How this instrument works
Cefdinir is an oral cephalosporin antibiotic commonly prescribed in children for acute otitis media, sinusitis, pharyngitis/tonsillitis, and skin or skin-structure infections. Like many pediatric antibiotics, its dose scales with body weight rather than using one fixed adult dose for every patient.
The FDA label sets out three pediatric regimens this calculator implements. For otitis media, sinusitis, and pharyngitis/tonsillitis, cefdinir can be given either as 7 mg/kg every 12 hours or as 14 mg/kg once daily — the label treats these as interchangeable options for those indications. For skin and skin-structure infections, only the twice-daily 7 mg/kg regimen is labeled; once-daily dosing has not been studied for that indication, so it isn't an option for skin infections even though it's approved for the other three.
Regardless of the weight-based calculation, the FDA label caps the total daily dose at 600 mg, mirroring the standard adult dose. For larger children, the raw weight × rate × frequency calculation can exceed that ceiling — in which case the capped 600 mg/day figure, not the higher weight-based number, is the labeled maximum, and the per-dose amount is recalculated from the capped total.
- Enter the child's weight in kilograms.
- Select the regimen: AOM/sinusitis/pharyngitis twice daily (7 mg/kg), AOM/sinusitis/pharyngitis once daily (14 mg/kg), or skin/skin-structure infection — twice daily only (7 mg/kg).
- Read the rate per administration, doses per day, the uncapped weight-based daily dose, the daily dose after the 600 mg/day cap is applied, and the resulting amount per dose.
Worked example — a 20 kg child, and when the 600 mg cap applies
A 20 kg child with otitis media on the standard twice-daily regimen: 20 kg × 7 mg/kg = 140 mg per dose, given twice a day, for a total of 280 mg/day — comfortably under the 600 mg/day cap, so the cap has no effect here.
The same 20 kg child on the once-daily alternative for the same indication: 20 kg × 14 mg/kg = 280 mg, given as a single daily dose — the same 280 mg/day total, delivered in one dose instead of two.
A larger 50 kg child on the twice-daily regimen: the uncapped calculation is 50 kg × 7 mg/kg × 2 = 700 mg/day, which exceeds the 600 mg/day FDA label maximum. The actual dose is therefore capped at 600 mg/day — 300 mg per dose — not the higher weight-based figure.
Questions
What's the difference between the twice-daily and once-daily cefdinir regimens?
For otitis media, sinusitis, and pharyngitis/tonsillitis, the FDA label allows either 7 mg/kg every 12 hours or 14 mg/kg once daily — both deliver the same total daily amount, just split into a different number of doses. The label treats the two schedules as interchangeable options for those specific indications.
Can once-daily dosing be used for a skin infection?
No. The FDA label restricts skin and skin-structure infections to the twice-daily (7 mg/kg every 12 hours) regimen — once-daily dosing has not been studied for that indication. This calculator's once-daily rate only applies to the otitis media/sinusitis/pharyngitis regimen.
Why is there a 600 mg/day cap?
The FDA label sets a flat 600 mg/day maximum total dose regardless of the weight-based calculation, matching the standard adult dose. For larger children, the weight-based arithmetic can exceed this ceiling — in that case the capped 600 mg/day figure is the labeled maximum, not the higher weight-based number.
Does this calculator use weight in pounds or kilograms?
Kilograms — that's the unit the FDA label's mg/kg dosing is written in. Convert pounds to kilograms first (divide pounds by about 2.2) if that's what you have on hand.
Is cefdinir dosed the same way in adults?
No. Adults and adolescents are typically given a fixed dose rather than weight-based mg/kg dosing, with the specific regimen depending on the infection being treated. This calculator implements the pediatric weight-based schedule, not adult fixed dosing.
Who should use this calculator?
Clinicians, pharmacists, and caregivers checking a prescribed pediatric cefdinir dose against the FDA label's weight-based schedule. It is not a substitute for the prescribing decision itself, which also depends on the specific infection, allergy history, kidney function, and other individualized factors.
Does this account for reduced dosing in kidney impairment?
No. The FDA label recommends a reduced dose for patients with significant renal insufficiency (creatinine clearance under 30 mL/min). This calculator only applies the standard weight-based schedule for patients with normal kidney function and does not adjust for renal impairment.
References
Read this first: This instrument computes a screening figure from population formulas — it is not a diagnosis, and it cannot see the whole picture a clinician can. Use it to inform a conversation, not to replace one.