Vyvanse is a federally controlled substance (CII) because it contains lisdexamfetamine dimesylate that can be a target for people who abuse prescription medicines or street drugs. Keep Vyvanse in a safe place to protect it from theft. Never sell or give your Vyvanse to anyone else because it may cause death or harm to them and it is against the law. Who should not take Vyvanse? Do not take Vyvanse if you or your child are: allergic to amphetamine products or any of the ingredients in Vyvanse. See Medication Guide for a list of ingredients. taking, or have stopped taking in the last 14 days, a medicine called a Monoamine Oxidase Inhibitor (MAOI). being treated with the antibiotic linezolid or intravenous methylene blue. Vyvanse may cause serious side effects, including: Heart-related problems including: sudden death, stroke, and heart attack in adults; sudden death in children who have heart problems or heart defects; increased blood pressure and he...