Ask your doctor before using a stomach acid medicine (including Alka-Seltzer or sodium bicarbonate). Some of these medicines can change the way your body absorbs lisdexamfetamine, and may increase side effects.
Other drugs may interact with lisdexamfetamine, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.
 Vyvanse drug interactions (more detail)
