bacterial infection
"I am taking 500mg 3 times a day for 7 days. Side effects started day 1 with extreme nauseous. By day 2 I couldn't keep any food down, was constantly nauseous and had a major headache. Today is day 3 and I've barely been able to walk around I feel so weak, and the nausea is even worse. Fingers crossed day 4-7 will have better results."