Azithromycin
"I have chlamydia. My doctor prescribed me this medication (two 500mg to be accurate. 
I don't know why people are complaining of vomit and diarrhea, I would consider myself a person with a weak stomach. I get nauseous easily over anything. This medication did not give me any side effects. 

I took the two pills at the same time then ate some food (not a lot) a couple hours later I lost my appetite but I felt fine besides that. 
 Without insurance the retail price for this is about $40."