Just FYI, in relation to your daughter's sinus infection (if she is still having problems), a huge number of pediatric sinus infections are actually caused by fungus, not bacteria. In fact, giving an antibiotic to treat a fungal sinus infection can just make the fungal growth worse.

So if she is still having trouble, you might want to take her to an ENT (Ear, Nose and Throat) specialist to have it checked out.

Incidentally, any medication has the potential for side effects. The package insert should also tell you the percentage of patients who experienced those problems, which is usually pretty low.