You may feel tied or irritable a few hours after taking Vyvanse. Learn about "Vyvanse crash," including what it is and how to avoid it. Subscribe. Vyvanse Crash: What It Is and How to Deal with It. In May I changed to Vyvanse, I was taking 100 mg/day of Ritalin and it just was not working at all, plus insurance wanted me to switch to generic-horror. I’ve been on 2 X 60mg Vyvanse per day, morning and afternoon, plus 15mg dexamphetamine as booster for evening.

Find a dosing guide for children about the different strengths of Vyvanse® (lisdexamfetamine dimesylate) in capsule and chewable tablets. Vyvanse® ranges from 10 mg to 70 mg and can be chewed, mixed, or swallowed.