Dosing & Uses
Dosage Forms and Strengths
capsule
- 250mg
- 500mg
tablet, extended-release
- 500mg
Lower Respiratory Tract Infections
Lower respiratory tract infections, including pneumonia, caused by Streptococcus pneumoniae, Haemophilus influenzae, and Streptococcus pyogenes
Capsules: 250-500 mg PO q8hr
Otitis Media
Otitis media caused by Streptococcus pneumoniae, Haemophilus influenzae, staphylococci, and Streptococcus pyogenes
Capsules: 250-500 mg PO q8hr
Uncomplicated Skin and Skin Structure Infections
Skin and skin structure infections cause by Staphylococcus aureus and Streptococcus pyogenes
Capsules: 250-500 mg PO q8hr
Extended-release tablets: 375 mg PO q12hr for 7-10 days
Urinary Tract Infections
Urinary tract infections, including pyelonephritis and cystitis, caused by Escherichia coli, Proteus mirabilis, Klebsiella spp, and coagulase-negative staphylococci
Capsules: 250-500 mg PO q8hr
Bronchitis
Acute bacterial exacerbations of chronic bronchitis or secondary bacterial infections of acute bronchitis due to Haemophilus influenzae (excluding beta-lactamase-negative, ampicillin-resistant strains), Moraxella catarrhalis, or Streptococcus pneumoniae
Extended-release tablets: 500 mg PO q12hr for 7 days
Pharyngitis and Tonsillitis
Pharyngitis and tonsillitis due to Streptococcus pyogenes
Capsules: 250-500 mg PO q8hr
Extended-release tablets: 750 mg PO q12hr for 10 days
Dosage Modifications
Renal or hepatic impairment: No dosage adjustments provided
Dosing Considerations
Beta-lactamase-negative, ampicillin-resistant (BLNAR) strains of Haemophilus influenzae should be considered resistant to cefaclor despite apparent in vitro susceptibility of some BLNAR strains
Capsules: In treating beta-hemolytic streptococcal infections, duration of therapy should be at least 10 days
Formulation equivalency
- 500 mg q12hr of cefaclor extended-release tablets are clinically equivalent to 250 mg q8hr of cefaclor capsules
- 500 mg BID of cefaclor extended-release tablets is NOT equivalent to 500 mg q8hr of other cefaclor formulations
Dosage Forms and Strengths
capsule
- 250mg
- 500mg
tablet, extended-release
- 500mg
oral suspension
- 125 mg/5 mL
- 250 mg/5 mL
- 375 mg/5 mL
Lower Respiratory Tract Infections
Capsules and suspension
- <1 month: Safety and efficacy not established
- ≥1 month: 20-40 mg/kg/day PO divided q8hr; not to exceed 1 g/day
Otitis Media
Otitis media caused by Streptococcus pneumoniae, Haemophilus influenzae, staphylococci, and Streptococcus pyogenes
Capsules and suspension
- <1 month: Safety and efficacy not established
- ≥1 month: 20-40 mg/kg/day PO divided q8-12hr; not to exceed 1 g/day
Uncomplicated Skin and Skin Structure Infections
Skin and skin structure infections caused by Staphylococcus aureus and Streptococcus pyogenes
Capsules and suspension
- <1 month: Safety and efficacy not established
- ≥1 month: 20-40 mg/kg/day PO divided q8hr; not to exceed 1 g/day
Extended-release tablets
- <16 years: Safety and efficacy not established
- ≥16 years: 375 PO q12hr for 7-10 days
Bronchitis
Acute bacterial exacerbations of chronic bronchitis or secondary bacterial infections of acute bronchitis due to Haemophilus influenzae (excluding beta-lactamase-negative, ampicillin-resistant strains), Moraxella catarrhalis, or Streptococcus pneumoniae
Extended-release tablets
- <16 years: Safety and efficacy not established
- ≥16 years: 500 mg PO q12hr for 7 days
Pharyngitis and Tonsillitis
Pharyngitis and tonsillitis due to Streptococcus pyogenes
Capsules and suspension
- <1 month: Safety and efficacy not established
- ≥1 month: 20-40 mg/kg/day PO divided q8-12hr; not to exceed 1 g/day
Extended-release tablets
- <16 years: Safety and efficacy not established
- ≥16 years: 750 mg PO q12hr for 10 days
Dosage Modifications
Renal or hepatic impairment: No dosage adjustments provided
Dosing Considerations
Beta-lactamase-negative, ampicillin-resistant (BLNAR) strains of Haemophilus influenzae should be considered resistant to cefaclor despite apparent in vitro susceptibility of some BLNAR strains
Capsules: In treating beta-hemolytic streptococcal infections, duration of therapy should be at least 10 days
Formulation equivalency
- 500 mg q12hr of cefaclor extended-release tablets are clinically equivalent to 250 mg q8hr of cefaclor capsules
- 500 mg BID of cefaclor extended-release tablets is NOT equivalent to 500 mg q8hr of other cefaclor formulations
Consider decreased renal function when prescribing and carefully monitor
Interactions
Interaction Checker
No Results

Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor

Contraindicated (0)
Serious - Use Alternative (4)
- BCG vaccine live
cefaclor decreases effects of BCG vaccine live by pharmacodynamic antagonism. Contraindicated. Wait until Abx Tx complete to administer live bacterial vaccine.
- cholera vaccine
cefaclor, cholera vaccine. pharmacodynamic antagonism. Avoid or Use Alternate Drug. Avoid coadministration of cholera vaccine with systemic antibiotics since these agents may be active against the vaccine strain. Do not administer cholera vaccine to patients who have received oral or parenteral antibiotics within 14 days prior to vaccination.
- microbiota oral
cefaclor decreases effects of microbiota oral by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Microbiota oral contains bacterial spores. Antibacterial agents may decrease efficacy if coadministered. Complete antibiotic regimens 2-4 days before initiating microbiota oral. .
- typhoid vaccine live
cefaclor decreases effects of typhoid vaccine live by pharmacodynamic antagonism. Contraindicated. Wait until Abx Tx complete to administer live bacterial vaccine.
Monitor Closely (11)
- bazedoxifene/conjugated estrogens
cefaclor will decrease the level or effect of bazedoxifene/conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- dienogest/estradiol valerate
cefaclor will decrease the level or effect of dienogest/estradiol valerate by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor. An alternate or additional form of birth control may be advisable during concomitant use.
- estradiol
cefaclor will decrease the level or effect of estradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- ethinylestradiol
cefaclor will decrease the level or effect of ethinylestradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- levonorgestrel oral/ethinylestradiol/ferrous bisglycinate
cefaclor will decrease the level or effect of levonorgestrel oral/ethinylestradiol/ferrous bisglycinate by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor. Antibiotics may decrease hormonal contraceptive efficacy.
- mestranol
cefaclor will decrease the level or effect of mestranol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- pretomanid
pretomanid will increase the level or effect of cefaclor by Other (see comment). Modify Therapy/Monitor Closely. In vitro studies demonstrated that pretomanid significantly inhibits OAT3; monitor for increased adverse effects and consider dosage reduction for OAT3 substrates.
- probenecid
cefaclor will increase the level or effect of probenecid by acidic (anionic) drug competition for renal tubular clearance. Use Caution/Monitor.
- sodium picosulfate/magnesium oxide/anhydrous citric acid
cefaclor decreases effects of sodium picosulfate/magnesium oxide/anhydrous citric acid by altering metabolism. Use Caution/Monitor. Coadministration with antibiotics decreases efficacy by altering colonic bacterial flora needed to convert sodium picosulfate to active drug.
- voclosporin
voclosporin, cefaclor. Either increases toxicity of the other by nephrotoxicity and/or ototoxicity. Modify Therapy/Monitor Closely. Coadministration with drugs associated with nephrotoxicity may increase the risk for acute and/or chronic nephrotoxicity.
- warfarin
cefaclor increases effects of warfarin by unspecified interaction mechanism. Use Caution/Monitor.
Minor (9)
- bendroflumethiazide
cefaclor will increase the level or effect of bendroflumethiazide by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- chloramphenicol
chloramphenicol decreases effects of cefaclor by pharmacodynamic antagonism. Minor/Significance Unknown.
- choline magnesium trisalicylate
cefaclor will increase the level or effect of choline magnesium trisalicylate by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- furosemide
cefaclor increases toxicity of furosemide by pharmacodynamic synergism. Minor/Significance Unknown. Increased risk of nephrotoxicity.
- piroxicam
cefaclor will increase the level or effect of piroxicam by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- rose hips
rose hips will increase the level or effect of cefaclor by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- salicylates (non-asa)
cefaclor will increase the level or effect of salicylates (non-asa) by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- sulfasalazine
cefaclor will increase the level or effect of sulfasalazine by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- willow bark
cefaclor will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
Adverse Effects
1-10%
Diarrhea (3%)
Increased transaminases (3%)
Eosinophilia (2%)
Moniliasis (2%)
Vaginitis (2%)
Rash (maculopapular, erythematous, or morbiliform) (1-2%)
<1%
Stevens-Johnson syndrome
Pseudomembranous colitis
Nausea
Vomiting
Anemia
Neutropenia
Jaundice
Warnings
Contraindications
Documented hypersensitivity
Cautions
Prescribing drug in absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to patient and increases risk of development of drug-resistant bacteria
Superinfection (overgrowth by non-susceptible organisms) should always be considered a possibility in patient being treated with broad spectrum antimicrobial; careful observation of patient is essential; take appropriate measures if superinfection occurs during therapy
Reduce dosage by 1/2 if creatinine clearance is 10-30 mL/min, and by 3/4 if <10 mL/min (high doses may cause CNS toxicity); bacterial or fungal overgrowth of non-susceptible organisms may occur with prolonged or repeated therapy
Clostridium difficile associated diarrhea (CDAD)
- CDAD has been reported with use and may range in severity from mild diarrhea to fatal colitis; treatment with antibacterial agents alters normal flora of colon leading to overgrowth of C. difficile
- C. difficile produces toxins A and B which contribute to development of CDAD; hypertoxin producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy
- CDAD must be considered in all patients who present with diarrhea following antibiotic use; careful medical history necessary since CDAD has been reported to occur over two months after administration of antibacterial agents
- If CDAD suspected or confirmed, ongoing antibiotic use not directed against C. difficile may need to be discontinued; appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile, and surgical evaluation should be instituted as clinically indicated
Pregnancy & Lactation
Pregnancy
No adequate and well-controlled studies in pregnant women
Because animal reproduction studies are not always predictive of human response, cefaclor should be used during pregnancy only if necessary
Lactation
Effect on nursing infants is unknown; exercise caution when cefaclor is administered to a nursing woman
Extended-release tablets
- No studies in lactating women performed; small amounts of cefaclor (≤0.21 mcg/mL) detected in human milk following administration (single 500-mg dose of cefaclor extended-release tablets)
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Second-generation cephalosporin that binds to one or more of the penicillin-binding proteins, which in turn inhibits cell wall synthesis and results in bactericidal activity
Has gram-positive activity that first-generation cephalosporins have and adds activity against Proteus mirabilis, H influenzae, Escherichia coli, Klebsiella pneumoniae, and Moraxella catarrhalis
Absorption
Peak serum concentrations: ~7 mcg/mL (250-mg dose); ~13 mcg/mL (500-mg dose); 23 mcg/mL (1-gram dose)
Effects of food
- Peak concentration achieved is 50-75% of that observed when administered to fasting subjects and generally appears from 0.75-1 hr later
Elimination
Half-life: 0.6-0.9 hr
Hemodialysis shortens half-life by 25-30%
Excretion: Urine (~60-80%, unchanged)
Administration
Oral Suspension Preparation
Add 106 mL (125-mg or 250-mg bottle) or 68 mL (375-mg bottle) of water in two portions to dry mixture
Shake well after each addition
Each 5 mL (~1 tsp) will contain 125 mg, 250 mg, and 375 mg of cefaclor depending on package size
Oral Administration
Capsules and oral suspension: Administer without regard to meals; shake oral suspension well before using
Extended-release tablets: Do not chew, crush, or split; administer with or within 1 hr of food
Storage
Capsules, extended-release tablets, and dry powder for suspension: Store at 20-25°C (68-77°F)
Reconstituted oral suspension: Refrigerate for up to 14 days after mixing
Images
BRAND | FORM. | UNIT PRICE | PILL IMAGE |
---|---|---|---|
cefaclor oral - | 500 mg capsule | ![]() | |
cefaclor oral - | 250 mg/5 mL suspension | ![]() | |
cefaclor oral - | 375 mg/5 mL suspension | ![]() | |
cefaclor oral - | 250 mg capsule | ![]() | |
cefaclor oral - | 500 mg tablet | ![]() |
Copyright © 2010 First DataBank, Inc.
Patient Handout
cefaclor oral
CEFACLOR SUSPENSION - ORAL
(SEFF-uh-klor)
COMMON BRAND NAME(S): Ceclor
USES: This medication is a cephalosporin-type antibiotic used to treat a wide variety of bacterial infections (such as middle ear, skin, urine and respiratory tract infections). It works by stopping the growth of bacteria.This antibiotic only treats bacterial infections. It will not work for viral infections (such as common cold, flu). Unnecessary use or overuse of any antibiotic can lead to its decreased effectiveness.
HOW TO USE: Shake the bottle well before each dose. Take this medication by mouth with or without food as directed by your doctor, usually every 8 or 12 hours. You may take this medicine with food if stomach upset occurs.For the best effect, take this antibiotic at evenly spaced times. To help you remember, take this medication at the same time(s) every day.Continue to take this medication until the full prescribed amount is finished, even if symptoms disappear after a few days. Stopping the medication too early may result in a return of the infection.Tell your doctor if your condition lasts or gets worse.
SIDE EFFECTS: Stomach upset, headache, nausea, vomiting, or diarrhea may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Tell your doctor right away if you have any serious side effects, including: nausea/vomiting that doesn't stop, stomach/abdominal pain, yellowing eyes or skin, dark urine, unusual joint pain, new signs of infection (such as sore throat or fever that doesn't go away), easy bruising/bleeding, signs of kidney problems (such as change in the amount of urine), mental/mood changes (such as confusion).This medication may rarely cause a severe intestinal condition due to a bacteria called C. difficile. This condition may occur during treatment or weeks to months after treatment has stopped. Tell your doctor right away if you develop: diarrhea that doesn't stop, abdominal or stomach pain/cramping, blood/mucus in your stool.If you have these symptoms, do not use anti-diarrhea or opioid products because they may make symptoms worse.Use of this medication for prolonged or repeated periods may result in oral thrush or a new vaginal yeast infection (oral or vaginal fungal infection). Contact your doctor if you notice white patches in your mouth, a change in vaginal discharge or other new symptoms.A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
PRECAUTIONS: Before taking cefaclor, tell your doctor or pharmacist if you are allergic to it; or to penicillins or other cephalosporins; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney disease, intestinal disease (colitis).Cefaclor may cause live bacterial vaccines (such as typhoid vaccine) to not work well. Tell your health care professional that you are using cefaclor before having any immunizations/vaccinations.Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.This medication passes into breast milk. Consult your doctor before breast-feeding.
DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.This medication may interfere with certain lab tests (such as certain diabetic urine tests), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.
OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include severe vomiting, seizures.
NOTES: Do not share this medication with others.This medication has been prescribed for your current condition only. Do not use it later for another infection unless your doctor tells you to.
MISSED DOSE: If you miss a dose, use it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Use your next dose at the regular time. Do not double the dose to catch up.
STORAGE: Follow the label instructions about whether or not to refrigerate. Do not freeze. Do not store in the bathroom. Discard any unused portion after 14 days. Keep all medications away from children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
Information last revised September 2023. Copyright(c) 2023 First Databank, Inc.
IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.
Formulary
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