What is the recommended dosage of Cefixime (Cefixime) for treating Urinary Tract Infections (UTI)?

Cefixime Dosage for Urinary Tract Infections

For uncomplicated urinary tract infections (UTIs), the recommended dosage of cefixime is 400 mg daily, which can be given as a single daily dose or divided into 200 mg twice daily. 1

Adult Dosing

• The FDA-approved dosage for adults with uncomplicated UTIs is 400 mg daily, which may be given as a 400 mg capsule once daily 1
• For patients with normal renal function (creatinine clearance ≥60 mL/min), the standard 400 mg daily dose is appropriate 1
• Twice daily dosing (200 mg twice daily) may be better tolerated with fewer gastrointestinal side effects than the once-daily 400 mg regimen 2

Renal Dosage Adjustments

• For patients with renal impairment, dosage adjustment is required 1:
  • Creatinine clearance 21-59 mL/min: Reduce to 65% of normal dose (approximately 260 mg daily)
  • Creatinine clearance ≤20 mL/min or on hemodialysis/peritoneal dialysis: Reduce to 43% of normal dose (approximately 172 mg daily)

Pediatric Dosing

• For pediatric patients 6 months or older, the recommended dose is 8 mg/kg/day of the suspension 1
• This can be administered as a single daily dose or divided into two doses of 4 mg/kg every 12 hours 1
• Children weighing more than 45 kg or older than 12 years should receive the adult dose of 400 mg daily 1

Duration of Therapy

• While the FDA label doesn't specify the exact duration for UTI treatment, clinical studies have typically used 7-10 days of therapy 3, 4
• For complicated UTIs, treatment duration is generally 7-14 days 5

Clinical Efficacy

• Clinical studies have demonstrated high efficacy rates for cefixime in uncomplicated UTIs:
  • 98% overall clinical effectiveness rate in acute uncomplicated cystitis 3
  • 94-96% clinical cure rate for lower UTIs 6
  • Bacteriological cure rates of 89-97.5% for UTIs 6

Important Considerations

• Cefixime is indicated for UTIs caused by susceptible isolates of Escherichia coli and Proteus mirabilis 1
• Obtain a urine culture before starting antibiotics to guide targeted therapy if empiric treatment fails 7
• Cefixime has little activity against Staphylococcus aureus and is inactive against Pseudomonas aeruginosa 4
• Approximately 20% of cefixime is excreted by the kidneys as active drug, making it suitable for UTI treatment 8

Common Side Effects

• The most common adverse effects are gastrointestinal disturbances, particularly diarrhea and stool changes 4
• These side effects are usually mild to moderate, transient, and occur primarily in the first few days of treatment 4
• The once-daily 400 mg dose shows a higher incidence of gastrointestinal adverse effects than the twice-daily 200 mg regimen 8

Pitfalls and Caveats

• Cefixime should only be used for infections that are proven or strongly suspected to be caused by susceptible bacteria to reduce the development of drug-resistant bacteria 1
• When culture and susceptibility information are available, they should be considered in selecting or modifying antimicrobial therapy 1
• If symptoms persist after 72 hours of treatment, reevaluate the diagnosis and consider imaging to rule out complications 7