Omeprazole
"I don't know if anyone has this problem, but I don't have the classic symptoms of heartburn, but my doctor thought my vocal cord problems could be cause by acid reflux.  So I took this for about 4 days.  On the fifth day I started having a terrible burning sensation that would not go away and lasted all day.  It happened again the next day also.  I decided to stop taking it and it has gone away.  Anyway I'm not going to take it anymore and check with my doctor for something else. I went from having no symptoms to terrible burning sensations so I'm stopping for now."