I was just recently prescribed Adderal (25mg) for adhd, and I want to know a few things. 1. Is it okay to take adderal before giving blood. I take them before school and I signed up to donate blood at 11:45 tomorrow. 2. I want to go to an amusement park today at around 7:00 After giving blood and with adderal in my system am I at any risk? 3. I know marijuana is illegal, and I know the facts about it. I also know it increases your heart rate, as does adderal, as does amusement park rides, added to the fact that I donated blood. Is there any lethal risk involved?