Azithromycin
"I only found out that my VERY long term boyfriend was cheating on me because he gave me chlamydia. I took the four 250mg pills in the doctors office yesterday around 3:30. At 4 pm I had SEVERE stomach cramping. I felt nauseous and thought that maybe it was just because I didn't eat enough before taking them. I had no appetitie but I managed to eat a little bit. I have constantly felt like I was going to have diarrhea but nothing or little comes out. Today is day two and I've had wierd blurred vision and dizziness and headache  along with more cramping and stomach pain. Still no appetite and I'm extremely sleepy. It hasn't helped chlamydia symptoms- still itching and discomfort and discharge. Hopefully something will give soon."