Cefaclor Suspension Dosing
For pediatric patients, cefaclor suspension should be dosed at 20 mg/kg/day divided every 8 hours (three times daily) for most infections, or 40 mg/kg/day divided every 8 hours for more serious infections including otitis media, with a maximum daily dose of 1 gram. 1
Standard Dosing Regimen
The FDA-approved dosing from the drug label provides the authoritative framework 1:
Pediatric Dosing (Every 8 Hours)
Mild to moderate infections: 20 mg/kg/day divided into three doses (every 8 hours)
- Example: 9 kg child = 1/2 teaspoon (125 mg/5 mL) three times daily
- Example: 18 kg child = 1 teaspoon (125 mg/5 mL) three times daily
More serious infections, otitis media, or less susceptible organisms: 40 mg/kg/day divided into three doses (every 8 hours), maximum 1 g/day
- Example: 9 kg child = 1 teaspoon (125 mg/5 mL) three times daily
- Example: 18 kg child = 1 teaspoon (250 mg/5 mL) three times daily
Alternative Twice-Daily Dosing
For otitis media and pharyngitis specifically, the total daily dose may be divided and given every 12 hours (twice daily) 1. This improves compliance while maintaining efficacy:
- Pharyngitis (20 mg/kg/day): 18 kg child = 1/2 teaspoon (375 mg/5 mL) twice daily
- Otitis media (40 mg/kg/day): 9 kg child = 1/2 teaspoon twice daily; 18 kg child = 1 teaspoon twice daily
Adult Dosing
- Standard: 250 mg every 8 hours
- Severe infections or less susceptible organisms: 500 mg every 8 hours 1
Duration of Therapy
- Streptococcal infections: Minimum 10 days 1
- Otitis media: 10 days 2, 3
- Most other infections: Continue for 3-5 days after signs of infection disappear 4
Important Clinical Considerations
Limitations of Cefaclor
A critical caveat: Cefaclor has poor activity against H. influenzae, fair activity against penicillin-susceptible pneumococci, and no activity against drug-resistant S. pneumoniae (DRSP), resulting in poor overall efficacy against bacterial respiratory tract pathogens 5. This significantly limits its utility as a first-line agent for respiratory infections despite FDA approval for these indications.
Practical Administration
- Administer with or without food (food delays but does not reduce absorption) 6
- Suspension remains stable after reconstitution per label instructions 1
- The suspension formulation is generally well-tolerated in children 7
Renal Impairment
Dosage adjustment is typically not required in renal impairment, though cefaclor is primarily renally eliminated 1, 6
Clinical Efficacy Data
Research supports the labeled dosing, with studies showing 93-97% bacteriologic cure rates at 40 mg/kg/day for otitis media 3, though one study suggested mild preference for alternative agents like trimethoprim-sulfamethoxazole due to twice-daily dosing and lower cost 2.