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L-amphetamine and l-methamphetamine

S

smartshop

Bluelighter
Joined
Dec 21, 2003
Messages
184
I was wondering what the effects of the l-forms of these drugs do in respect to neurotransmittersystems in comparison to their d- counterparts. I like to use deprenyl once in a while and have not been able to find much on the metabolites, l-amphetamine and l-methamphetamine, on pubmed or psychlit (the onlly databases i have access to). Does anyone have access to more chemical oriented databases where this information might be available?
...dl-deprenyl should be interesting too!!......20 mg per day as a non- neurotoxic/fast acting / anti-depressant?! hmmm...
 
The L form of PEA derivatives is usually alot weaker than the corresponding D form. It is in fact almost inactive on its own. Although the D form is stronger than a racemic mixture, the L isomer is thought to alleviate some of the jitteryness of the pure D isomer. This is according to uncle fester and what i have read in pihkal.
 
It alleviates jitters? I thought it increased peripheral effects, heart rate/apetite loss/etc, without adding much to the mental effects/euphoria. I also thought they put it in Adderall to limit somewhat the abusability...

But I have no references, this was just something I took for granted...
 
Yes, just to recap - the d-form is far more potent than the s-form. The s-form is essentially inactive. Hence the d-form is roughly twice as potent as the racemic 'natural' form. But uncle fester (the expert) actually prefers racemic methamphetamine to the pure d-isomer because he (and I believe Dr Shulgin) regard the intoxication of the racemic version as being smoother.
 
I wouldn't go so far as to say, far more potent... the dopamine and noradrenaline release EC50s are about a factor of 2 different... though their serotonin releasing values are a bit more substantially different, about a factor of 7 out.

I wonder if there's a pharmacokinetic difference...
 
The L-isomer is ephedrine. The D isomer is methamphetamine. That's the difference.
Click to expand...


That's not true at all. You are probably kidding, but let's just try to clean up the stereochemical confusion in this thread:

(S)-amphetamine: releases NA and, at higher concentrations, DA from presynaptic neuron via 'reverse transport.' Also called dextroamphetamine.

(R)-amphetamine: less effective release of NA, virtually inactive at DA neurons. Also possesses mild activity at post-synaptic alpha adrenergic receptors (uM affinity). Perhaps also levoamphetamine does not pass through the blood-brain barrier as effectively as dextroamphetamine, hence stays in the PNS? That, however, is just a theory.

(S)-N-methylamphetamine: potent releaser of DA, but also possesses 5-HT- and NA-mediated effects at high doses. Powerful and neurotoxic psychostimulant. 'Nuff Said.

(R)-N-methylamphetamine: 1/100 as effective a central stimulant as its enantiomer. Levomethamphetamine has efficacy as a NA-releasing agent and also possesses affinity at alpha and beta-1 adrenoreceptors.

Ephedrine is not (l)-methamphetamine, it is alpha-hydroxy-methamphetamine and has mainly peripheral adrenergic effects.
 
Can't remember ref

I wonder if there's a pharmacokinetic difference...

Don't know if there is for amphetamine isomers, buth there is a difference in the rate of N-dealkylation of the different optical isomers of N-ethylamphetamine.

I remember seeing that mentioned in Chemical Abstracts somewhere, but that's no help in pinpointing where I found it due to the no of short articles CA contains (bleedin' millions!)


PS. To add a bit to Riemann Zeta's post. The confiuration of the methyl group, methylamino group, hydrogen and benzylic (hydroxybenzilic in case of ephedrine) about the beta carbon atom is the same for l-ephedrine and d-methamphetamine (it's why l-ephedrine is preferred for meth synth over racaemic ephedrine - the end product is purely the d-methamphetamine isomer)
 
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I HATE D,L, R,S !FUCK! :X

Fucking non-IUPAC Americans. *sigh*

Got any refs for some of those g-protein coupled receptor affinity claims Riemann Zeta?
 
Riemann Zeta said:

(S)-N-methylamphetamine: potent releaser of DA, but also possesses 5-HT- and NA-mediated effects at high doses. Powerful and neurotoxic psychostimulant. 'Nuff Said.

(R)-N-methylamphetamine: 1/100 as effective a central stimulant as its enantiomer. Levomethamphetamine has efficacy as a NA-releasing agent and also possesses affinity at alpha and beta-1 adrenoreceptors.

Ephedrine is not (l)-methamphetamine, it is alpha-hydroxy-methamphetamine and has mainly peripheral adrenergic effects.
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Thank you for clearing that up. My ignorance exists no longer.
 
ok. so it seems the l-forms have more of an NA effect, and no Da or 5-HT effects. And of course lesser overall potency. Any references?
 
The L form of methamphetamine I believe is used to be employed in OTC Vicks inhalers or something to that effect. We know that it does not have DAT activity because it is not self administered. We know it has NET activity because it is a brochodilator, cf. salbutamol. We know it does not exhibit SERT activity.
 
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okay...so a question here.
why do you think many people would feel that racemic amphetamine (be it benzedrine or the preparation of salts in adderall) or even racemic methamp is "smoother" than the respective d-isomers?

Can this be explained by the different isomers having different time courses in terms of blood-concentration, or what?

ebola
 
I dunno. Go and ask the aliens.
 
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smartshop said:
ok. so it seems the l-forms have more of an NA effect, and no Da or 5-HT effects. And of course lesser overall potency. Any references?
Click to expand...

L-meth is about half as potent at DA and NA release, and about 6 times less potent at 5-HT release...

...That is of course, on a single cell level... Quantifying these things at whole animal level gets tricky.
 
>>I dunno. Go and ask the aliens.>>

I think I'd have to use the said racemic meth for 5 days for this to work. :)

ebola
 
l-meth is still available OTC in the vick's vapor inhalers. Great way to win a $100 bet (that you can buy methamphetamine at Target without breaking any law or without any prescription). They call it levmetamphetamine on the label.
 
ebola! said:
okay...so a question here.
why do you think many people would feel that racemic amphetamine (be it benzedrine or the preparation of salts in adderall) or even racemic methamp is "smoother" than the respective d-isomers?

Can this be explained by the different isomers having different time courses in terms of blood-concentration, or what?

ebola
Click to expand...

This topic is odd. Everyone on Other Drugs/Drug Basics says Dexedrine is FAR better than Adderall.
 
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