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Fluoroquinolone Antibiotic Pregnancy: Avoid — potential cartilage/bone effects in fetus

Levofloxacin

Brand names: Tavanic

Adult dose

Dose: CAP/hospital-acquired pneumonia: 500 mg OD–BD. UTI (complicated): 500 mg OD × 7–14 days. Skin/soft tissue: 500 mg OD–BD.
Route: Oral or IV (1:1 bioequivalent)
Frequency: OD–BD
Max: 750 mg/day
MHRA 2019: restrict fluoroquinolones — use only when other antibiotics contraindicated or failed. Risk of disabling, long-lasting/irreversible adverse effects (tendonitis, peripheral neuropathy, CNS effects, aortic aneurysm). Avoid in patients with risk factors for aortic aneurysm.

Paediatric dose

Route: N/A
Frequency: N/A
Max: Not licensed in children/adolescents <18 years (cartilage toxicity risk)
Not recommended in children/adolescents — risk of arthropathy (fluoroquinolone-induced cartilage damage). Specialist indication only.

Dose adjustments

Renal

Significant reduction: eGFR 20–49: 250–500 mg OD. eGFR <20: 250 mg OD (loading 500 mg).

Hepatic

No dose adjustment required (mainly renally excreted)

Clinical pearls

  • MHRA 2019 restriction: use fluoroquinolones only if other antibiotics contraindicated or failed; inform patients of disabling side effect risks
  • Tendon rupture: can occur during treatment AND up to months after stopping — particularly in elderly, on corticosteroids, or transplant patients
  • CNS effects: restlessness, agitation, hallucinations — particularly in elderly; consider QT risk before prescribing in this group
  • Aortic warning: avoid in patients with known aortic aneurysm or family history of aortic disease

Contraindications

  • Previous fluoroquinolone-related tendinopathy
  • QT prolongation or risk factors
  • Epilepsy (relative — lowers seizure threshold)
  • Aortic aneurysm or history of aortic dissection
  • Children <18 years

Side effects

  • Tendinopathy and tendon rupture (Achilles — may occur months after stopping)
  • Peripheral neuropathy (can be permanent)
  • QT prolongation
  • Central effects (headache, dizziness, insomnia, psychosis)
  • Phototoxicity
  • Aortic aneurysm/dissection (MHRA 2019 warning)
  • GI upset

Interactions

  • QT-prolonging drugs — significant additive risk
  • NSAIDs — increased seizure risk
  • Antacids/iron/zinc — reduce absorption (separate by 2h)
  • Warfarin — increased INR (monitor closely)
  • Theophylline — increased theophylline levels

Monitoring

  • Renal function (dose adjustment)
  • Signs of tendinopathy (stop immediately if tendon pain)
  • Neurological symptoms
  • ECG (QTc) if at risk

Reference: BNFc; BNF; MHRA Drug Safety Update 2019; NICE Antimicrobial Prescribing Guidance. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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