Does cefixime (cephalosporin antibiotic) require renal adjustment in patients with impaired renal function?

Cefixime Dosage Adjustment in Renal Impairment

Cefixime requires dosage adjustment only in patients with severe renal impairment (creatinine clearance less than 20 mL/min). 1

Dosing Recommendations Based on Renal Function

• For patients with creatinine clearance ≥60 mL/min: Normal dose and schedule (400 mg daily for adults) can be maintained 1
• For patients with creatinine clearance 21-59 mL/min: Normal dose can be maintained 1
• For patients with creatinine clearance ≤20 mL/min or those on continuous peritoneal dialysis: Reduce dosing frequency but maintain dose strength to preserve antimicrobial efficacy 1, 2

Pharmacokinetic Changes in Renal Impairment

• Cefixime is cleared partly by the liver (60%) and partly by the kidneys (40%) 3
• In patients with severe renal impairment (creatinine clearance <20 mL/min):
  • Elimination half-life increases from 3-4 hours to 12-14 hours 4, 2
  • Apparent total body clearance and renal clearance decrease proportionally to the degree of renal impairment 4
  • Peak serum concentrations (Cmax) and time to peak concentration (Tmax) are slightly increased 4

Specific Recommendations for Dialysis Patients

• Neither hemodialysis nor peritoneal dialysis removes significant amounts of cefixime from the body 1, 3, 2
• For patients on hemodialysis: No supplemental doses are necessary after dialysis sessions 2
• For patients on continuous ambulatory peritoneal dialysis (CAPD): CAPD removes only about 1.57% of cefixime body burden over 72 hours 2

Clinical Considerations and Monitoring

• Beta-lactam antibiotics, including cephalosporins, can cause neurotoxicity, particularly in patients with renal impairment 5
• While cefixime has lower pro-convulsive activity compared to some other cephalosporins, monitoring for neurological symptoms is still important in patients with renal dysfunction 5
• Signs of potential neurotoxicity include confusion, encephalopathy, myoclonus, seizures, and status epilepticus 5, 6
• Even with appropriate renal dose adjustments, neurological adverse effects can still occur with cephalosporins 6

Practical Approach to Cefixime Dosing in Renal Impairment

• Assess creatinine clearance before initiating therapy 1
• For severe renal impairment (CrCl ≤20 mL/min), use the FDA-recommended adjusted dosing 1
• Monitor renal function during therapy, especially in patients with fluctuating renal function 4
• Be vigilant for signs of neurotoxicity, particularly in patients with severe renal impairment 5, 6

Remember that while cefixime requires less aggressive dose adjustment compared to some other cephalosporins, appropriate dosing based on renal function is still essential to minimize toxicity while maintaining antimicrobial efficacy.