Cefixime Dosing for UTI
For uncomplicated urinary tract infections in adults, cefixime should be administered at 400 mg daily as a single dose or divided into two 200 mg doses. 1
Adult Dosing
- Standard adult dose: 400 mg daily 1
- Can be given as a single 400 mg dose or divided as 200 mg twice daily
- May be administered without regard to food
- Single daily dosing may be associated with more gastrointestinal side effects than twice daily dosing 2
Pediatric Dosing (6 months or older)
- Recommended dose: 8 mg/kg/day 1
- May be administered as a single daily dose or divided into two doses (4 mg/kg every 12 hours)
- Children weighing more than 45 kg or older than 12 years should receive the adult dose
Dosing in Renal Impairment
Dose adjustments are required based on creatinine clearance: 1
- CrCl ≥60 mL/min: Normal dose (400 mg daily)
- CrCl 21-59 mL/min: 65% of normal dose
- CrCl ≤20 mL/min or on dialysis: 43% of normal dose
Treatment Duration
- For uncomplicated UTIs, a 7-day course is typically sufficient 3
- For infections due to Streptococcus pyogenes, treatment should continue for at least 10 days 1
Clinical Efficacy
Cefixime has demonstrated high efficacy rates in the treatment of UTIs:
- 98% effectiveness rate in uncomplicated cystitis 4
- 57% effectiveness rate in complicated UTIs 4
- Comparable efficacy to co-trimoxazole and amoxicillin in acute uncomplicated UTI 5
Important Considerations
- Cefixime is indicated for UTIs caused by susceptible isolates of Escherichia coli and Proteus mirabilis 1
- For complicated UTIs, sensitivity testing should be performed before initiating treatment, as gram-positive and non-fermenting pathogens may be resistant to cefixime 2
- In uncomplicated UTIs, therapy can often be initiated prior to sensitivity results due to cefixime's broad spectrum against common uropathogens 2
Common Adverse Effects
- Diarrhea and stool changes (usually mild to moderate and transient) 5
- Gastrointestinal discomfort
- Potential for abnormal liver function tests 4
Pitfalls to Avoid
- Do not use cefixime for UTIs caused by Pseudomonas aeruginosa as it has no activity against this organism 5
- Do not treat asymptomatic bacteriuria as it promotes resistance without clinical benefit 3
- Do not perform surveillance urine cultures in asymptomatic patients 3
- Avoid unnecessarily prolonged treatment durations (>7 days) for uncomplicated UTIs as this increases the risk of adverse effects and antimicrobial resistance 3
By following these dosing recommendations and considerations, cefixime can be effectively used for the treatment of susceptible urinary tract infections while minimizing the risk of treatment failure and antimicrobial resistance.