I used to take Levaquin in the past for sinusitis but it didn't help me. Only Cipro (ciprofloxacin) helps. How is this possible that only Cipro (ciprofloxacin) helps?

Cipro (ciprofloxacin) and Levaquin. are both fluoroquinolone antibiotics and have a very close spectrum. The only explanation would be that you were infected with bacteria that is sensitive to Cipro (ciprofloxacin) but resistant to Levaquin, a rare occurrence. .