Ciprofloxacin: what it treats and how to use it safely

Ciprofloxacin is a widely used antibiotic that kills many kinds of bacteria. Doctors prescribe it for infections like complicated urinary tract infections, certain types of gastroenteritis, some respiratory infections, and skin or soft-tissue infections. It works by blocking bacterial enzymes (DNA gyrase and topoisomerase IV) so bacteria can't copy themselves. That makes it fast and effective in the right situations.

Even though ciprofloxacin works well, doctors now use it more carefully because of rare but serious side effects. If your prescriber offers other options for a mild infection, ask why ciprofloxacin is the best choice for you.

Common dosing and practical tips

Typical adult doses vary by infection: for many UTIs it's 250–500 mg twice daily; for more serious infections higher doses or IV formulations may be used. Always follow the exact dose and length your doctor gives you. Take pills with a full glass of water and swallow them whole. Finish the entire course even if you feel better, because stopping early can let the infection come back and breed resistance.

Keep a gap with certain minerals and antacids. Ciprofloxacin binds to calcium, magnesium, aluminum and iron, which cuts absorption. Take ciprofloxacin at least 2 hours before or 6 hours after antacids, iron or zinc supplements, and some calcium products. Avoid large amounts of dairy at the same time as the pill.

Side effects, warnings and drug interactions

Mild side effects include nausea, diarrhea, headache, and dizziness. Stop the drug and contact your doctor if you get severe diarrhea, a rash, or signs of an allergic reaction. More serious but rare risks are tendon pain or rupture (especially Achilles tendon), peripheral neuropathy (numbness or burning), and mood or memory changes. If you notice sudden tendon pain, stop taking the medicine and get medical advice right away.

Ciprofloxacin can interact with common drugs. It can raise levels of theophylline and caffeine, and it may increase warfarin effect—so INR checks matter if you use warfarin. It also affects certain heart rhythm drugs; tell your provider about all medicines and supplements you use. Pregnant people, breastfeeding people, and young children usually avoid ciprofloxacin unless there’s no safer option.

Store the medicine at room temperature away from moisture. Avoid heavy alcohol while you’re taking it if alcohol makes you dizzy or sick. If you have kidney problems, your dose may need adjusting. When in doubt, ask your pharmacist or prescriber—quick questions now can prevent big problems later.

Want to know more about when ciprofloxacin is right for you? Bring a list of your symptoms, other meds, and allergies to your next appointment and ask whether a narrower antibiotic could work instead.