to a certain extent ... you might get another 1 or so out of your pill (at best)! [read: guessing]
Hope I haven't rained too much on your parade ?
[ 29 May 2002: Message edited by: gasbo ]

I wasnt talking about MDMA - it wouldnt work with MDMA as that is broken down into inactive compounds during metabolism.....
Methamphetamine is not metabolised - it is excreated and reabsorbed unchanged...
True it wont all get to the CNS - but an amount still will - how much im unsure - but it must be significant otherwise they wouldnt be using this test clinically - Methampethamine is only used clinically because of its CNS effects......

^ : Good discussion!
BigTrancer

RRC: feel free to email me the graph you have and I'll put it up on my webspace so you can post it...

Tarsarlan, this may have been the thread you were referring to. Babydoc and gasbo, I would appreciate it if either of you wouldn't mind adding or correcting my comments here.
web page
I've also seen this practice abused – some people swearing by a couple of Urals with an E – and I did not want to give the idea they are safe to use in slowing down weak base elimination.
Does anyone know what the safe levels of ammonium chloride are if intending to increase elimination of a base? We were given a single 500mg to slow excretion of aspirin when doing the lab prac in pharm 19001. Would that be a safe dose to take for 3 days? Or could you safely double it, and if so what additional supplements / buffers are recommended to further offset the possibility of acidosis?

My little party tip... never put on your dancing shoes without a matching roll of Mylanta antacids in your pocket. Easier to use than urinary alkalisers. Also helps settle queasy tums and neutralise stale disco breath.

Very valid and useful information, for anyone who wants to be a TIGHTARSE! If you want your peak to last longer, DUMP AGAIN. And from previous experience, being 'on the meth' for too long can cause many pshychiatric and pshycholigical problems. Under the influence of meth = no sleep, most people can go a few days without sleep but some people can be different. When i was locked up in a mental institution for a week because i was speeding for too long and lost it, you would be suprised how amny people are SERIOUSLY fucked up from being on the wizz for too long. One person could continously be on the wizz for days and be fine, but one person could be on the wizz for just over a day and end up being 'schizophrenic' for the rest of their life. Just thought i'd add my 2 cents worth.

Unfortunately 'dump again' usually = another $30-40 spent, unnecessary strain to body/brain, and increases the chance of harmful reaction or bad side-effects. My personal recommendation for getting more value from a pill is use them less frequently than monthly, and use 1/2 a pill at a time. That way you can enjoy a nice cruisy roll from the half for a couple hours, have another half later and chill, and then go home The wonderful subtle effects of MDMA can be prolonged that way, and you don't peak too hard that you can't deal with the real world. Of course some people love to peak way hard, so the half method won't do the trick, but I guess if you want to save money, then you compromise on peak intensity.
I think this post mainly refers to methamphetamine though - back to the topic?
BigTrancer

MDMA or Methamphetamine - the comments I made about redistribution still hold - offset of action is largely secondary to redistribution of the drug.