Vyvanse Dosage/d-amphetamine Equivalent Question

[WithoutaPlan]

After reading the prescribing sheet and a lot of forum messages, I have a good idea of how Vyvanse works and converts to dextroamphetamine in the gut. However, nowhere do I see that X mg of Vyvanse is equivalent to Y mg of dextroamphetamine sulfate.

Does anyone have this information? Is 30 mg of Vyvanse the same as taking 30 mg of Dexedrine evenly throughout the day? I assume not as Vyvanse has greater bioavailability supposedly.

Has anyone had experience with taking both medications and have any anecdotal information about perceived effectiveness of one versus the other?

[adhd85]

This is a very good question and I am also curious about this as well. Vyvanse was first marketed as 30mg, 70mg. It looks like 70mg is the highest. Adderall XR is highest at 30mg. Dexedrine spansules, from what I know, is highest at 15mg. Whether or not these are equivalent dosages is beyond me. I just started vyvanse and took 2x30mg pill yesterday and just today tried 3x30mg pills...I'll report on any difference I notice.

[Tylerlee17]

70mg of Vyvanse is roughly equivilant to 30mg Adderall XR (According to Shire). 30mg of Adderall XR is roughly 22.50mg Dextro-amphetamine (75%).

30mg Vyvanse = 7.50mg D-Amphetamine
50mg Vyvanse = 15.00mg D-Amphetamine
70mg Vyvanse = 22.50mg D-Amphetamine

You take a Spansule and the Medication hits you faster and last a shorter duration. Taking Vyvanse I remember it felt like it took 1 1/2 to 2 hours to kick in but when it did it would last nearly 10-12 hours (was on 100mg / day). Adderall XR is 75% Dextroamphetamine 25% Levoamphetamine, if you have a question regarding vyvanse doses versus D-Amphetamine just find out the equivilant dose of Adderall XR and multiply the total adderall dosage by 0.75 and you have the amount of d-amphetamine equal to the vyvanse dosage.

[Matt S.]

According to Wikipedia, 25 mg of Vyvanse contains the same amount of dextroamphetamine as a 10 mg Dexedrine Spansule, whether it is accurate, who knows???

[JR1973]

TylerLee,

Where did you find that info at? I've been searching high and low with no luck.

thanks,
J

[pbgarcia]

Im not sure ...im on vyvanse now ..but for the most part from what I do know , its not the same dexadrine, and I found out the name for the generic for vyvanse ...and thats not the same . If you can just get the original vyvanse it would be better for you ...


I hope I could help a little !

[Tylerlee17]

I'm a chem/pharm major. Adderall is composed of 75% Dextroamphetamine (2 Dextroamphetamine salts and 2 Racemic Mixtures). A racemic Mixture is basically an equal mixture of the two enantiomers (Levo and Dextroamphetamine) ... so If you've got 2 Racemic salts and 2 pure Dextroamphetamine salts

1/4 Dextroamphetamine Saccharate
1/4 Dextroamphetamine Sulfate
1/4 (d,l)-amphetamine Sulfate
1/4 (d,l)-amphetamine Aspartate Monohydrate

Then you end up with a total composition of 75% Dextroamphetamine Isomer and 25% Levoamphetamine Isomer roughly... I know that Dexedrine is 100% Dextroamphetamine so I used the equivilancy dosages shire provided for determining a roughly equivilant dose of Adderall XR vs Vyvanse and then just did the math to find equal it to dexedrine.

Anyone can find out how much dexedrine is equal to an adderall XR dose

75% of 10mg Adderall XR = 7.50mg right? There you go, 10mg Adderall XR has 7.50mg of Dexedrine (Dextroamphetamine) active in it. We know that 10mg Adderall XR (according to shire anyway) equals 30mg of Vyvanse so you can only logically assume that 30mg Vyvanse has roughly 7.50mg of Dexedrine active at any given time.

[ventyourpain2k5]

I ran some numbers:
30mg Vyvanse = 8.9mg d-amp
50 = 14.8
70 = 20.8

[Mincan]

So why do people want to be on Vyvanse again? What are its benefits over Adderall or Dexedrine?

[GuardianAngel]

Single dose, slower smoother pharmcokenetic curve, 12+ hr effectiveness, few side effects VS other Stimulant meds, much lower possiblity of abuse.


and the big one for me

It works for me, controls my ADD without making me jumpy, irritable, or giving me a giant buzz.

[Mincan]

Ah, excellent!

[HighFunctioning]

Originally Posted by ventyourpain2k5

I ran some numbers:
30mg Vyvanse = 8.9mg d-amp
50 = 14.8
70 = 20.8

Another thing to remember is that when comparing doses (if that's even meaningful), one has to compare d-amphetamine base to d-amphetamine-base. 30mg of dextroamphetamine sulfate is supposedly around 22mg dextroamphetamine, so 70mg of Vyvanse is probably equivalent to something like 28mg of dexedrine, provided that the above numbers are correct and are with respect to the base molecule.

[Tylerlee17]

Originally Posted by HighFunctioning

Another thing to remember is that when comparing doses (if that's even meaningful), one has to compare d-amphetamine base to d-amphetamine-base. 30mg of dextroamphetamine sulfate is supposedly around 22mg dextroamphetamine, so 70mg of Vyvanse is probably equivalent to something like 28mg of dexedrine, provided that the above numbers are correct and are with respect to the base molecule.

This is where you're gonna need a chem lab set up with a lot of free time

[WithoutaPlan]

This is all very good information. I am aware, though that this equivalency business is very rough. You mention Vyvanse 70 mg is reported to be equivalent to Adderall XR 30 mg so that's a good starting point and you have made some good analysis following that. The part that's rough about these things are that we all react differently to the medications to some degree given all things being equal about the medication. Also, the method of activation and absorption of Vyvanse is different. However, various additives change the way things work for us and apparently, even inactive ingredients seem to alter the effects as some people report differences from brand to brand.

At this point, I've finally settled on Adderall XR 30 as my body seems to have acclimated to the PNS effects of the racemic blend and I find that I get good focus and can direct my attention as required. Initially, the XR 20 mg dosage seemed to just cause physical stimulation with minimal help in the area I need help with. I believe the 30 mg works better for me because the 30 mg dose has more of the active ingredient - dextroamphetamine. Fortunately, the added amount of l-amphetamine doesn't seem to increase the amount of PNS or I'm just used to it now and don't notice it.

My preference would be to just use the cheaper dextroamphetamine throughout the day but that is not an option with my doctor. If Vyvanse is approved for Adult ADHD, then I'll probably give it a shot starting at 70 mg/day as I'd like the longer-acting effect.

[GuardianAngel]

= 35 and on vyvanse, so i am certain it has been apporved for adults