Posted by Dave001 on August 31, 2004, at 10:29:18
In reply to Re: Ecstasy safely converted and prescribed? » Dave001, posted by Larry Hoover on August 31, 2004, at 9:19:46
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> > ---- begin quote ----
> > > The first abstract below demonstrates this relationship nicely. Note that the threshold for brain damage, or even abnormal brain chemistry post-use, is greater than 4 mg/kg (by interperitoneal injection, not oral), a dose three times the typical human dose, employing a route of intake not normally employed by humans. Only
> > ----- end quote -----
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> > The study you're quoting involves rats. You can't directly compare animal doses to human doses without first calculating the human equivalent dose (HED) which takes into account such things as body surface area. To get the HED for rats you should multiply the dose above by 0.16. So 4 mg/kg * 0.16 = 0.64 mg/kg. That's a total dose of only 38.4 mg in your 60 kg human. Repeated dosing of MDMA and amphetamines gets even more complicated because rats metabolize the drug so much faster than humans.
> >
> > Dave
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> > <snip>
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> I appreciate the digression into uncertainties of estimate. There are always assumptions made in cross-species comparisons, of course. There areAnd thus the need to correct false assumptions, such as a 1:1 association with human metabolic rate. ;-)
> also different ways to estimate HED (I assume yours is BW to the 2/3 power, rather than the metabolic parameter BW to the 3/4). Primate
It is generally preferable to use standardized conversion factors which have demonstrated reasonable accuracy. Using generic formulas is usually is only advisable if the species is not listed or if the weight falls outside of the specified ranges. These are the methods used by drug companies when extrapolating from animal data to determine initial human doses.
> studies are probably more applicable, and the same pattern is found as in the rats. I.e. only extremely high doses, or recurrent use without sufficient recovery time, lead to measurable neuronal damage or changes in neurotransmitter concentrations. Another variable to consider is antioxidant status, and I wonder if e.g. ravers aren't a little more likely to eat poorly?
>Quite possibly. I would imagine the body naturally kicks the production of antioxidant enzymes such as superoxide dismutase, glutathione peroxidase, and catalase, etc., into full gear in the presence of such toxins.
> By no means was I suggesting the referenced article was conclusive, but merely suggestive. There is a toxic threshold, and the issue of exceeding that threshold is not clearly defined in humans.
My comments were not intended to make any inference regarding the toxicity of MDMA.
Dave
poster:Dave001
thread:383476
URL: http://www.dr-bob.org/babble/20040830/msgs/384680.html