Cefdinir Dosing Recommendations
Adult Dosing
For adults with normal renal function, cefdinir is dosed at 300 mg twice daily or 600 mg once daily, depending on the infection type and severity. 1
Standard Adult Regimens by Indication
Community-acquired pneumonia and acute bacterial exacerbations of chronic bronchitis: 300 mg twice daily for 10 days provides adequate coverage against common respiratory pathogens including Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. 2, 3
Acute maxillary sinusitis and pharyngitis/tonsillitis: Either 300 mg twice daily for 10 days or 600 mg once daily for 10 days are equally effective options. 3, 4
Uncomplicated skin and skin structure infections: 300 mg twice daily for 10 days is the recommended regimen. 1, 3
Important Considerations for Adults
Cefdinir may be taken without regard to meals, though administration with food reduces bioavailability by 10-16% for capsules and 33-44% for suspension—a reduction that is not clinically significant. 1
The drug achieves therapeutic concentrations in respiratory tissues (tonsil, sinus, lung) and skin blister fluid, supporting its efficacy in these infections. 1
Pediatric Dosing (Age 6 Months Through 12 Years)
The total daily pediatric dose is 14 mg/kg, up to a maximum of 600 mg per day, administered either as 7 mg/kg every 12 hours or 14 mg/kg once daily. 1
Pediatric Dosing by Indication
| Infection Type | Dosing Regimen | Duration |
|---|---|---|
| Acute bacterial otitis media | 7 mg/kg q12h or 14 mg/kg q24h | 5–10 days (10 days for once-daily) |
| Acute maxillary sinusitis | 7 mg/kg q12h or 14 mg/kg q24h | 10 days |
| Pharyngitis/tonsillitis | 7 mg/kg q12h or 14 mg/kg q24h | 5–10 days (10 days for once-daily) |
| Uncomplicated skin infections | 7 mg/kg q12h only | 10 days |
Weight-Based Dosing Chart (Oral Suspension)
For children weighing ≥43 kg, use the maximum adult dose of 600 mg per day. 1
| Weight | 125 mg/5 mL Suspension | 250 mg/5 mL Suspension |
|---|---|---|
| 9 kg (20 lbs) | 2.5 mL q12h or 5 mL q24h | Use 125 mg/5 mL product |
| 18 kg (40 lbs) | 5 mL q12h or 10 mL q24h | 2.5 mL q12h or 5 mL q24h |
| 27 kg (60 lbs) | 7.5 mL q12h or 15 mL q24h | 3.75 mL q12h or 7.5 mL q24h |
| 36 kg (80 lbs) | 10 mL q12h or 20 mL q24h | 5 mL q12h or 10 mL q24h |
| ≥43 kg (95 lbs) | 12 mL q12h or 24 mL q24h | 6 mL q12h or 12 mL q24h |
Critical Pediatric Considerations
Once-daily dosing has not been studied for skin infections; therefore, twice-daily administration (7 mg/kg q12h) must be used for uncomplicated skin and skin structure infections. 1
Cefdinir suspension may be administered without regard to meals in pediatric patients, as safety and efficacy studies were conducted irrespective of food intake. 1
The suspension remains stable for 10 days after reconstitution when stored at room temperature (25°C/77°F); discard any unused portion after this period. 1
Renal Impairment Dosing Adjustments
Adults with Renal Insufficiency
For adults with creatinine clearance <30 mL/min, reduce the dose to 300 mg once daily. 1
In patients with CLcr 30–60 mL/min, cefdinir Cmax and half-life increase approximately 2-fold, and AUC increases approximately 3-fold. 1
In patients with CLcr <30 mL/min, Cmax increases approximately 2-fold, half-life increases approximately 5-fold, and AUC increases approximately 6-fold. 1
Estimating Creatinine Clearance in Adults
Use the Cockcroft-Gault equation (serum creatinine must reflect steady-state renal function): 1
- Males: CLcr = [(weight in kg) × (140 – age)] / [(72) × (serum creatinine in mg/dL)]
- Females: CLcr = 0.85 × above value
Pediatric Patients with Renal Insufficiency
For pediatric patients with creatinine clearance <30 mL/min/1.73 m², reduce the dose to 7 mg/kg (up to 300 mg) once daily. 1
Estimating Creatinine Clearance in Pediatric Patients
Use the Schwartz equation: 1
- CLcr = (K × body length or height in cm) / (serum creatinine in mg/dL)
- Where K = 0.55 for children >1 year and 0.45 for infants ≤1 year
Hemodialysis Patients
For patients on chronic hemodialysis, administer 300 mg (or 7 mg/kg in pediatric patients) every other day, with an additional dose of 300 mg (or 7 mg/kg) at the conclusion of each hemodialysis session. 1
Hemodialysis removes approximately 63% of cefdinir from the body and reduces the elimination half-life from 16 hours to 3.2 hours. 1
The fractional removal by hemodialysis is 61%, necessitating supplemental dosing after each dialysis session. 5
Common Pitfalls and Caveats
Urinary Tract Infections
Cefdinir should be avoided for the treatment of urinary tract infections due to its low bioavailability (16-25%) and poor urinary penetration. 6
A recent study demonstrated that cefdinir was independently associated with treatment failure (odds ratio 1.9) compared to cephalexin for uncomplicated UTIs, with nearly twice the failure rate (23.4% vs 12.5%). 6
Patients who failed cefdinir therapy had higher rates of cefazolin-nonsusceptible (37.5% vs 0%) and ceftriaxone-nonsusceptible (31.2% vs 0%) pathogens on repeat culture. 6
Spectrum Limitations
Cefdinir is inactive against Enterobacter spp., Pseudomonas spp., Enterococcus spp., penicillin-resistant streptococci, and methicillin-resistant staphylococci. 1
β-lactamase negative, ampicillin-resistant (BLNAR) H. influenzae strains are typically non-susceptible to cefdinir. 1
Dosing Errors to Avoid
Do not use once-daily dosing for skin infections in pediatric patients; twice-daily administration is required. 1
Do not exceed the maximum daily dose of 600 mg in pediatric patients, even if weight-based calculations suggest higher doses. 1
Do not forget to adjust doses in renal impairment; failure to do so results in significantly elevated drug concentrations and prolonged half-life. 1