Head-to-head comparisons of medication uses, side effects, warnings, and more.
Key takeaways
Metronidazole (Flagyl) and ciprofloxacin (Cipro) are both antibiotics used to treat bacterial infections, but they belong to different medication classes. Metronidazole is a nitroimidazole antibiotic, while ciprofloxacin is a fluoroquinolone antibiotic. Both medications can treat certain types of bacterial infections, but ciprofloxacin is also used for urinary tract infections (UTIs) and anthrax exposure, which metronidazole is not approved for. Metronidazole is typically taken three times a day, whereas ciprofloxacin is usually taken twice daily. Both medications are available as a lower-cost generic and come in tablet, oral liquid, and injectable forms. Common side effects of metronidazole include nausea and a metallic taste, while ciprofloxacin can cause nausea and diarrhea. Ciprofloxacin has more serious potential side effects, such as tendon rupture and nerve damage, and it interacts with many medications, including supplements like calcium and iron. Both medications require you to avoid alcohol, but ciprofloxacin also requires caution with sun exposure due to increased skin sensitivity.