Vivarin is a non-perscription caffeine drug used for mental and bodily allertness. Overdosing could lead to extremley fast heart beat and nervousness. Also can cause shaking. One pill is equal to about one cup o'joe.
When my friend and I were taking Vivarin, we were really allert and i was shaking like crazy. It was kinda like i was high or something. She got really sick and puked because she took one too many.