What is the recommended dosage of cefadroxil (a first-generation cephalosporin) for an adult patient with a urinary tract infection (UTI)?

Cefadroxil Dosage for UTI

For uncomplicated lower urinary tract infections (cystitis) in adults, cefadroxil should be dosed at 1-2 grams per day, given either as a single daily dose or divided into twice-daily dosing. 1

Adult Dosing by UTI Type

Uncomplicated Cystitis

• Standard dose: 1-2 grams daily, administered either once daily or divided into twice-daily doses 1
• This represents the FDA-approved dosing for uncomplicated lower urinary tract infections 1

All Other UTIs (Including Complicated UTIs)

• Dose: 2 grams daily in divided doses (twice daily) 1
• This higher dose is necessary because all male UTIs and complicated UTIs require more aggressive treatment 2

Treatment Duration Considerations

• Uncomplicated cystitis in women: 3 days is the typical duration recommended by European guidelines for first-generation cephalosporins like cefadroxil 3
• Complicated UTIs or male patients: 7-14 days of treatment is required, as these infections are more difficult to eradicate 2, 4
• The longer duration for males reflects that all male UTIs are considered complicated regardless of other factors 2

Pediatric Dosing

• 30 mg/kg/day divided every 12 hours for urinary tract infections in children 1
• Maximum daily dose should not exceed adult dosing 1

Renal Dose Adjustments

For patients with impaired renal function, dosing must be adjusted to prevent drug accumulation 1:

• Initial dose: 1000 mg for all patients with renal impairment 1
• Maintenance dosing based on creatinine clearance:
  • CrCl >50 mL/min: Normal dosing interval 1
  • CrCl 25-50 mL/min: 500 mg every 12 hours 1
  • CrCl 10-25 mL/min: 500 mg every 24 hours 1
  • CrCl <10 mL/min: 500 mg every 36 hours 1

Important Clinical Considerations

When to Use Cefadroxil

• Cefadroxil is listed as an alternative agent for uncomplicated cystitis in women, appropriate when local E. coli resistance to cephalosporins is <20% 3
• First-generation cephalosporins like cefadroxil are not first-line agents but serve as reasonable alternatives when first-line options (fosfomycin, nitrofurantoin, pivmecillinam) are unavailable or contraindicated 3

Critical Pitfalls to Avoid

• Do not use cefadroxil for suspected pyelonephritis or systemic infections without ensuring adequate serum concentrations, as it is primarily renally excreted 3
• Do not treat male UTIs for less than 7 days, as shorter courses lead to treatment failure 2, 4
• Always obtain urine culture before starting therapy in complicated UTIs to guide definitive treatment 2, 4
• Do not use empirically if local resistance exceeds 20% for E. coli 3

Administration Tips

• Can be administered without regard to meals, though taking with food may reduce gastrointestinal side effects 1
• The twice-daily dosing strategy improves patient adherence compared to more frequent dosing 5