How do you counteract dehydration caused by methylphenidate and lisdexamfetamine?

Hello, it appears that you are experiencing dehydration while taking Vyvanse. It is possible that this is due to a decrease in the production of a natural anti-diuretic hormone, however this is not reported in the literature. I suggest that you consult your doctor to make sure that there is not an underlying non-drug cause, since what you are describing is not really being reported. Additionally, if nothing else can explain the situation, a change of molecule could be tried.