Cefaclor pediatric dose calculator
Use this Cefaclor pediatric dose calculator to match the prescribed child dose to the exact liquid, tablet, or capsule strength before you give it.
Usual oral dose for children 1 month and older: 20 mg/kg per day split every 8 hours, or 40 mg/kg per day for ear infections and more serious infections (max 1 g per day). Ear and throat infections may be split every 12 hours. Enter weight for the mL on your bottle; give the dose your child's prescriber ordered.
dose calculator basics
Cefaclor pediatric dose calculator details
Use this Cefaclor calculator as the fast parent page for weight-based dose checks, mL conversion, common strengths, and the practical safety steps that generic calculator sites often skip.
Formula
mL per dose = (child weight in kg x prescribed mg/kg/day / doses per day) / medication concentration in mg per mL.
Worked example
For a 20 kg child using 20 mg/kg/day divided 3 times daily with 125 mg/5 mL, calculate the daily mg target, divide by the schedule, then convert that mg amount into mL for the selected product.
Safety checks before using the result
- Use the exact product strength in hand before measuring the dose.
- Confirm maximum dose, age limits, and indication-specific cautions when they apply.
- Escalate urgent symptoms or medication reactions instead of repeating doses from calculator output alone.
Practical dosing guide
Before you measure the dose
Use this page to match the prescribed Cefaclor plan to the exact product strength and schedule before the first dose.
- Common outpatient uses
- Cefaclor is a second-generation cephalosporin used selectively for pediatric infections based on susceptibility and guidelines.
- Common forms
- Common forms include 125 mg/5 mL suspension, 250 mg/5 mL suspension, and 250 mg capsule.
- How the schedule is usually written
- Many outpatient plans are given in divided doses, depending on the reason it was prescribed for 10 days.
Cefaclor pediatric medication summary
Cefaclor is a second-generation cephalosporin used selectively for pediatric infections based on susceptibility and guidelines.
Label pediatric regimen is 20 mg/kg/day divided every 8 hours, or 40 mg/kg/day for ear infections and more serious infections (max 1 g/day); extended-release tablets (500 mg, every 12 hours with meals) are labeled only for age 16 and older.
Administer suspension with food if GI upset occurs; extended-release tablets must be taken within one hour after a meal to ensure adequate absorption.
Cefaclor indications and common pediatric uses
Cefaclor is an oral second-generation cephalosporin used as an alternative therapy for select respiratory, skin, and urinary infections when first-line agents are contraindicated or not tolerated.
Acute otitis media with suspected beta-lactamase producing organisms
Group A streptococcal pharyngitis/tonsillitis
Uncomplicated skin and soft-tissue infections (MSSA, Streptococcus)
Uncomplicated urinary tract infection (susceptible organisms)
Sinusitis step-down therapy after IV cephalosporin
Community-acquired pneumonia (non-MRSA, beta-lactam susceptible)
How to give Cefaclor
- Cefaclor works best when dosing is accurate, consistent, and matched to the exact formulation dispensed (suspension, capsule, or, for age 16 and older only, ER tablet).
- Shake suspension for 10 to 15 seconds before each dose, measure in mL with a calibrated syringe, and follow the prescribed interval (typically q8h or q12h for immediate-release). ER tablets must be swallowed whole within one hour after a meal. Separate cefaclor from iron or antacids by at least 2 hours and do not swap formulations without dose review.
- Anchor doses to consistent routines, set alarms for late doses, and rinse dosing devices after each use. Refrigerate suspension and write the 14-day discard date on the bottle. For school-age and teen patients, keep a written schedule so capsule/tablet doses are not missed.
Cefaclor side effects, contraindications, and interactions
Most cefaclor side effects in children are mild and short-lived, especially diarrhea, nausea, or simple rash. Rare but serious events (anaphylaxis, severe delayed rash/joint reactions, or C. difficile-associated diarrhea) require immediate medical review.
Common side effects
- Give with food to help reduce stomach upset.
- Keep the child hydrated; call for severe or bloody diarrhea.
- Stop immediately and seek urgent care for hives, facial swelling, breathing trouble, or rash with joint pain/fever.
Safety checks
- Documented anaphylaxis or serious hypersensitivity to cefaclor or other cephalosporins
- History of cephalosporin-associated Stevens–Johnson syndrome or toxic epidermal necrolysis
- Immediate IgE-mediated reaction to penicillin or amoxicillin
- Severe renal impairment (creatinine clearance <30 mL/min/1.73 m²)
- History of antibiotic-associated colitis (C. difficile)
- Phenylketonuria when using aspartame-containing suspension
Drug interactions
- Review the full medication list with a clinician or pharmacist before combining therapies.
Cefaclor mechanism and clinical pearls
Cefaclor is a second-generation cephalosporin that kills susceptible bacteria by disrupting cell wall synthesis. It binds penicillin-binding proteins (PBPs), blocks peptidoglycan cross-linking, and causes cell-wall instability with bacterial lysis. Clinical success depends on maintaining time above MIC, so interval adherence is critical. Cefaclor can cover selected respiratory pathogens when susceptibility is likely, but it should not be relied on for MRSA, ESBL-producing gram-negative infections, or other resistant phenotypes.
Reserve cefaclor for indications where first-line options are not tolerated or have not worked as expected, and align choices with local susceptibility patterns.
Extended-release tablets are only for age 16 and older, dosed every 12 hours, and must be taken with meals (within one hour of eating).
Most reported penicillin allergies are viral rashes; documenting reaction details prevents unnecessary broad-spectrum agents.
Frequently asked questions about Cefaclor
Give doses about 8 hours apart—for example, 7 a.m. (breakfast), 3 p.m. (after school), and 11 p.m. (bedtime). Use alarms or a dosing chart so the midday and evening doses aren’t forgotten.
Yes. Food isn’t required but can reduce stomach upset. Extended-release tablets should be taken within one hour after a meal for best absorption.
Cefaclor can be used cautiously in non-anaphylactic penicillin allergies, but tell your clinician exactly what happened. For severe reactions, an alternative may be safer.
Yes. Keep it in the refrigerator, shake well before each dose, and throw away any remaining medicine after 14 days. During travel or school hours, store it in an insulated bag with a cold pack.
Mild loose stools can occur. Call immediately for hives, facial swelling, trouble breathing, joint pain with rash (possible serum sickness), or watery/bloody diarrhea.
Yes, once fever-free for 24 hours and feeling better. Let the school nurse know about the dosing schedule and any needed refrigeration for the lunchtime dose.
Yes—replace toothbrushes 24 hours after starting cefaclor to reduce reinfection risk. If sharing cups or utensils caused the infection to spread in your household, clean them thoroughly.
If your clinician approves, space probiotics 2–3 hours away from antibiotic doses so both work effectively. Probiotics are optional but may help with loose stools.
Sources reviewed for Cefaclor
https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=9f919252-7a87-4386-a64c-5d8213f7e881
https://www.aap.org/en/patient-care/otitis-media/otitis-media-clinical-practice-guideline/
https://www.cdc.gov/group-a-strep/hcp/clinical-guidance/strep-throat.html
https://www.idsociety.org/practice-guideline/skin-and-soft-tissue-infections/
https://www.aap.org/en/patient-care/urinary-tract-infections/diagnosis-and-management/
https://www.entnet.org/resource/clinical-practice-guideline-adult-sinusitis-update/