Can norfloxacin (Norflox) be given in acute kidney injury (AKI)?

Norfloxacin Use in Acute Kidney Injury

Norfloxacin should be avoided in patients with acute kidney injury (AKI) unless no suitable, less nephrotoxic alternatives are available, and if used, requires dose adjustment based on the severity of kidney dysfunction. 1

Risk Assessment and Decision Making

• Fluoroquinolones like norfloxacin require dose reduction of 50% when the glomerular filtration rate (GFR) falls below 15 ml/min/1.73 m² 2
• Norfloxacin is primarily eliminated by the kidneys, with serum half-life increasing from 3.87 hours in normal renal function to 8.34 hours in severe renal impairment (creatinine clearance <20 ml/min) 3
• Patients with AKI are at higher risk for drug toxicity due to impaired drug clearance and altered drug metabolism 1

Recommendations for Norfloxacin Use in AKI

When to Avoid Norfloxacin in AKI:

• When a suitable and less nephrotoxic alternative is available 1
• When the patient already has risk factors for kidney injury (advanced age, previous AKI, diabetes, hypertension) 1
• When the patient is already receiving other nephrotoxic drugs due to risk of pharmacokinetic or pharmacodynamic interactions 1
• When appropriate monitoring of renal function and drug levels cannot be ensured 1

If Norfloxacin Must Be Used in AKI:

• Dosage adjustment is necessary in patients with creatinine clearance less than 20 ml/min 3
• Regular monitoring of renal function is essential while on norfloxacin therapy 1
• The duration of norfloxacin exposure should be minimized when possible 1
• Consider that urinary concentrations will be lower with dose reduction, potentially affecting efficacy for urinary tract infections 3

Important Considerations

• AKI can significantly alter drug metabolism through:

  • Changes in hepatic blood flow 1
  • Effects on cytochrome P450 activity 1
  • Alterations in protein binding affecting drug distribution 1
  • Changes in drug transporters 1

• Fluoroquinolones, including newer agents like moxifloxacin, have been reported to cause acute interstitial nephritis, which can worsen existing AKI 4

• In many cases of AKI on admission, renal function improves within 48 hours, suggesting that immediate dose reduction of antibiotics with wide therapeutic indices might not always be necessary 5

Monitoring and Follow-up

• Monitor serum creatinine regularly during norfloxacin therapy in patients with AKI 1
• Assess for signs of drug toxicity, which may be more likely with impaired renal clearance 1
• Consider therapeutic drug monitoring if available, as high trough levels are associated with increased nephrotoxicity 6
• Re-evaluate dosing as renal function changes, especially if AKI resolves 1, 5