Cefadroxil Dosing and Treatment Regimen for Bacterial Infections
For bacterial infections, cefadroxil should be dosed at 1-2 grams per day in adults (either once daily or divided twice daily) and 30 mg/kg/day in children (divided every 12 hours), with specific dosing determined by infection type and severity. 1
Adult Dosing by Infection Type
Urinary Tract Infections
- Uncomplicated lower UTI (cystitis): 1-2 g per day as a single daily dose or divided twice daily 1
- All other UTIs: 2 g per day divided twice daily 1
- Clinical trials demonstrate excellent efficacy with twice-daily dosing compared to four-times-daily cephalexin regimens 2
Skin and Soft Tissue Infections
- Standard dosing: 1 g per day as a single dose or divided twice daily 1
- Comparative studies show 94% satisfactory clinical outcomes with 500 mg twice daily dosing 3
- The twice-daily regimen is as effective as cephalexin 500 mg four times daily, with the advantage of improved compliance 4, 3
Pharyngitis and Tonsillitis
- Group A beta-hemolytic streptococcal infections: 1 g per day as a single dose or divided twice daily for 10 days minimum 1
- The 10-day duration is critical for streptococcal eradication and prevention of rheumatic fever complications 1
Pediatric Dosing
Standard Dosing
- All indications: 30 mg/kg/day divided every 12 hours 1
- Pharyngitis/tonsillitis/impetigo: 30 mg/kg/day as a single daily dose or divided every 12 hours 1
- Clinical studies in children with scarlet fever demonstrate 100% efficacy at 30-49 mg/kg/day, with bacterial eradication occurring within 1-2 days 5
Practical Dosing Chart (from FDA label)
- 10 lbs (4.5 kg): ½ teaspoon of 250 mg/5 mL suspension 1
- 20 lbs (9.1 kg): 1 teaspoon of 250 mg/5 mL suspension 1
- 40 lbs (18.2 kg): 2 teaspoons of 250 mg/5 mL or 1 teaspoon of 500 mg/5 mL 1
- 60 lbs (27.3 kg): 3 teaspoons of 250 mg/5 mL or 1½ teaspoons of 500 mg/5 mL 1
Renal Impairment Adjustments
Initial dose: 1000 mg, then adjust maintenance dosing based on creatinine clearance 1:
- CrCl >50 mL/min: No adjustment needed; dose as normal renal function 1
- CrCl 25-50 mL/min: 500 mg every 12 hours 1
- CrCl 10-25 mL/min: 500 mg every 24 hours 1
- CrCl 0-10 mL/min: 500 mg every 36 hours 1
Key Pharmacokinetic Advantages
- Food does not affect absorption: Can be administered without regard to meals, though giving with food may reduce GI complaints 1, 4
- Longer half-life: Serum half-life of 1.04-1.62 hours allows for once or twice-daily dosing 6
- Superior tissue penetration: Achieves higher and more sustained concentrations in tissues compared to cephalexin and cephradine 4
- Excellent urinary recovery: 75-96% urinary recovery within 6 hours 6
Treatment Duration
- Streptococcal infections: Minimum 10 days to ensure bacterial eradication and prevent complications 1, 5
- UTIs and skin infections: Typically 7-10 days based on clinical response 1, 2
- Reconstituted suspension: Discard after 14 days; must be refrigerated 1
Clinical Efficacy Data
Cefadroxil demonstrates excellent activity against common pathogens 4, 6:
- Staphylococcus aureus and S. epidermidis: Equivalent to cephalexin 6
- Streptococcus pyogenes: 100% eradication in scarlet fever cases within 1-2 days 5
- E. coli, Klebsiella, Proteus mirabilis: Good activity for UTIs 6
- Poor activity: Indole-positive Proteus, Enterobacter, Citrobacter, Serratia, Pseudomonas (MIC >100 mcg/mL) 6
Important Caveats
- Not for surgical prophylaxis: The guideline evidence provided focuses on perioperative prophylaxis with first-generation cephalosporins listing cefadroxil at 500 mg PO every 12 hours, but this is distinct from therapeutic dosing 7
- Compliance advantage: The once or twice-daily dosing significantly improves patient adherence compared to four-times-daily regimens 4, 2
- Palatability in children: Well-tolerated taste profile enhances pediatric compliance 6, 5
- Monitor for reinfection: In streptococcal infections, rare cases of bacterial re-elimination may occur, requiring retreatment 5