Amoxicillin / clavulanate
"I have taken regular amoxicillin before, but my DR put me on this to clear up a sinus infection. BCBS covered it and I took one dose when RX was filled with yogurt, milk, and chicken soup and 2 hrs later had intense diarrhea and I vomited every 2-3 minutes from 4 pm to 9:30 pm. I thought I was literally going to die or have to have my stomach pumped or something. Made me severely dehydrated and from all the vomiting I had the most intense stomach pain I have ever felt in my life. Going in for a  shot today and getting off this medication."