Posted by undopaminergic on June 6, 2008, at 11:16:34
In reply to Ritalin (methylphenidate) vs Dextroamphetamine, posted by Molybdenum on June 5, 2008, at 19:53:49
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> I have taken Ritalin (methylphenidate) but it's not good for me. Makes me feel "speedy" and affects my judgement + I can't stand the "coming down" as it's wearing off.
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> I can get Dexedrine (Dextroamphetamine) so I really want to know from those of you who have taken both, whether Dexedrine just feels like a stronger version of Ritalin or whether it's totally different. Please tell me your experiences..!
>I haven't tried Dexedrine itself - only the milder combination of phenylethylamine (PEA) with selegiline. PEA, however, has the same mechanism of action, so my observations may be of some relevance.
Dexedrine/PEA (DXP) is much more potent than methylphenidate (MPH). The reason for this is that MPH can only potentiate the action of naturally released dopamine (DA) by blocking its reuptake, and in the absence of stimulated neurotransmitter release, MPH is without effect - fortunately, such an extreme situation does not occur in practice. DXP, on the other hand, empties neuronal storage vesicles of their DA content and reverses the direction of the DA transporter, so that it transports large quantities of DA into the synapse - since this occurs in the absence of neuronal firing, DXP causes the release of neurotransmitters that would not have been released if it were not for the drug.
Greater potency of DXP, may mean greater speediness and a more potent effect on judgement. On the other hand, if you're lucky(?), massive synaptic concentrations of DA may cause aninhibition of neuronal firing - probably by enhanced stimulation of presynaptic autoreceptors - and this may be experienced as a paradoxical calming or relaxing effect. This may not last, perhaps due to the desensitation of autoreceptors, and so speediness may follow after an initial period of calming effects. It may be possible to restore the calming effect by increasing the dose. Unfortunately, some areas of the brain - such as the prefrontal cortex - are sensitive to excessive levels of neurotransmitters, so larger doses of DXP may result in executive dysfunction and impairment of working memory. These are some of the mechanisms and factors that may play a role in your success with DXP.
You may find the "coming down" from MPH unpleasant, but wait till you see that of DXP, and all your adverse experiences with MPH will seem exceedingly benign. Remember the storage vesicles that were emptied by DXP? They have to be refilled, and during the time it takes for that process to complete, you will essentially be dopaminergically deficient. To add insult to injury, this refractory period of neurotransmitter replenishment is in addition to the downregulation of receptor density or sensitivity that also occurs with MPH, but that is much more severe with DXP due to its greater potency.
You will become totally dependent on the drug, as you will be anergic and quite possibly dysphoric and anhedonic without it, forcing you to take the drug just to restore the previous baseline of function that you enjoyed prior to starting it. Another plausible development is that of experiencing increasingly intense craving for the drug during any attempts at abstience, so that you become hopelessly entangled in a web of addiction.
If, for some remarkable reason, you do not experience significant tolerance, you may be able to use DXP successfully. Otherwise, however, prolonged use of DXP is unsustainable, or at least unproductive - at least in the absense of coadministration of agents that prevent tolerance - such as possibly memantine or dextromethorphan.
Good luck!
(By the way, I really did exaggerate matters a bit, so you may perhaps not need quite as much luck as it might seem based on the above. ;)
> I know there's a promising new group of stimulants being developed called Ampakines, some of which are (Piracetam, Aniracetam, Oxiracetam, Pramiracetam, Phenylpiracetam = Carphedon = Phenotropil).
>Although at least some of the racetams have AMPA-modulatory actions, they are usually referred to as nootropics rather than ampakines, while the latter term is applied to the more potent and specific AMPA-modulating drugs, such as the CX-series of compounds, including the one you mention below:
> The VERY new ones sound better again but as far as I can tell they are unavailable, ie CX717.
>
poster:undopaminergic
thread:833197
URL: http://www.dr-bob.org/babble/20080606/msgs/833288.html