Clindamycin
"I took this last year for a severe bacterial infection on my chin last year.  It certainly did it's job with clearing up the infection. HOWEVER, I will NEVER be taking this medication again if something similar happens in the future. The side effects I experienced were absolutely excruciating! I had heartburn that made me feel like I was going to die- a sharp pain that felt like a lump in my chest that was stabbing me from the inside. My family thought that I was just being dramatic, but after reading some reviews on here, I know a lot of people have had similar experiences. I took the drug 4x a day, and ended up gaining weight on it, because the only thing that helped dull the pain was eating a TON of food with it."