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Dr. Bob is Robert Hsiung, MD,
[email protected]Shown: posts 1 to 20 of 20. This is the beginning of the thread.
Posted by 1980Monroe on July 23, 2004, at 8:36:20
I seen so many posts ask this but i never read the awnsers, i know that adderall has the I-isomer mixed 25% with the D form.
But does adderall have slower onset? or faster?
Just general info thanks.
Posted by linkadge on July 23, 2004, at 8:46:46
In reply to whats the diff. between adderall and dexedrine, posted by 1980Monroe on July 23, 2004, at 8:36:20
Posted by chemist on July 23, 2004, at 9:05:25
In reply to whats the diff. between adderall and dexedrine, posted by 1980Monroe on July 23, 2004, at 8:36:20
> I seen so many posts ask this but i never read the awnsers, i know that adderall has the I-isomer mixed 25% with the D form.
>
> But does adderall have slower onset? or faster?
>
> Just general info thanks.hello there, chemist here....adderall is a racemate comprised of l-amphetamine and d-amphetamine sulfate salts: these compounds are not isomers. they are enantiomers. also, the ratio of d-amphetamine to l-amphetamine is 3:1 in adderall, not 1:3 as noted above. for immediate-release, expect peak plasma concntrations of both compounds between 3 and 5 hours. for the extended release, 5-9 hours for t_{max}. all the best, chemist
Posted by Shawn. T. on July 23, 2004, at 17:52:43
In reply to Re: whats the diff. between adderall and dexedrine » 1980Monroe, posted by chemist on July 23, 2004, at 9:05:25
Forgive me for splitting hairs, but an enantiomer is an (optical) isomer.
Shawn
Posted by SLS on July 23, 2004, at 18:08:07
In reply to Re: whats the diff. between adderall and dexedrine » chemist, posted by Shawn. T. on July 23, 2004, at 17:52:43
> Forgive me for splitting hairs, but an enantiomer is an (optical) isomer.
>
> ShawnThanks for keeping an (optical) organ on us.
:-)
- Scott
Posted by chemist on July 23, 2004, at 18:21:57
In reply to Re: whats the diff. between adderall and dexedrine » chemist, posted by Shawn. T. on July 23, 2004, at 17:52:43
> Forgive me for splitting hairs, but an enantiomer is an (optical) isomer.
>
> Shawnhello there, chemist here...actually, a d- or l- designation tells us that there are two compounds that are chiral and interact with polarized light in different ways (rotation relative to laboratory axis): this does indicate that the compounds in question are not achiral and are, in fact, enantiomers, as you note.but we need not go directly to optics in order to answer the question: an enantiomer is a stereoisomer with the specific condition that the mirror images of the compounds are non-superposable. the d- and l- forms of amphetamine are, of course, chiral at the alpha carbon and cannot be superposed. hence, we can work with the simpler definition of enantiomer without getting into optics or the nomenclature of fischer or cahn et al., the former being troublesome and the latter, in my opinion, being of more utility. all the best, chemist
Posted by SLS on July 23, 2004, at 18:42:40
In reply to Re: whats the diff. between adderall and dexedrine » Shawn. T., posted by chemist on July 23, 2004, at 18:21:57
> hello there, chemist here...actually, a d- or l- designation tells us that there are two compounds that are chiral and interact with polarized light in different ways (rotation relative to laboratory axis): this does indicate that the compounds in question are not achiral and are, in fact, enantiomers, as you note.but we need not go directly to optics in order to answer the question: an enantiomer is a stereoisomer with the specific condition that the mirror images of the compounds are non-superposable. the d- and l- forms of amphetamine are, of course, chiral at the alpha carbon and cannot be superposed. hence, we can work with the simpler definition of enantiomer without getting into optics or the nomenclature of fischer or cahn et al., the former being troublesome and the latter, in my opinion, being of more utility. all the best, chemist
Will enantiomers differing at only one chiral center always rotate polarized light in opposite directions?When do scientists decide to use the d,l optical nomenclature as opposed to the r,s configuration designation, and why? Is it a matter of not knowing the molecular structure?
- Scott
Posted by chemist on July 23, 2004, at 19:20:29
In reply to Re: whats the diff. between adderall and dexedrine, posted by SLS on July 23, 2004, at 18:42:40
> > hello there, chemist here...actually, a d- or l- designation tells us that there are two compounds that are chiral and interact with polarized light in different ways (rotation relative to laboratory axis): this does indicate that the compounds in question are not achiral and are, in fact, enantiomers, as you note.but we need not go directly to optics in order to answer the question: an enantiomer is a stereoisomer with the specific condition that the mirror images of the compounds are non-superposable. the d- and l- forms of amphetamine are, of course, chiral at the alpha carbon and cannot be superposed. hence, we can work with the simpler definition of enantiomer without getting into optics or the nomenclature of fischer or cahn et al., the former being troublesome and the latter, in my opinion, being of more utility. all the best, chemist
>
hello there, chemist here.....if you are talking about a pair of stereoisomers with one - and only one - chiral center, you are, by definition, talking about a pair of enantiomers which will indeed be differentiated by +/- rotation of plane-polarized light. R and S do NOT correlate with optical activity or +/- rotation of plane-polarized light. R and S designations are not subject to misinterpretations as fischer projections can be: as you note, R and S simply differentiate absolute configurations (spatial) of molecules. this is useful in accord with IUPAC naming conventions, which do not (alone) indicate whether or not one or more chiral centers are present. i work with nicotine extensively, and (S)-nicotine binds with a higher affinity to the neuronal nicotine receptor alpha_{7} homopentameric and alpha_{4}beta_{2} heteropentameric subtypes than does (R)-nicotine. because i am a theorist, and there the allosteric nature of the binding in this case, i am interested in derivatives of (S)-nicotine and not (R)-nicotine. i can tell by looking at a ball-and-stick model whether or not it is R or S: i cannot tell if it is d- or l-. the R and S is more useful in this regard, because a putative (or known) structure can be classified instantly without going into the laboratory. further, if i can designate R and S configurations, then i know that the molecule is chiral and optically active, and i still have not gone into the lab. the only remaining issue is whether R = d or l or, alternatively, S = d or l, and this is determined in the lab. all the best, chemist
>
> Will enantiomers differing at only one chiral center always rotate polarized light in opposite directions?
>
> When do scientists decide to use the d,l optical nomenclature as opposed to the r,s configuration designation, and why? Is it a matter of not knowing the molecular structure?
>
>
> - Scott
Posted by Shawn. T. on July 23, 2004, at 19:37:44
In reply to Re: whats the diff. between adderall and dexedrine » Shawn. T., posted by chemist on July 23, 2004, at 18:21:57
I was just noting that an enantiomer is an example of an optical isomer; I wasn't trying to define it. Of course, an optical isomer could also be a diastereoisomer.
Shawn
Posted by chemist on July 23, 2004, at 19:48:14
In reply to Re: whats the diff. between adderall and dexedrine » chemist, posted by Shawn. T. on July 23, 2004, at 19:37:44
> I was just noting that an enantiomer is an example of an optical isomer; I wasn't trying to define it. Of course, an optical isomer could also be a diastereoisomer.
>
> Shawnyes, i know, i actually work with protonation-induced diastereomerism of certain alkaloids.....thanks for the dialog.....in colclusion, i think the most useful piece of information to emerge from this thread is that the ratio of the higher affinity d-amphetamine to the lower affinity l-amphetamine in adderall was initially reported to be 1:3 when in fact it is 3:1......all the best, chemist
Posted by chemist on July 23, 2004, at 21:35:40
In reply to Re: whats the diff. between adderall and dexedrine » Shawn. T., posted by chemist on July 23, 2004, at 19:48:14
hello there, chemist here.....i went back to 1980monroe's post and realized i misinterpreted - monroe is/was correct in that the ratio d-amphetamine to l-amphetamine in adderall is3:1. i apologize and will (lamely) invoke the ``that's the kind of answer i give when i get up at 5:20 a.m. every morning.'' so shawn, sls, monroe, and all others, i am sorry for the digression based upon my own error. i will endeavour not to err again, although history has shown that this undertaking will likely be undermined by yours truly......again, apologies, and best to all.....chemist
Posted by Cressida on July 24, 2004, at 3:44:53
In reply to oops, ratio was right! » chemist, posted by chemist on July 23, 2004, at 21:35:40
Yep, both Adderall immediate-release and Adderall-XR contain d-amphetamine and l-amphetamine salts in a 3:1 ratio.
The thread thus far or Chemist have probably already explained, but the major difference between Adderall and Dexedrine is that Adderall ALSO contains racemic amphetamine, which is a 50/50 combination of dextroamphetamine and levamphetamine. These amphetamines are molecular mirror images or optical isomers. Levamphetamine, the L-isomer, is mainly a *cardiovascular system stimulator* rather than a cerebral stimulant. So, Adderall affects both the CNS (central nervous system) and PNS (peripheral nervous system).
If anyone would like to read more on Adderall visit the URL below. It points to the official prescribing information for the extended-release formulation. You will need the Acrobat Reader.
http://www.adderallxr.com/pdf/full_prescribing_information_1002.pdf
Posted by badmood on July 24, 2004, at 14:00:50
In reply to Re: Key Difference (probably a review), posted by Cressida on July 24, 2004, at 3:44:53
I know they did about 50 years ago for depression.
Also they advertised Dexamyl when they combined Amytal (amobarbital) to keep the anxiety down, which was combined with dextroamphetamine for depression also. Anyways...
Adderall is amphetamine too, but they advertise it like its Strattera. Well actually i havent seen any advertisementss for Immediate Release Adderall, they had a bunch of those back in '96 when it came out, now its mostly Adderall XR.
But does anyone know why?
Posted by Cressida on July 24, 2004, at 17:24:05
In reply to Re: why dont they advertise dexedrine?, posted by badmood on July 24, 2004, at 14:00:50
I've seen commercials for a few antidepressants and the non-stimulant Strattera. You'll probably never have the pleasure of viewing a commercial for any highly controlled substance like Adderall, Dexedrine, Focalin or Ritalin. You may see an advertisement for one in a professional journal or prescribing reference magazine. I don't know the reason, but I can guess that either a drug has gone off patent (less profit potential) or has a high rate of abuse. If someone has a better explanation please post. Cheers.
Posted by badmood on July 24, 2004, at 18:13:35
In reply to Re: why dont they advertise dexedrine?, posted by Cressida on July 24, 2004, at 17:24:05
http://amphetamines.com/dexedrine.html
Kinda funny doc's actually at one time liked Amphetamine, but ofcourse years go by they usally lose favor.
Also here's Dexamyl, amobarbital and dextroamphetamine, around the 50's or 60's, dont you notice they always had a smile on there face. Must of been truly a pep pill. :
http://amphetamines.com/dexamyl.html
Ha.... Here's a Ritilin AD, back in the day when it was popular as Strattera.
Posted by sb417 on July 25, 2004, at 1:19:00
In reply to whats the diff. between adderall and dexedrine, posted by 1980Monroe on July 23, 2004, at 8:36:20
Chemist and Shawn T:
I just want to say that we're very fortunate to have both of you here. I learn so much from your posts. Chemist, I was sorry to see what you were subjected to a few months ago. Frankly, I was surprised that you chose to stay here after that "witch hunt" type of treatment you received here. You seem like a mature, gracious person.
Thanks to both of you for helping us.
sb
Posted by chemist on July 25, 2004, at 13:47:11
In reply to Chemist and Shawn T., posted by sb417 on July 25, 2004, at 1:19:00
hello there, chemist here....thank you for the kind words....i am but one small (and frequently malfunctioning, as evidenced by my ``oops'' above; there are numerous times i have been off-base, and i thank any/all who show me the light) part of the machine. as for witch hunts, well, nipped in the bud. the current one is far more damaging to this community....in any event, be well, and all the best, chemist
> Chemist and Shawn T:
>
> I just want to say that we're very fortunate to have both of you here. I learn so much from your posts. Chemist, I was sorry to see what you were subjected to a few months ago. Frankly, I was surprised that you chose to stay here after that "witch hunt" type of treatment you received here. You seem like a mature, gracious person.
>
> Thanks to both of you for helping us.
>
> sb
Posted by sb417 on July 25, 2004, at 18:07:35
In reply to Re: Chemist and Shawn T. » sb417, posted by chemist on July 25, 2004, at 13:47:11
> hello there, chemist here.... as for witch hunts, well, nipped in the bud. the current one is far more damaging to this community....
>Oh, dear. I wasn't aware of yet another one going on. Sometimes ignorance is bliss.
Posted by chemist on July 25, 2004, at 18:10:08
In reply to Re: Chemist . » chemist, posted by sb417 on July 25, 2004, at 18:07:35
> > hello there, chemist here.... as for witch hunts, well, nipped in the bud. the current one is far more damaging to this community....
> >
>
> Oh, dear. I wasn't aware of yet another one going on. Sometimes ignorance is bliss.hello there, chemist here...i just realized that my statement might imply i am yet again being hounded: that is not the case. i apologize for any misconception. the only person tripping me up these days is myself!!! all the best, chemist
Posted by utopizen on July 26, 2004, at 12:44:02
In reply to Re: why dont they advertise dexedrine?, posted by badmood on July 24, 2004, at 14:00:50
dEXEDRINE can cause depression, according to my psychopharmacology book on the stimulants, called Stimulants.
I'd explain, but it's a complicated thing involving stuff.
This is the end of the thread.
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