Ciprofloxacin
A fluoroquinolone antibiotic, more active against Gram-negative than Gram-positive bacteria, for urinary and gut infections and typhoid.
Drug card
- Class
- Fluoroquinolone
- How it works
- Blocking DNA gyrase and topoisomerase IV, so bacteria cannot copy their DNA
- Used for
- Urinary tract and kidney infections
- Infectious diarrhea
- Typhoid fever
- Bone and joint infections
- Known for
- Tendinitis and tendon rupture
- Its name
- -floxacin means a fluoroquinolone antibiotic
Study it as a flashcard, and it comes back before you forget it.
Mechanism of action
How does ciprofloxacin work?
Blocks bacterial DNA gyrase and topoisomerase IV and kills the bacteria. It is more active against Gram-negative than Gram-positive bacteria and covers Pseudomonas aeruginosa. It also inhibits the liver enzyme CYP1A2, which raises the levels of drugs cleared by it.
Like other fluoroquinolones: Fluoroquinolones block DNA gyrase and topoisomerase IV, two bacterial type II topoisomerases (gyrase is topoisomerase II). The bacterium needs both to copy, transcribe and repair its DNA, so blocking them halts DNA replication and kills the cell: the drugs are bactericidal. Bacteria resist them mainly through gyrase mutations, a less permeable outer membrane or efflux pumps.
Uses
What is ciprofloxacin used for?
- Urinary tract and kidney infections
- Infectious diarrhea
- Typhoid fever
- Bone and joint infections
- Abdominal infections, with metronidazole
- Eye infections, as eye drops
Side effects
Side effects of ciprofloxacin
- Tendinitis and tendon ruptureKnown forSerious
- Nausea
- Diarrhea
- Vomiting
- Rash
- Peripheral neuropathySerious
- SeizuresSerious
- Mood changes, psychosis or suicidal thoughtsSerious
- Liver injury, rarely liver failureSerious
- Joint problems in children
- Kidney inflammation or failureSerious
- Severe skin reactions (SJS, TEN)Serious
Known for marks what an exam expects you to know it for.
Watch for
Cautions and what sets it apart
- Never with tizanidine; it also raises theophylline levels, because it blocks CYP1A2.
- Space doses apart from antacids, iron, zinc, and milk or other calcium-rich foods and drinks.
- Children: used only for complicated urinary infections, anthrax exposure and plague.
Good to know: Not a first choice for pneumococcal pneumonia. Levofloxacin and moxifloxacin are licensed for it, including multidrug-resistant pneumococci.
Remember it
A way to remember it
STAMP
- S
- Sugar swings: low or high blood sugar
- T
- Tendinitis and tendon rupture
- A
- Aortic aneurysm or dissection
- M
- Myasthenia gravis made worse
- P
- Peripheral neuropathy
Fluoroquinolones can leave a STAMP on the body: these are the serious harms in their label warnings.
Written for biofideX
Its name
-floxacin means fluoroquinolone antibiotic
WHO's stem is -oxacin (quinolones); -floxacin is its fluorinated subgroup: ciprofloxacin, levofloxacin, moxifloxacin. Nalidixic acid, the parent quinolone, has no stem.
- Every drug name stem
Its class
Fluoroquinolones
Other fluoroquinolones with a card:
Easily mixed up with topoisomerase II inhibitors and tetracyclines.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.
Antibiotics: DNA, folate and tuberculosis
Ciprofloxacin is one of 11 drugs practiced together here: their classes, how they work, what they treat and what they're known for.
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