What is the recommended dose of cefixime (Cefixime) for a patient with a urinary tract infection (UTI) and severe impaired renal function, indicated by a glomerular filtration rate (GFR) of 26?

Cefixime Dosing for UTI with GFR 26 mL/min

For a patient with GFR 26 mL/min and UTI, reduce the standard cefixime dose to 200 mg once daily (half the normal 400 mg daily dose), as this level of renal impairment significantly prolongs drug elimination and requires dose adjustment. 1, 2

Rationale for Dose Reduction

Severe renal impairment (GFR <30 mL/min) dramatically alters cefixime pharmacokinetics:

• The elimination half-life extends from 3-4 hours in normal renal function to approximately 11 hours when creatinine clearance falls below 30 mL/min 1
• Serum concentrations remain elevated for prolonged periods—in patients with GFR 10-30 mL/min, measurable drug levels persist at 24 hours (0.99 mcg/mL) compared to near-complete clearance in those with better renal function 1
• Only 40% of cefixime is renally cleared (60% hepatic), but this renal component becomes critically important when kidney function is severely impaired 2

Specific Dosing Recommendation

Administer 200 mg orally once daily, divided into 100 mg twice daily if gastrointestinal tolerance is poor:

• The standard dose of 400 mg/day should be reduced to 200 mg/day when creatinine clearance is less than 20 mL/min 2
• Your patient's GFR of 26 mL/min falls into the "severely impaired" category (GFR 10-30 mL/min) where dose reduction is mandatory 1
• Consider splitting the dose to 100 mg twice daily rather than 200 mg once daily, as the once-daily regimen shows higher incidence of gastrointestinal adverse effects 3

Clinical Considerations

Monitor for therapeutic response and adjust based on clinical improvement:

• Urinary concentrations remain adequate even with dose reduction—peak urinary levels occur at 4-6 hours and remain elevated through 24 hours in patients with severe renal impairment 1
• Approximately 20% of cefixime is excreted as active drug in urine, providing sufficient concentrations for UTI treatment even at reduced doses 3
• The drug is not significantly removed by hemodialysis or peritoneal dialysis, so no supplemental dosing is needed post-dialysis 2

Important Caveats

Obtain urine culture before initiating therapy, but do not delay treatment:

• Cefixime has excellent activity against common uropathogens (E. coli, Klebsiella) in uncomplicated UTI 3
• For complicated UTI, sensitivity testing is essential as gram-positive organisms and non-fermenting bacteria resistant to cefixime may be present 3
• If the patient has pyelonephritis or appears systemically ill, consider parenteral therapy initially (such as ceftriaxone 1-2 g once daily) before transitioning to oral cefixime 4

The general guideline for antimicrobials in severe renal impairment (GFR <30 mL/min) emphasizes dose reduction or interval extension to prevent drug accumulation and toxicity 5, which directly applies to cefixime dosing in your patient.