What is the recommended cefixime dosage for adults and children, and how should it be adjusted in patients with moderate renal impairment?

Cefixime Dosing

For adults, administer cefixime 400 mg once daily; for children ≥6 months, give 8 mg/kg/day as a single dose or divided every 12 hours; in moderate renal impairment (CrCl 21–59 mL/min), reduce the adult dose to approximately 260 mg daily (13 mL of 100 mg/5 mL suspension or 6.5 mL of 200 mg/5 mL suspension). 1

Adult Dosing (Normal Renal Function)

• The standard adult dose is 400 mg daily, administered as a single 400 mg capsule. 1
• Cefixime may be taken without regard to food, as food does not significantly affect absorption. 1
• For uncomplicated cervical/urethral gonococcal infections, a single oral dose of 400 mg is recommended. 1

Pediatric Dosing (≥6 Months of Age)

• The recommended dose is 8 mg/kg/day of the oral suspension. 1
• This may be given as a single daily dose or divided into 4 mg/kg every 12 hours. 1
• Children weighing >45 kg or >12 years should receive the standard adult dose of 400 mg daily. 1

Important Pediatric Considerations

• Otitis media must be treated with the suspension formulation, not tablets or capsules, because the suspension achieves higher peak blood levels at equivalent doses. 1
• Always specify the concentration when prescribing in milliliters, as cefixime suspension is available in two concentrations: 100 mg/5 mL and 200 mg/5 mL. 1

Renal Impairment Dosing (Adults)

• Normal dosing (400 mg daily) is appropriate for patients with creatinine clearance ≥60 mL/min. 1

Moderate Renal Impairment (CrCl 21–59 mL/min)

• Reduce dose to 13 mL of 100 mg/5 mL suspension (260 mg) or 6.5 mL of 200 mg/5 mL suspension (260 mg) once daily. 1
• The 200 mg/5 mL concentration is preferred for patients with renal dysfunction. 1
• This dosing also applies to patients on hemodialysis. 1

Severe Renal Impairment (CrCl ≤20 mL/min)

• Reduce dose to 8.6 mL of 100 mg/5 mL suspension (172 mg) or 4.4 mL of 200 mg/5 mL suspension (176 mg) once daily. 1
• This dosing also applies to patients on continuous peritoneal dialysis. 1

Key Renal Dosing Principles

• Neither hemodialysis nor peritoneal dialysis removes significant amounts of cefixime from the body, so supplemental post-dialysis doses are not needed. 1, 2
• The elimination half-life increases from approximately 3–4 hours in normal renal function to 12–14 hours in patients with CrCl <20 mL/min. 3, 2
• Pharmacokinetic alterations become statistically significant when creatinine clearance falls below 20 mL/min. 2

Duration of Therapy

• For infections caused by Streptococcus pyogenes, administer cefixime for at least 10 days to prevent complications such as acute rheumatic fever. 1
• For most other indications, a median therapy duration of 6 days has demonstrated high efficacy (98.7% cure/improvement in adults, 98.0% in children). 4

Clinical Efficacy Evidence

• Large post-marketing surveillance (9,568 patients) demonstrated cure or improvement in 98.7% of adults and 98.0% of children with respiratory tract infections. 4
• Multinational studies confirm excellent microbiological eradication, including 100% of Streptococcus pneumoniae isolates from children and 89% of isolates from adults with respiratory infections. 5
• Adverse events occur in only 1.12% of adults and 1.92% of children, with 96.7% of children accepting the dry syrup formulation very well or well. 4

Common Pitfalls to Avoid

• Do not substitute tablets/capsules for suspension when treating otitis media in children, as bioavailability differs significantly. 1
• Always verify suspension concentration (100 mg/5 mL vs. 200 mg/5 mL) when prescribing volume-based doses to prevent dosing errors. 1
• Do not use normal doses in patients with CrCl <60 mL/min without appropriate dose reduction, as drug accumulation occurs. 1, 3
• Reconstituted suspension remains stable for only 14 days at room temperature or refrigerated; discard unused portions after this period. 1