Cefaclor

Cefoxitin is a cephalosporin (SEF a low spor in) antibiotic. It works by fighting bacteria in your body.

Cefaclor is used to treat many kinds of bacterial infections, such as bladder infection, ear infection, skin infection, or infection of the respiratory tract.

Cefaclor may also be used for purposes not listed in this medication guide.

You should not use this medication if you are allergic to cefoxitin or to similar antibiotics, such as cefdinir (Omnicef), cefprozil (Cefzil), cefuroxime (Ceftin), cephalexin (Keflex), and others.

Antibiotic medicines can cause diarrhea, which may be a sign of a new infection. If you have diarrhea that is watery or bloody, call your doctor. Do not use anti-diarrhea medicine unless your doctor tells you to.

Usual Adult Dose for Bronchitis:

Acute bacterial exacerbation of chronic bronchitis or secondary bacterial infection of acute bronchitis:
Immediate-release: 250 to 500 mg orally every 8 hours
Extended-release: 500 mg orally every 12 hours with food
Duration: 7 days

Usual Adult Dose for Otitis Media:

Immediate-release: 250 to 500 mg orally every 8 hours for 10 to 14 days

Usual Adult Dose for Pneumonia:

Mild to moderate:
Immediate-release: 500 mg orally every 8 hours for 10 to 21 days

Usual Adult Dose for Pyelonephritis:

Mild to moderate:
Immediate-release: 500 mg orally every 8 hours for 14 days

Usual Adult Dose for Sinusitis:

Immediate-release: 250 to 500 mg orally every 8 hours for 10 to 14 days
Extended-release: 375 mg orally every 12 hours with food
Duration: 10 to 14 days. Longer courses of therapy, sometimes 3 to 4 weeks, may be required for refractory or recurrent cases.

Usual Adult Dose for Skin or Soft Tissue Infection:

Uncomplicated:
Immediate-release: 250 to 500 mg orally every 8 hours
Extended-release: 375 mg orally every 12 hours with food
Duration: 7 to 10 days

Usual Adult Dose for Tonsillitis/Pharyngitis:

Immediate-release: 250 to 500 mg orally every 8 hours
Extended-release: 375 mg orally every 12 hours with food
Duration: 10 days

Usual Adult Dose for Upper Respiratory Tract Infection:

Mild to moderate:
Immediate-release: 250 to 500 mg orally every 8 hours for 10 days
Extended-release: 375 mg orally every 12 hours with food
Duration: 10 days

Usual Adult Dose for Urinary Tract Infection:

Immediate-release: 250 to 500 mg orally every 8 hours for 3 to 10 days

Usual Pediatric Dose for Otitis Media:

1 month or older:
Immediate-release: 20 to 40 mg/kg/day orally in divided doses every 8 or 12 hours; do not exceed 1 g/day
Duration: At least 10 days

Usual Pediatric Dose for Tonsillitis/Pharyngitis:

1 month or older:
Immediate-release: 20 to 40 mg/kg/day orally in divided doses every 8 or 12 hours; do not exceed 1 g/day
Duration: At least 10 days

Usual Pediatric Dose for Cystitis:

1 month or more:
Immediate-release: 20 to 40 mg/kg/day orally in divided doses every 8 or 12 hours; do not exceed 1 g/day

Usual Pediatric Dose for Pneumonia:

1 month or more:
Immediate-release: 20 to 40 mg/kg/day orally in divided doses every 8 or 12 hours; do not exceed 1 g/day

Usual Pediatric Dose for Pyelonephritis:

1 month or more:
Immediate-release: 20 to 40 mg/kg/day orally in divided doses every 8 or 12 hours; do not exceed 1 g/day

Usual Pediatric Dose for Urinary Tract Infection:

1 month or more:
Immediate-release: 20 to 40 mg/kg/day orally in divided doses every 8 or 12 hours; do not exceed 1 g/day

Usual Pediatric Dose for Skin and Structure Infection:

1 month or more:
Immediate-release: 20 to 40 mg/kg/day orally in divided doses every 8 or 12 hours; do not exceed 1 g/day

Antibacterial; β-lactam antibiotic; second generation cephalosporin.167 168 169 a

Acute Otitis Media (AOM)

Treatment of AOM caused by Streptococcus pneumoniae, Haemophilus influenzae, staphylococci, or S. pyogenes (group A β-hemolytic streptococci).167 169 (See Haemophilus influenzae Infections under Cautions.)

When anti-infectives indicated, AAP recommends high-dose amoxicillin or amoxicillin and clavulanate as drugs of choice for initial treatment of AOM; certain cephalosporins (cefdinir, cefpodoxime, cefuroxime, ceftriaxone) recommended as alternatives for initial treatment in penicillin-allergic patients without a history of severe and/or recent penicillin-allergic reactions.165

Pharyngitis and Tonsillitis

Treatment of pharyngitis and tonsillitis caused by S. pyogenes (group A β-hemolytic streptococci).124 135 152 153 167 168 169 Generally effective in eradicating S. pyogenes from nasopharynx; efficacy in prevention of subsequent rheumatic fever not established to date.167 168 169

AAP, IDSA, AHA, and others recommend a penicillin regimen (10 days of oral penicillin V or oral amoxicillin or single dose of IM penicillin G benzathine) as treatment of choice for S. pyogenes pharyngitis and tonsillitis;100 101 116 117 other anti-infectives (oral cephalosporins, oral macrolides, oral clindamycin) recommended as alternatives in penicillin-allergic patients.100 101 116 117

If an oral cephalosporin used, 10 day regimen of first generation cephalosporin (cefadroxil, cephalexin) preferred instead of other cephalosporins with broader spectrums of activity (e.g., cefaclor, cefdinir, cefixime, cefpodoxime, cefuroxime).100 116 117

Respiratory Tract Infections

Treatment of lower respiratory tract infections, including pneumonia, caused by susceptible H. influenzae, S. pneumoniae, or S. pyogenes (group A β-hemolytic streptococci).167 169 (See Haemophilus influenzae Infections under Cautions.)

Treatment of mild to moderate acute bacterial exacerbations of chronic bronchitis caused by susceptible H. influenzae (β-lactamase negative strains only), Moraxella catarrhalis (including β-lactamase producing strains), or S. pneumoniae.168 (See Haemophilus influenzae Infections under Cautions.)

Treatment of secondary bacterial infections of acute bronchitis caused by susceptible H. influenzae (β-lactamase negative strains only) or M. catarrhalis (including β-lactamase producing strains).168 (See Haemophilus influenzae Infections under Cautions.)

Skin and Skin Structure Infections

Uncomplicated skin and skin structure infections caused by susceptible Staphylococcus aureus (methicillin-susceptible [oxacillin-susceptible] strains only)136 167 168 169 or S. pyogenes.136 167

Urinary Tract Infections (UTIs)

Treatment of UTIs (including pyelonephritis and cystitis) caused by susceptible Escherichia coli, Proteus mirabilis, Klebsiella, or coagulase-negative staphylococci.167

Storage

Oral

20–25°C; protect from moisture.167

20–25°C.169 After reconstitution, store suspension in tight container in the refrigerator; discard after 14 days.169

20–25°C.168

General

Prescribing Cefaclor in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increase the risk of the development of drug-resistant bacteria.

Prolonged use of Cefaclor may result in the overgrowth of nonsusceptible organisms. Careful observation of the patient is essential. If superinfection occurs during therapy, appropriate measures should be taken.

Positive direct Coombs' tests have been reported during treatment with the cephalosporin antibiotics. It should be recognized that a positive Coombs' test may be due to the drug, e.g., in hematologic studies or in transfusion cross-matching procedures when antiglobulin tests are performed on the minor side or in Coombs' testing of newborns whose mothers have received cephalosporin antibiotics before parturition.

Cefaclor should be administered with caution in the presence of markedly impaired renal function. Since the half-life of Cefaclor in anuria is 2.3 to 2.8 hours, dosage adjustments for patients with moderate or severe renal impairment are usually not required. Clinical experience with Cefaclor under such conditions is limited; therefore, careful clinical observation and laboratory studies should be made.

As with other β-lactam antibiotics, the renal excretion of Cefaclor is inhibited by probenecid.

Antibiotics, including cephalosporins, should be prescribed with caution in individuals with a history of gastrointestinal disease, particularly colitis.

Information for Patients

Patients should be counseled that antibacterial drugs including Cefaclor for Oral Suspension should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold). When Cefaclor for Oral Suspension is prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed. Skipping dose or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by Cefaclor for Oral Suspension or other antibacterial drugs in the future.

Diarrhea is a common problem caused by antibiotics which usually ends when the antibiotic is discontinued. Sometimes after starting treatment with antibiotics, patients can develop watery and bloody stools (with or without stomach cramps and fever) even as late as two or more months after having taken the last dose of the antibiotic. If this occurs, patients should contact their physician as soon as possible.

Drug/Laboratory Test Interactions

Patients receiving Cefaclor may show a false-positive reaction for glucose in the urine with tests that use Benedict's and Fehling's solutions and also with Clinitest® tablets.

There have been reports of increased anticoagulant effect when Cefaclor and oral anticoagulants were administered concomitantly.

Carcinogenesis, Mutagenesis, Impairment of Fertility

Studies have not been performed to determine potential for carcinogenicity, mutagenicity, or impairment of fertility.

Pregnancy

Pregnancy Category B

Reproduction studies have been performed in mice and rats at doses up to 12 times the human dose and in ferrets given 3 times the maximum human dose and have revealed no harm to the fetus due to Cefaclor. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

Labor and Delivery

The effect of Cefaclor on labor and delivery is unknown.

Nursing Mothers

Small amounts of Cefaclor have been detected in mother's milk following administration of single 500 mg doses. Average levels were 0.18, 0.20, 0.21, and 0.16 mcg/mL at 2, 3, 4, and 5 hours, respectively. Trace amounts were detected at 1 hour. The effect on nursing infants is not known. Caution should be exercised when Cefaclor is administered to a nursing woman.

Pediatric Use

Safety and effectiveness of this product for use in infants less than 1 month of age have not been established.

Geriatric Use

Of the 3,703 patients in clinical studies of Cefaclor, 594 (16.0%) were 65 and older. No overall differences in safety or effectiveness were observed between these subjects and younger subjects.

Other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.

This drug is known to be substantially excreted by the kidney (see CLINICAL PHARMACOLOGY), and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function (see DOSAGE AND ADMINISTRATION).

Cefaclor is administered orally.

Adults

The usual adult dosage is 250 mg every 8 hours. For more severe infections (such as pneumonia) or those caused by less susceptible organisms, doses may be doubled.

Pediatric Patients

The usual recommended daily dosage for pediatric patients is 20 mg/kg/day in divided doses every 8 hours. In more serious infections, otitis media, and infections caused by less susceptible organisms, 40 mg/kg/day are recommended, with a maximum dosage of 1 g/day.

For the treatment of otitis media and pharyngitis, the total daily dosage may be divided and administered every 12 hours.

Cefaclor may be administered in the presence of impaired renal function. Under such a condition, the dosage usually is unchanged (see PRECAUTIONS).

In the treatment of β-hemolytic streptococcal infections, a therapeutic dosage of Cefaclor should be administered for at least 10 days.

Directions for Mixing

Add appropriate water volume as indicated in the following table in two portions to dry mixture in the bottle. Shake well after each addition.

Each 5 mL (approximately one teaspoonful) will then contain Cefaclor, USP, monohydrate equivalent to 125 mg, 250 mg or 375 mg anhydrous Cefaclor, respectively, as shown in the following table.

Oversize bottle provides extra space for shaking.

Inhibits bacterial cell wall synthesis by binding to one or more of the penicillin-binding proteins (PBPs), which in turn inhibits the final transpeptidation step of peptidoglycan synthesis in bacterial cell walls, thus inhibiting cell wall biosynthesis. Bacteria eventually lyse due to ongoing activity of cell wall autolytic enzymes (autolysins and murein hydrolases) while cell wall assembly is arrested.

Absorption

Oral: Well absorbed; acid stable

Distribution

Distributes into tissues and fluids including bone, pleural and synovial fluid

Excretion

Urine (60% to 85% as unchanged drug)

Time to Peak

Capsules, oral suspension: 30 to 60 minutes; Extended-release tablets: 2.5 hours

Half-Life Elimination

0.6 to 0.9 hours; prolonged with renal impairment (2.3 to 2.8 hours in anuria)

Protein Binding

25% (Aronoff 2007)

Acute bacterial exacerbations of chronic bronchitis (extended-release tablets only): Treatment of acute bacterial exacerbations of chronic bronchitis due to Haemophilus influenzae (excluding beta-lactamase-negative, ampicillin-resistant strains only), Moraxella catarrhalis, or Streptococcus pneumoniae.

Lower respiratory tract infections (capsules and oral suspension only): Treatment of lower respiratory tract infections, including pneumonia, caused by S. pneumoniae, H. influenzae, and Streptococcus pyogenes.

Otitis media (capsules and oral suspension only): Treatment of otitis media caused by S. pneumoniae, H. influenzae, staphylococci, and S. pyogenes.

Pharyngitis and tonsillitis: Treatment of pharyngitis and tonsillitis due to S. pyogenes.

Secondary bacterial infections of acute bronchitis (extended-release tablets only): Treatment of secondary bacterial infections of acute bronchitis due to H. influenzae (excluding beta-lactamase negative, ampicillin-resistant strains), M. catarrhalis, or S. pneumoniae.

Skin and skin structure infections, uncomplicated: Treatment of uncomplicated skin and skin structure infections due to Staphylococcus aureus (methicillin-susceptible) or S. pyogenes (capsules and oral suspension only).

Urinary tract infections (capsules and oral suspension only): Treatment of urinary tract infections, including pyelonephritis and cystitis, caused by Escherichia coli, Proteus mirabilis, Klebsiella spp, and coagulase-negative staphylococci.

Treatment of susceptible infections: Oral:

Immediate-release: 250 to 500 mg every 8 hours

Extended-release: 500 mg every 12 hours

Indication-specific dosing: Note: An extended-release tablet dose of 500 mg twice daily is clinically equivalent to an immediate-release capsule dose of 250 mg 3 times daily; an extended-release tablet dose of 500 mg twice daily is NOT clinically equivalent to 500 mg 3 times daily of other cefaclor formulations.

Acute bacterial exacerbations of chronic bronchitis: Oral: Extended-release: 500 mg every 12 hours for 7 days

Secondary bacterial infection of acute bronchitis: Oral: Extended-release: 500 mg every 12 hours for 7 days

Store at 20°C to 25°C (68°F to 77°F). Refrigerate suspension after reconstitution and discard after 14 days.

Aminoglycosides: Cephalosporins (2nd Generation) may enhance the nephrotoxic effect of Aminoglycosides. Monitor therapy

BCG (Intravesical): Antibiotics may diminish the therapeutic effect of BCG (Intravesical). Avoid combination

BCG Vaccine (Immunization): Antibiotics may diminish the therapeutic effect of BCG Vaccine (Immunization). Monitor therapy

Cholera Vaccine: Antibiotics may diminish the therapeutic effect of Cholera Vaccine. Avoid combination

Lactobacillus and Estriol: Antibiotics may diminish the therapeutic effect of Lactobacillus and Estriol. Monitor therapy

Probenecid: May increase the serum concentration of Cephalosporins. Monitor therapy

Sodium Picosulfate: Antibiotics may diminish the therapeutic effect of Sodium Picosulfate. Management: Consider using an alternative product for bowel cleansing prior to a colonoscopy in patients who have recently used or are concurrently using an antibiotic. Consider therapy modification

Teriflunomide: May increase the serum concentration of OAT3 Substrates. Monitor therapy

Typhoid Vaccine: Antibiotics may diminish the therapeutic effect of Typhoid Vaccine. Only the live attenuated Ty21a strain is affected. Management: Vaccination with live attenuated typhoid vaccine (Ty21a) should be avoided in patients being treated with systemic antibacterial agents. Use of this vaccine should be postponed until at least 3 days after cessation of antibacterial agents. Consider therapy modification

Vitamin K Antagonists (eg, warfarin): Cephalosporins may enhance the anticoagulant effect of Vitamin K Antagonists. Monitor therapy

Monitor renal function. Observe for signs of anaphylaxis during first dose.

Mild to moderate:
Immediate-release: 250 to 500 mg orally every 8 hours for 10 days
Extended-release: 375 mg orally every 12 hours with food
Duration: 10 days

1 month or older:
Immediate-release: 20 to 40 mg/kg/day orally in divided doses every 8 or 12 hours; do not exceed 1 g/day
Duration: At least 10 days

Clostridium difficile associated diarrhea (CDAD) has been reported with almost all antibiotics and may potentially be life-threatening. Therefore, it is important to consider this diagnosis in patients who present with diarrhea following cephalosporin therapy. Mild cases generally improve with discontinuation of the drug, while severe cases may require supportive therapy and treatment with an antimicrobial agent effective against C difficile. Hypertoxin producing strains of C difficile cause increased morbidity and mortality; these infections can be resistant to antimicrobial treatment and may necessitate colectomy.

Cephalosporins may be associated with a fall in prothrombin activity. Risk factors include renal or hepatic impairment, poor nutritional state, a protracted course of antimicrobial therapy, and chronic anticoagulation therapy. Prothrombin times should be monitored and vitamin K therapy initiated if indicated.

Serious and occasionally fatal hypersensitivity reactions have been reported with antibiotics. The drug should be discontinued immediately at the first appearance of a skin rash or other signs of hypersensitivity. Severe, acute hypersensitivity reactions may require treatment with epinephrine and other resuscitative measures including oxygen, intravenous fluids, antihistamines, corticosteroids, cardiovascular support and airway management as clinically indicated.

Caution is recommended in patients with significant renal impairment and monitoring is recommended. Some cephalosporins have been associated with seizures in renally impaired patients with elevated serum concentrations. The drug should be discontinued if seizures occur.

Patients with phenylketonuria should be aware that some formulations (e.g., chewable tablets) contain phenylalanine.

Aluminum- or magnesium-containing antacids should not be given within 1 hour of extended-release cefaclor tablets.

Efficacy of the extended-release formulation has not been established for the treatment of skin and soft tissue infections due to Streptococcus pyogenes.

Safety and efficacy of the extended release formulation have not been established in children less than 18 years.

Summary of Use during Lactation

Cefaclor is acceptable to use during breastfeeding. Limited information indicates that maternal cefaclor produces low levels in milk that are not expected to cause adverse effects in breastfed infants. Occasionally, disruption of the infant's gastrointestinal flora, resulting in diarrhea or thrush, has been reported with cephalosporins, but these effects have not been adequately evaluated.

Drug Levels

Maternal Levels. A single dose of cefaclor 250 mg was given orally to 2 nursing mothers. In one mother it was undetectable in milk. In the other, levels of 0.15 to 0.19 mg/L occurred 2 to 4 hours after the dose; by 5 hours it was undetectable. In 5 mothers who received a single 500 mg oral dose, an average peak level of 0.21 mg/L occurred 4 hours after the dose. In individual patients, peak levels of 0.18 to 0.35 mg/L occurred 2 to 5 hours after the dose.[1]

Infant Levels. Relevant published information was not found as of the revision date.

Effects in Breastfed Infants

In a telephone follow-up study, 5 nursing mothers reported taking cefaclor (dosage unspecified). One mother reported diarrhea in her infant. No rashes or candidiasis were reported among the exposed infants.[2]

Effects on Lactation and Breastmilk

Relevant published information was not found as of the revision date.

References

1. Takase Z, Shirafuji H, Uchida M. Clinical and laboratory studies of cefaclor in the field of obstetrics and gynecology. Chemotherapy (Tokyo). 1979;27(Suppl 7):666-72.

2. Ito S, Blajchman A, Stephenson M et al. Prospective follow-up of adverse reactions in breast-fed infants exposed to maternal medication. Am J Obstet Gynecol. 1993;168:1393-9. PMID: 8498418

Substance Name

Cefaclor

CAS Registry Number

53994-73-3

Drug Class

Antiinfective Agents

Antibacterial Agents

Cephalosporins