Ciprofloxacin
- Class: Fluoroquinolone
- Used for: a bacterial infection
- Say it: sip-roh-FLOX-uh-sin
- Forms: tablet, oral liquid, injection, eye drops
Fluoroquinolones block DNA gyrase. They also carry boxed warnings for tendon rupture and nerve damage, which is why they are no longer a casual first choice.
The stem marks a fluoroquinolone, blocking DNA gyrase so the bacterium cannot copy itself. The class warning travels with the stem too: tendon rupture, aortic aneurysm, nerve damage and QT prolongation, which is why these are no longer first choice for a simple infection. All drug suffixes ›
Side effects
Common: nausea, diarrhea, dizziness
Serious: tendon rupture, nerve damage
Typical dose
250–750 mg twice daily
The range spans a threefold difference: 250 mg twice daily for simple cystitis, 750 mg twice daily for bone or joint infection. Reduce in renal impairment.
Check yourself
Which patient has the highest risk of tendon rupture on ciprofloxacin?
- A 70-year-old who also takes prednisone
- A 30-year-old on no other medication
- Someone who takes it with food
- Someone with a penicillin allergy
Show answer
A. A 70-year-old who also takes prednisone
Older age and corticosteroids are the two established risk multipliers, and together they are additive. The risk is real enough that fluoroquinolones are reserved when another option exists.
See it, don't memorize it
The app has the mechanism comic and a patient case for Ciprofloxacin – plus the name link, the class mnemonic, pronunciation you can hear, and a self-check, for the top 100 drugs. One purchase, no subscription, no account.