Why did I throw up after working out?

I had not ate any food yet and drank half a can of lemonade. Then I took 200mg of caffeine and 8mg of ephedrine 2.25 hours before working out in the morning. In the middle of working out I felt dizzy and ended up going to the washroom to throw up. I couldn't stop myself from throwing up. Why is this? Is it because I didn't eat? Or maybe it was the ephedrine? Or both? Please explain. I have taken more ephedrine and caffeine before without exercising but have never threw up or had the feeling of throwing up. And, normally when I do feel like throwing up I can keep it in. Thanks for your help.