If you are prescribed Vyvanse you will get a list of all the horrible things that can happen to you while you are taking it. This sheet of paper will tell you not to take Vyvanse with orange juice or grapefruit juice since these will inhibit the drugs absorbtion. So you will take you're Vyvanse with some tea or maybe the milk left in your cereal bowl in the morning. And if you're like me you will then take off to work with a Diet Sunkist and then proceed to pee 10 times in a six hour period. Really.
Turns out that certain chemicals that make your urine acidic (like soda which is all way acidic) bonds with the drug and makes your body flush it out so it won't work and you'll visit all three bathrooms that you know of in your building. You know, to keep it fun!
Of course this is something I learned after poking around some ADHD forums and RxList.com and not from the pamplet they gave me at the drugstore. So here I sit feeling mildly better than yesterday with tea to drink instead of my last Diet Sunkist. So if you take Vyvanse don't drink soda during the day, it will make you pee like crazy and drain all that pricey medication out of your system.