Stimulants How do you convert Vyvanse dosages to the equivalent Dexedrine Spansule doseage?

[mango33]

My insurance company charges me an outrageous co-pay for Vyvanse and asked me to talk to my doctor about Dexedrine Spansule (dextroaphetamine extended-release). Dexedrine Spansule has generic version that is much cheaper, but my doctor has never heard of it nor has my pharmacy.

Right now I take 20mg of Vyvanse in the morning and 5 mg of Dexedrine (dextroaphetamine instant-release) in the afternoon.


Can anyone help advise how to talk to my psychiatrist about the medication and the change in dosage (Dexedrine Spansule only comes in 5, 10, and 15 mg formulations)

 

[Keif' Richards]

Hey man, luckily, this is a fairly easy one. 30mg Lisdexamphetamine (Vyvanse) typically converts to 8.85mg Dextroamphetamine. Bear in mind that there is timed release at play here, but the spansules themselves are timed-release.

 

[CousinCocaine]

Now don't hold me too this but what I've heard is: Adderall XR is 2x the potency of Vyvanse and Dexedrine Spansules are 2x the potency of Adderall XR. So if that's true Vyvanse is 1/4 the potency of Dexedrine, which would mean your Vyvanse dosage of 20mg should be equal to 5mg of Dexedrine. The thing you have to keep in mind is that even though Vyvanse (lisdexamphetamine) is prodrug form of Dexedrine (dextroamphetamine) (which means when you take the lisdexamphetamine which is actually inactive your body converts it into active dextroamphetamine) everyone is different and the effects can vary drastically from person to person. I personally feel that just 15mg of Dexedrine is as strong or stronger than 70mg Vyvanse, but that's just me.

 

[FnX]

Hey man, luckily, this is a fairly easy one. 30mg Lisdexamphetamine (Vyvanse) typically converts to 8.85mg Dextroamphetamine. Bear in mind that there is timed release at play here, but the spansules themselves are timed-release.

Not necessarily. Lisdex has higher bioavailability than dexamphetamine sulphate, which has some variance in it's bioavailability depending on stomach pH etc as well.

 

[Ne0]

Now don't hold me too this but what I've heard is: Adderall XR is 2x the potency of Vyvanse and Dexedrine Spansules are 2x the potency of Adderall XR. So if that's true Vyvanse is 1/4 the potency of Dexedrine, which would mean your Vyvanse dosage of 20mg should be equal to 5mg of Dexedrine. The thing you have to keep in mind is that even though Vyvanse (lisdexamphetamine) is prodrug form of Dexedrine (dextroamphetamine) (which means when you take the lisdexamphetamine which is actually inactive your body converts it into active dextroamphetamine) everyone is different and the effects can vary drastically from person to person. I personally feel that just 15mg of Dexedrine is as strong or stronger than 70mg Vyvanse, but that's just me.

First day I took 50mg lisdexamphetmaine and got nice euhpria for 3 hours, after that effects diminished greatly, second day I needed somewhere 150mg to get same effect, but this time it didn't have that strong effects, third day I took 300mg and fourth day 400mg with little to no effects other than taking my opioid wd's away for 3 hours. Maybe my body doesn't convert lisdexamphetamine to dextroamphetamine? I had zero tolerance (6 month break), and took it to empty stomach. After using 4 days trying to get something out of it, I got some speed and it had very strong effect, like my tolerance was still zero even after using lisdex for many days straight. It did work sometimes but very unpredictable, maybe it just can't be abused.

 

[Kittycat5]

Its definitely harder to abuse but it can be, usually by simply taking mega doses. 400mg was at one time because that certainly qualifies? In tests of drug likeability in non-naive amp users, around 150mg was where lisdexamphetamine started to equal or surpass 40mg of dexamp (pretty sure it was IR too) in this rating. Now likeability is subjective and lisdex takes a bit longer to come on generally which for recreational use usually is frowned upon, but the data is there in this regard.

 

[Ne0]

Its definitely harder to abuse but it can be, usually by simply taking mega doses. 400mg was at one time because that certainly qualifies? In tests of drug likeability in non-naive amp users, around 150mg was where lisdexamphetamine started to equal or surpass 40mg of dexamp (pretty sure it was IR too) in this rating. Now likeability is subjective and lisdex takes a bit longer to come on generally which for recreational use usually is frowned upon, but the data is there in this regard.

Nah I think it has something to do with my body not metabolizing lisdexamphetamine to dextroamphetamine, because even mega doses didn't produce much of effects, and like said after that run street amphetamine worked like magic. I had 6 month break from amphetamines (and evne then used one day) so my tolerance was zero.

 

[Kittycat5]

Thats kinda hard to believe to be honest because the site of the cleavage of the lysine from the parent molecule to form the d-amp is in red blood cells, not the gut or liver, and its been shown to work even in things like sickle cell disease. Its remarkably consistent among patients. Im vastly simplifying here, as Ive written about this a ton in the past, but Vyvanse is not at the mercy of liver or gut enzymes or other transport systems that classically are involved in drug metabolism. Its pretty unique.

 

[Kittycat5]

Let me say, I do believe it didnt work for you, just am doubting it was because it wasnt metabolized properly.

 

[Ne0]

Let me say, I do believe it didnt work for you, just am doubting it was because it wasnt metabolized properly.

Then what would explain that I got so mild effects from it when normal amphetamines work nicely on me? I also puked lots in the same day because I went through opioid WD's, but when I took lisdex I would keep it in my empty stomach at least for 2 hours.

 

[FnX]

Then what would explain that I got so mild effects from it when normal amphetamines work nicely on me? I also puked lots in the same day because I went through opioid WD's, but when I took lisdex I would keep it in my empty stomach at least for 2 hours.

Absorption issues perhaps? Did you have opioid WD at a similar level during both times, when you took normal (dex?)amp compared to lisdex? Then again you did mention lisdexamphetamine working pretty much normally when you took 50mg after that break of yours. If you experience euphoria, you're likely dosing at a recreational level and 50mg after 6 months break could do that. Tolerance is rapid, and it's not unheard of to need 150mg to experience similar euphoria the next day.

You tried 'speed', felt a very strong effect, like your tolerance was zero, have you considered the possibility that the main ingredient in your speed wasn't actually amphetamine? How much "normal amphetamine" do you usually dose and what purity %? Also, when you talk about taking mega doses of vyvanse, you're kind of skewing the results when you slowly ramp up the dosage day by day 50mg -> 150mg -> 300mg -> 400mg I think you might reassess how you feel about lisdex if you had taken that 150mg after the 6 month break instead.

 

[TheCollegeTweaker]

All you should have to do is tell your doctor you can't afford to pay the co-pay every month.