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Fluoroquinolone Antibiotic

Ciprofloxacin

Brand names: Ciproxin

Ciprofloxacin is a fluoroquinolone antibiotic with broad Gram-negative activity, used for urinary, respiratory, gastrointestinal and certain other infections including those caused by Pseudomonas.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

It inhibits bacterial DNA gyrase (topoisomerase II) and topoisomerase IV, preventing DNA replication and leading to bacterial cell death.

Prescribing in practice

  • MHRA warns of disabling and potentially irreversible tendon, musculoskeletal and neuropsychiatric reactions; stop at the first sign of tendon pain or inflammation and avoid in patients at high risk.
  • It prolongs the QT interval and can cause aortic aneurysm/dissection, so use caution with other QT-prolonging drugs and in those with aneurysm risk factors.
  • Ciprofloxacin inhibits CYP1A2 and markedly raises theophylline and tizanidine levels; it also potentiates warfarin and chelates with calcium, antacids and iron.

Monitoring

Monitor for tendon, neurological and psychiatric symptoms throughout treatment, and review interacting drugs such as theophylline and warfarin.

Counselling the patient

  • Stop and seek advice immediately if you develop tendon pain or swelling.
  • Avoid taking it at the same time as dairy products, antacids or iron, which block absorption.
  • Report new numbness, tingling, mood changes or palpitations.

Evidence & guidelines

The MHRA has issued repeated safety warnings (2019 and 2023) restricting fluoroquinolone use because of the risk of long-lasting and disabling adverse effects.

Reference: MHRA Quinolone Safety Update 2018/2019; NICE NG112 (UTI in Adults); Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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