I've been switched from biaxin to cipro (ciprofloxacin) to treat middle ear infection because biaxin didn't help me. i need to take it for 7 days. is this enough?

Usually enough: Usually a seven day course of Cipro (ciprofloxacin) would be enough to treat the infection if the cause is bacterial and it is sensitive to Cipro (ciprofloxacin). Since it did not respond to Biaxin, I encourage you to follow-up with your physician at the end of treatment to make sure things are clear. You may still have a little fluid left in the ear, but the redness and cloudiness should have cleared up.