π§ͺ Cefdinir Dosage Reference
FDA-label weight-based dosing. Informational only, pharmacist verifies.
INFORMATIONAL ONLY. Never dose medication from a webpage. The prescriber and pharmacist determine the dose.
Cefdinir (Omnicef) is a third-generation cephalosporin commonly prescribed for children's ear infections, sinusitis, and strep throat. The FDA label doses it by weight: 14 mg/kg once daily or 7 mg/kg twice daily, up to 600 mg a day. This page shows what those regimens work out to for a given weight, including suspension volumes. It is a reference for understanding the prescription, not for writing one: the prescriber and pharmacist own the dose.
How to Use This Reference
Enter the child's weight and pick the regimen to see the per-dose milligrams and suspension milliliters.
Enter weight in kilograms. If you only know pounds, divide by 2.2.
Choose once-daily (14 mg/kg) or twice-daily (7 mg/kg) dosing, matching the prescription.
Read the per-dose mg and the mL for each suspension strength. Compare with the pharmacy label; they should match.
The FDA-Label Regimens
Both regimens deliver the same total daily milligrams; studies showed once-daily dosing works as well for the labeled indications, which helps adherence enormously with children. The 600 mg ceiling matters for bigger kids: a 50 kg child at 14 mg/kg would compute 700 mg, but the label caps at 600. Duration depends on indication: 5 days often suffices for strep pharyngitis in some protocols, 10 for otitis media, and the prescriber sets it.
Cefdinir is notable for two quirks parents ask about. Reddish stools: cefdinir can turn stools red, especially with iron-containing foods or vitamins, and it is harmless but alarming if unexpected. And it is a cephalosporin, so true penicillin allergy needs clinician judgment about cross-reactivity. Neither quirk changes the dose, but both change the phone calls to the pediatrician.
Worked Example
A 20 kg child (about 44 lb), once-daily regimen: 14 x 20 = 280 mg once daily. With the 125 mg/5 mL suspension: 280/125 x 5 = 11.2 mL. With the 250 mg/5 mL suspension: 280/250 x 5 = 5.6 mL. Twice-daily regimen: 7 x 20 = 140 mg per dose, twice daily, totaling the same 280 mg/day. A 45 kg child once-daily: 14 x 45 = 630 mg, capped to 600 mg. Check the pharmacy label against these numbers; if they differ, call the pharmacist before the first dose, because label errors, while rare, are the exact thing double-checking catches.
Administration Tips That Matter
Shake the suspension well before every dose; the drug settles. Use the oral syringe from the pharmacy, not a kitchen spoon: a "teaspoon" from the drawer can be anywhere from 3 to 7 mL. Cefdinir can be taken with or without food, but antacids and iron supplements should be spaced a couple of hours apart because they reduce absorption. Finish the full course even when the child feels better after day three: stopping early is how resistant bacteria get selected. Store the reconstituted suspension at room temperature and discard after the days-supply on the label, usually 10 days.
Call the prescriber for rash, hives, trouble breathing, severe diarrhea, or no improvement in 48 to 72 hours. Mild loose stools are common with antibiotics; bloody or watery diarrhea is not. And keep the perspective: most childhood ear infections and colds are viral and do not need antibiotics at all, which is why watchful waiting is sometimes the prescription. When antibiotics are warranted, the right dose from the label, verified by the pharmacist, is the safe path.
Why Weight-Based Dosing Exists
Children are not small adults for drug dosing: a fixed adult tablet would overdose a toddler and underdose a teen. Weight-based mg/kg dosing scales the drug to body size so exposure stays in the effective-and-safe window across ages. It is also why an accurate current weight matters: weigh the child rather than guessing, especially for repeat prescriptions months apart. For general weight-based dose math, our dosage calculator covers the method, and our IV drip rate calculator covers infusions. But for cefdinir specifically, the prescriber's label is the final authority.
For informational purposes only, not medical advice. Consult a healthcare professional.
Frequently Asked Questions
What is the cefdinir dosage for children?
Per the FDA label: 14 mg/kg once daily or 7 mg/kg twice daily, up to 600 mg per day, for otitis media, sinusitis, and pharyngitis. A 20 kg child gets 280 mg once daily. The prescriber sets the regimen and duration; this page is for reference only.
How many mL of cefdinir suspension per dose?
It depends on weight and suspension strength. Example: a 20 kg child on once-daily dosing needs 280 mg, which is 11.2 mL of the 125 mg/5 mL suspension or 5.6 mL of the 250 mg/5 mL suspension. Always follow the pharmacy label.
Can cefdinir be given once a day?
Yes. The FDA label includes 14 mg/kg once daily as equivalent to 7 mg/kg twice daily for the labeled indications. Once-daily dosing improves adherence. Follow whichever regimen the prescription specifies.
Why are my child's stools red on cefdinir?
Cefdinir can cause reddish stools, especially when taken with iron-containing foods, formula, or vitamins: the drug forms a complex with iron. It is harmless and resolves after the course. Report bloody stools that look different from this known effect.
How long does a cefdinir prescription last?
Typically 5-10 days depending on indication: often 10 days for otitis media, 5-10 for sinusitis and pharyngitis per the prescriber. Finish the full course even if symptoms resolve early.
Should cefdinir be taken with food?
It can be taken with or without food. Space antacids and iron supplements about 2 hours apart, as they reduce cefdinir absorption. Shake the suspension well before each dose.
What if I miss a dose of cefdinir?
Give it when remembered unless it is almost time for the next dose; then skip and resume the schedule. Do not double up. If doses are repeatedly missed, call the prescriber for guidance.
Is cefdinir safe with penicillin allergy?
It needs clinician judgment. Cefdinir is a cephalosporin, a related antibiotic class, and cross-reactivity is possible though uncommon. Anyone with a true penicillin allergy should have the prescriber and pharmacist aware before starting.
What is the maximum cefdinir dose?
600 mg per day total, for children and adults. Larger children whose weight-based calculation exceeds 600 mg get capped at 600 mg. The pharmacist verifies this on every prescription.
When should I call the doctor during cefdinir treatment?
For rash, hives, breathing difficulty, severe or bloody diarrhea, or no improvement within 48-72 hours. Mild loose stools are common; severe watery diarrhea needs prompt evaluation.