I am currently on a 10-day cycle of Omnicef for a sinus infection. Overall, the antibiotic seems to be having a beneficial effect on clearing up the infection but there are some side effects that are a little difficult to deal with. I have basically had diarhea since I started the cycle and I assume this will end with the end of the cycle. It makes life a little tricky to say the least. Another issue was that Omnicef seemed a little pricey for the 20 pills I received. I am not usually an anti-biotic taker but as for having the desired effect of helping end this sinus infection, I would say Omnicef has done what was asked.