Metformin
"This drug can kill you.  One of the worst reactions to a medication that I've ever experienced.  Last Saturday, I could hardly walk out of a store as the muscle contractions grew worse and the pressure in my chest increased.  And ER visit followed and a week later, I am still weak.  It did not get out of my system in 24, 48 nor 72 hours.  Watch this drug closely when you are given it for treatment, especially if you have already had physical symptoms that are similar to some of its side effects.  And yes, I had the diarrhea, the spasms which ran up into my torso and the nausea but I tried working through it all.  I could barely lift my arms last Saturday and I was in pain from my feet to the top of my head.  There was no comfortable place"