Ceclor® (Cefaclor, USP) is a semisynthetic cephalosporin antibiotic for oral administration. It is chemically designated as 3-chloro-7-D- (2-phenylglycinamido)-3-cephem-4-carboxylic acid monohydrate. The chemical formula for cefaclor is C 15 H 14 ClN 3 O 4 S · H 2 O and the molecular weight is 385.82.


Each Pulvule® contains cefaclor monohydrate equivalent to 250 mg (0.68 mmol) or 500 mg (1.36 mmol) anhydrous cefaclor. The Pulvules also contain cornstarch, F D & C Blue No. 1, F D & C Red No. 40, gelatin, magnesium stearate, silicone, titanium dioxide, and other inactive ingredients. The 500-mg Pulvule also contains iron oxide.

After mixing, each 5 mL of Ceclor for Oral Suspension will contain cefaclor monohydrate equivalent to 125 mg (0.34 mmol), 187 mg (0.51 mmol), 250 mg (0.68 mmol), or 375 mg (1.0 mmol) anhydrous cefaclor. The suspensions also contain cellulose, cornstarch, F D & C Red No. 40, flavors, silicone, sodium lauryl sulfate, sucrose, and xanthan gum.

Cefaclor is well absorbed after oral administration to fasting subjects. Total absorption is the same whether the drug is given with or without food; however, when it is taken with food, the peak concentration achieved is 50% to 75% of that observed when the drug is administered to fasting subjects and generally appears from three fourths to 1 hour later. Following administration of 250-mg, 500-mg, and 1-g doses to fasting subjects, average peak serum levels of approximately 7, 13, and 23 µg/mL respectively were obtained within 30 to 60 minutes. Approximately 60% to 85% of the drug is excreted unchanged in the urine within 8 hours, the greater portion being excreted within the first 2 hours. During this 8-hour period, peak urine concentrations following the 250-mg, 500-mg, and 1-g doses were approximately 600, 900, and 1,900 µg/mL respectively. The serum half-life in normal subjects is 0.6 to 0.9 hours. In patients with reduced renal function, the serum half-life of cefaclor is slightly prolonged. In those with complete absence of renal function, the plasma half-life of the intact molecule is 2.3 to 2.8 hours. Excretion pathways in patients with markedly impaired renal function have not been determined. Hemodialysis shortens the half-life by 25% to 30%.

Microbiology -- In vitro tests demonstrate that the bactericidal action of the cephalosporins results from inhibition of cell-wall synthesis. Cefaclor has been shown to be active against most strains of the following microorganisms, both in vitro and in clinical infections as described in the section.

Aerobes, Gram-positive

Staphylococci, including coagulase-positive, coagulase-negative, and penicillinase-producing strains

Streptococcus pneumoniae

Streptococcus pyogenes (group A (beta)-hemolytic streptococci)

Aerobes, Gram-negative

Escherichia coli

Haemophilus influenzae, excluding (beta)-lactamase-negative ampicillin-resistant strains

Klebsiella spp

Proteus mirabilis

The following in vitro data are available, but their clinical significance is unknown.

Cefaclor exhibits in vitro minimal inhibitory concentrations (MICs) of </=8 µg/mL against most (>/=90%) strains of the following microorganisms; however, the safety and effectiveness of cefaclor in treating clinical infections due to these microorganisms have not been established in adequate and well-controlled clinical trials.

Aerobes, Gram-negative

Citrobacter diversus

Moraxella (Branhamella) catarrhalis

Neisseria gonorrhoeae

Anaerobes, Gram-positive

Bacteroides spp. (excluding Bacteroides fragilis )



Propionibacterium acnes

Note:  Pseudomonas spp., Acinetobacter calcoaceticus and most strains of enterococci ( Enterococcus faecalis , group D streptococci), Enterobacter spp., indole-positive Proteus , and Serratia spp. are resistant to cefaclor. When tested by in vitro methods, staphylococci exhibit cross-resistance between cefaclor and methicillin-type antibiotics.

Susceptibility Testing--

Dilution Techniques --Quantitative methods that are used to determine minimum inhibitory concentrations (MIC) provide reproducible estimates of the susceptibility of bacteria to antimicrobial compounds. One such standardized procedure that has been recommended for use with cefaclor powder uses a standardized dilution method 1 (broth, agar, or microdilution). The MIC values obtained should be interpreted according to the following criteria:

MIC (µg/mL)
Interpretation *
Susceptible (S)
Resistant (R)
* When testing H. influenzae spp. these interpretive standards are applicable only to broth microdilution method using Haemophilus Test Medium (HTM) 1

Note: (beta)-lactamase-negative, ampicillin-resistant strains of H. influenzae should be considered resistant to cefaclor despite apparent in vitro susceptibility to this agent.

A report of "Susceptible" indicates that the pathogen is likely to be inhibited by usually achievable concentrations of the antimicrobial compound in blood. A report of "Intermediate" indicates that the result should be considered equivocal, and, if the microorganism is not fully susceptible to alternative, clinically feasible drugs, the test should be repeated. This category implies possible clinical applicability in body sites where the drug is physiologically concentrated or in situations where high dosage of drug can be used. This category also provides a buffer zone that prevents small uncontrolled technical factors from causing major discrepancies in interpretation. A report of "Resistant" indicates that usually achievable concentrations of the antimicrobial compound in the blood are unlikely to be inhibitory and that other therapy should be selected.

Standardized susceptibility test procedures require the use of laboratory control microorganisms. Standard cefaclor powder should provide the following MIC values:

MIC (µg/mL)
E. coli ATCC 25922
E. faecalis ATCC 29212
S. aureus ATCC 29213
When testing H. influenzae *
MIC (µg/mL)
H. influenzae ATCC 49766
* Broth microdilution test performed using Haemophilus Test Medium (HTM) 1

Diffusion Techniques --Quantitative methods that require measurement of zone diameters provide reproducible estimates of the susceptibility of bacteria to antimicrobial compounds. One such standardized procedure 2 that has been recommended for use with disks to test the susceptibility of microorganisms to cefaclor uses the 30-µg cefaclor disk. Interpretation involves correlation of the diameter obtained in the disk test with the MIC for cefaclor. Reports from the laboratory providing results of the standard single-disk susceptibility test with a 30-µg cefaclor disk should be interpreted according to the following criteria:

When Testing Organisms Other Than Haemophilus spp. and Streptococci

Zone Diameter (mm)
Susceptible (S)
Resistant (R)
When testing H. influenzae *
Zone Diameter (mm)
Susceptible (S)
Resistant (R)
* Disk susceptibility test performed using Haemophilus Test Medium (HTM) 2

Note: (beta)-lactamase-negative, ampicillin-resistant strains of H. influenzae should be considered resistant to cefaclor despite apparent in vitro susceptibility to this agent.

Interpretation should be as stated above for results using diffusion techniques.

As with standard dilution techniques, diffusion methods require the use of laboratory control microorganisms. The 30-µg cefaclor disk should provide the following zone diameters in these laboratory test quality control strains:

Zone Diameter (mm)
E. coli ATCC 25922
S. aureus ATCC 25923
When testing H. influenzae *
Zone Diameter (mm)
H. influenzae ATCC 49766
* Disk susceptibility test performed using Haemophilus Test Medium (HTM) 1

Ceclor is indicated in the treatment of the following infections when caused by susceptible strains of the designated microorganisms.

Otitis media caused by Streptococcus pneumoniae , Haemophilus influenzae , staphylococci, and Streptococcus pyogenes

Note: (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.

Lower respiratory tract infections , including pneumonia, caused by Streptococcus pneumoniae , Haemophilus influenzae , and Streptococcus pyogenes

Note: (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.

Pharyngitis and Tonsillitis , caused by Streptococcus pyogenes

Note: Penicillin is the usual drug of choice in the treatment and prevention of streptococcal infections, including the prophylaxis of rheumatic fever. Ceclor is generally effective in the eradication of streptococci from the nasopharynx; however, substantial data establishing the efficacy of Ceclor in the subsequent prevention of rheumatic fever are not available at present.

Urinary tract infections , including pyelonephritis and cystitis, caused by Escherichia coli, Proteus mirabilis, Klebsiella spp., and coagulase-negative staphylococci

Skin and skin structure infections caused by Staphylococcus aureus and Streptococcus pyogenes

Appropriate culture and susceptibility studies should be performed to determine susceptibility of the causative organism to cefaclor.


Ceclor is contraindicated in patients with known allergy to the cephalosporin group of antibiotics.



Antibiotics, including Ceclor, should be administered cautiously to any patient who has demonstrated some form of allergy, particularly to drugs.

Pseudomembranous colitis has been reported with nearly all antibacterial agents, including cefaclor, and has ranged in severity from mild to life-threatening. Therefore, it is important to consider this diagnosis in patients who present with diarrhea subsequent to the administration of antibacterial agents.

Treatment with antibacterial agents alters the normal flora of the colon and may permit overgrowth of clostridia. Studies indicate that a toxin produced by Clostridium difficile is one primary cause of antibiotic-associated colitis.

After the diagnosis of pseudomembranous colitis has been established, therapeutic measures should be initiated. Mild cases of pseudomembranous colitis usually respond to drug discontinuation alone. In moderate to severe cases, consideration should be given to management with fluids and electrolytes, protein supplementation and treatment with an antibacterial drug effective against C. difficile .


General --Prolonged use of Ceclor 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, eg, 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.

Ceclor 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 (beta)-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.

Drug/Laboratory Test Interactions --Patients receiving Ceclor may show a false-positive reaction for glucose in the urine with tests that use Benedict' and Fehling' solutions and also with Clinitest® tablets.

There have been reports of increased anticoagulant effect when Ceclor 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--Teratogenic Effects--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 Ceclor. 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 Ceclor on labor and delivery is unknown.

Nursing Mothers --Small amounts of Ceclor have been detected in mother' milk following administration of single 500-mg doses. Average levels were 0.18, 0.20, 0.21, and 0.16 µg/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 Ceclor 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.


Adverse effects considered to be related to therapy with Ceclor are listed below:

Hypersensitivity reactions have been reported in about 1.5% of patients and include morbilliform eruptions (1 in 100). Pruritus, urticaria, and positive Coombs' tests each occur in less than 1 in 200 patients.

Cases of serum-sickness-like reactions have been reported with the use of Ceclor. These are characterized by findings of erythema multiforme, rashes, and other skin manifestations accompanied by arthritis/arthralgia, with or without fever, and differ from classic serum sickness in that there is infrequently associated lymphadenopathy and proteinuria, no circulating immune complexes, and no evidence to date of sequelae of the reaction. Occasionally, solitary symptoms may occur, but do not represent a serum-sickness-like reaction. While further investigation is ongoing, serum-sickness-like reactions appear to be due to hypersensitivity and more often occur during or following a second (or subsequent) course of therapy with Ceclor. Such reactions have been reported more frequently in pediatric patients than in adults with an overall occurrence ranging from 1 in 200 (0.5%) in one focused trial to 2 in 8,346 (0.024%) in overall clinical trials (with an incidence in pediatric patients in clinical trials of 0.055%) to 1 in 38,000 (0.003%) in spontaneous event reports. Signs and symptoms usually occur a few days after initiation of therapy and subside within a few days after cessation of therapy; occasionally these reactions have resulted in hospitalization, usually of short duration (median hospitalization = 2 to 3 days, based on postmarketing surveillance studies). In those requiring hospitalization, the symptoms have ranged from mild to severe at the time of admission with more of the severe reactions occurring in pediatric patients. Antihistamines and glucocorticoids appear to enhance resolution of the signs and symptoms. No serious sequelae have been reported.

More severe hypersensitivity reactions, including Stevens-Johnson syndrome, toxic epidermal necrolysis, and anaphylaxis have been reported rarely. Anaphylactoid events may be manifested by solitary symptoms, including angioedema, asthenia, edema (including face and limbs), dyspnea, paresthesias, syncope, hypotension, or vasodilatation. Anaphylaxis may be more common in patients with a history of penicillin allergy.

Rarely, hypersensitivity symptoms may persist for several months.

Gastrointestinal symptoms occur in about 2.5% of patients and include diarrhea (1 in 70).

Onset of pseudomembranous colitis symptoms may occur during or after antibiotic treatment. ( see ). Nausea and vomiting have been reported rarely. As with some penicillins and some other cephalosporins, transient hepatitis and cholestatic jaundice have been reported rarely.

Other effects considered related to therapy included eosinophilia (1 in 50 patients), genital pruritus or vaginitis (less than 1 in 100 patients), and, rarely, thrombocytopenia or reversible interstitial nephritis.

Causal Relationship Uncertain--

CNS --Rarely, reversible hyperactivity, agitation, nervousness, insomnia, confusion, hypertonia, dizziness, hallucinations, and somnolence have been reported.

Transitory abnormalities in clinical laboratory test results have been reported. Although they were of uncertain etiology, they are listed below to serve as alerting information for the physician.

Hepatic --Slight elevations of AST, ALT, or alkaline phosphatase values (1 in 40).

Hematopoietic -As has also been reported with other (beta)-lactam antibiotics, transient lymphocytosis, leukopenia, and, rarely, hemolytic anemia, aplastic anemia, agranulocytosis, and reversible neutropenia of possible clinical significance.

There have been rare reports of increased prothrombin time with or without clinical bleeding in patients receiving Ceclor and Coumadin® concomitantly.

Renal --Slight elevations in BUN or serum creatinine (less than 1 in 500) or abnormal urinalysis (less than 1 in 200).

Cephalosporin-class Adverse Reactions

In addition to the adverse reactions listed above that have been observed in patients treated with cefaclor, the following adverse reactions and altered laboratory tests have been reported for cephalosporin-class antibiotics: fever, abdominal pain, superinfection, renal dysfunction, toxic nephropathy, hemorrhage, false positive test for urinary glucose, elevated bilirubin, elevated LDH, and pancytopenia.

Several cephalosporins have been implicated in triggering seizures, particularly in patients with renal impairment when the dosage was not reduced. If seizures associated with drug therapy occur, the drug should be discontinued. Anticonvulsant therapy can be given if clinically indicated ( see DOSAGE AND ADMINISTRATION and OVERDOSAGE sections).


Signs and Symptoms --The toxic symptoms following an overdose of cefaclor may include nausea, vomiting, epigastric distress, and diarrhea. The severity of the epigastric distress and the diarrhea are dose related. If other symptoms are present, it is probable that they are secondary to an underlying disease state, an allergic reaction, or the effects of other intoxication.

Treatment --To obtain up-to-date information about the treatment of overdose, a good resource is your certified Regional Poison Control Center. Telephone numbers of certified poison control centers are listed in the Physicians' Desk Reference ( PDR ). In managing overdosage, consider the possibility of multiple drug overdoses, interaction among drugs, and unusual drug kinetics in your patient.

Unless 5 times the normal dose of cefaclor has been ingested, gastrointestinal decontamination will not be necessary.

Protect the patient' airway and support ventilation and perfusion. Meticulously monitor and maintain, within acceptable limits, the patient' vital signs, blood gases, serum electrolytes, etc. Absorption of drugs from the gastrointestinal tract may be decreased by giving activated charcoal, which, in many cases, is more effective than emesis or lavage; consider charcoal instead of or in addition to gastric emptying. Repeated doses of charcoal over time may hasten elimination of some drugs that have been absorbed. Safeguard the patient' airway when employing gastric emptying or charcoal.

Forced diuresis, peritoneal dialysis, hemodialysis, or charcoal hemoperfusion have not been established as beneficial for an overdose of cefaclor.


Ceclor 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.

  Ceclor Suspension
  20 mg/kg/day
Weight 125 mg/5 mL 250 mg/5 mL
9 kg 1/2 tsp t.i.d.  
18 kg 1 tsp t.i.d. 1/2 tsp t.i.d.
  40 mg/kg/day
9 kg 1 tsp t.i.d. 1/2 tsp t.i.d.
18 kg   1 tsp t.i.d.

B.I.D. Treatment Option --For the treatment of otitis media and pharyngitis, the total daily dosage may be divided and administered every 12 hours.

  Ceclor Suspension
  20 mg/kg/day
Weight 187 mg/5 mL 375 mg/5 mL
9 kg 1/2 tsp b.i.d.  
18 kg 1 tsp b.i.d 1/2 tsp b.i.d.
  40 mg/kg/day
(Otitis Media)
9 kg 1 tsp b.i.d. 1/2 tsp b.i.d.
18 kg   1 tsp b.i.d.

Ceclor 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 (beta)-hemolytic streptococcal infections, a therapeutic dosage of Ceclor should be administered for at least 10 days.



250 mg, purple and white (No. 3061)-- (RxPak * of 15) NDC 0002-3061-15;
(100s) NDC 0002-3061-02; (ID # 100) NDC 0002-3061-33

500 mg, purple and gray (No. 3062)--(RxPak of 15) NDC 0002-3062-15

For Oral Suspension:

125 mg/5 mL, strawberry flavor (M-5057 & )--(150-mL size) NDC 0002-5057-68

187 mg/5 mL, strawberry flavor (M-5130 & )--(100-mL size) NDC 0002-5130-48

250 mg/5 mL, strawberry flavor (M-5058 & )--(75-mL size) NDC 0002-5058-18;
(150-mL size) NDC 0002-5058-68

375 mg/5 mL, strawberry flavor (M-5132 & )--(100-mL size) NDC 0002-5132-48

* All RxPaks (prescription packages, Lilly) have safety closures.
# Identi-Dose® (unit dose medication, Lilly).
& After mixing, store in a refrigerator. Shake well before using. Keep tightly closed. The mixture may be kept for 14 days without significant loss of potency. Discard unused portion after 14 days.

Store at 25°C (77°F); excursions permitted to 15-30°C(59-86°F) [See USP Controlled Room Temperature]


  1. National Committee for Clinical Laboratory Standards. Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria that Grow Aerobically--Fourth Edition. Approved Standard NCCLS Document M7-A4, Vol. 17, No. 2, NCCLS, Wayne, PA, January, 1997.
  2. National Committee for Clinical Laboratory Standards. Performance Standards for Antimicrobial Disk Susceptibility Tests--Sixth Edition Approved Standard NCCLS Document M2-A6, Vol. 17, No. 1, NCCLS, Wayne, PA, January, 1997.

Literature issued May 12, 2000

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