Reviewed by MedNext Clinical Team
Fluoroquinolones, including ciprofloxacin, levofloxacin, and moxifloxacin, were once considered a broadly safe and convenient antibiotic class. Regulatory agencies worldwide have now updated their guidance to restrict fluoroquinolone use to situations where other options are inappropriate, following mounting evidence of serious and potentially irreversible adverse effects [1].
Tendon Rupture and Musculoskeletal Toxicity
The association between fluoroquinolones and tendon rupture — most commonly the Achilles tendon — is well established. The risk is highest in patients over 60 years of age, those concurrently taking corticosteroids, and patients with renal impairment. Tendinopathy can occur within 48 hours of starting treatment and has been reported weeks after completing a course [1]. Any patient reporting tendon pain during fluoroquinolone therapy should discontinue immediately and be assessed.
Aortic Aneurysm and Dissection
More recently, regulatory warnings have highlighted an association between fluoroquinolone use and aortic aneurysm or dissection, particularly in elderly patients and those with pre-existing aortic disease. This should be considered when selecting antibiotics for patients with known aortic pathology or significant cardiovascular risk factors.
Peripheral Neuropathy
Fluoroquinolone-associated peripheral neuropathy can develop within days of starting treatment and may persist long after discontinuation, or even become permanent. Symptoms include burning, shooting pain, tingling, or numbness in the extremities. Prescribers should warn patients to report these symptoms and discontinue the antibiotic promptly if they occur.
QT Prolongation
Fluoroquinolones prolong the QT interval, which can precipitate life-threatening arrhythmias including torsades de pointes. The risk is compounded by co-administration with other QT-prolonging drugs (e.g., antipsychotics, antiarrhythmics, macrolides) and by electrolyte abnormalities such as hypokalaemia or hypomagnesaemia. A baseline ECG and electrolyte check are advisable before prescribing in high-risk patients.
Restricted Use: Appropriate Indications
Given these risks, fluoroquinolones should be reserved for situations where the benefit genuinely outweighs the harm — such as complicated urinary tract infections, certain respiratory infections in patients with limited alternatives, and travellers' diarrhoea in specific circumstances. Routine use for uncomplicated UTIs, where safer first-line agents are available, is no longer justified.
References
- Patel H, et al. Systematic review of the safety of fluoroquinolone use in clinical practice. Drug Saf. 2019;42:983-992.