Cefaclor
Cefaclor is a semisynthetic, second generation cephalosporin antibiotic.
Uses
Cefaclor is used orally for the treatment of mild to moderate upper and lower respiratory tract infections (including pneumonia) caused by susceptible bacteria; acute otitis media caused by susceptible bacteria; pharyngitis and tonsillitis caused by Streptococcus pyogenes (group A b-hemolytic streptococci); and uncomplicated skin and skin structure or urinary tract infections (including pyelonephritis and cystitis) caused by susceptible bacteria.
While commercially available cefaclor capsules and oral suspension can be used for any of these infections, safety and efficacy of cefaclor extended-release tablets have been established only for the treatment of mild to moderate respiratory tract infections (i.e., acute exacerbations of chronic bronchitis, secondary infections of acute bronchitis) caused by susceptible bacteria; pharyngitis and tonsillitis caused by S. pyogenes; and mild to moderate uncomplicated skin and skin structure infections caused by susceptible Staphylococcus aureus (methicillin-susceptible strains only).
Respiratory Tract Infections
Cefaclor capsules and oral suspension are used for the treatment of lower respiratory tract infections (including pneumonia) caused by susceptible S. pneumoniae, H. influenzae, or S. pyogenes. Cefaclor extended-release tablets are used for the treatment of mild to moderate acute exacerbations of chronic bronchitis or secondary infections of acute bronchitis caused by susceptible Haemophilus influenzae (non-b-lactamase-producing strains only), Moraxella (formerly Branhamella) catarrhalis (including b-lactamase-producing strains), or Streptococcus pneumoniae. The manufacturer cautions that data are insufficient to establish efficacy of cefaclor extended-release tablets in the treatment of acute or chronic bronchitis that is known or suspected to be caused by b-lactamase-producing strains of H. influenzae.
The overall clinical response rate (cure or improvement) reported in adults with acute bacterial bronchitis or acute bacterial exacerbations of chronic bronchitis treated with cefaclor capsules (250 mg 3 times daily) is 92% and the overall bacteriologic elimination rate is 80-92%. When results are stratified according to causative agent, the bacteriologic elimination rate is 85% for infections caused by H. influenzae and 100% for those caused by H. parainfluenzae or Klebsiella pneumoniae; 81% for infections caused by S. pneumoniae; and 75% for infections caused by M. catarrhalis.
Otitis Media
Acute Otitis Media
Cefaclor capsules and oral suspension are used for the treatment of acute otitis media caused by S. pneumoniae, H. influenzae, staphylococci, or S. pyogenes (group A b-hemolytic streptococci). Results of controlled clinical studies in pediatric patients with acute otitis media indicate that a 10-day regimen of oral cefaclor generally is as effective as a 10-day regimen of oral amoxicillin, oral cefixime (no longer commercially available in the US), oral cefprozil, or oral ceftibuten.
Cefaclor has been effective for the treatment of acute otitis media in some pediatric patients when administered in a 5-day regimen; however, the shortened regimen appears to be less effective in patients with spontaneous perforation of the tympanic membrane and purulent drainage than in those with intact tympanic membranes.
In a controlled study in children with acute otitis media who were randomized to received 5 or 10 days of oral cefaclor (20 mg/kg twice daily), the treatment failure rate in those with intact tympanic membranes at the time of diagnosis was 10% in those who received the 5-day regimen and 6% in those who received the 10-day regimen; in those with spontaneous perforation of the tympanic membrane at the time of diagnosis, the failure rate was 53 and 8%, respectively.
Further study is needed to evaluate use of a 5-day regimen of oral cefaclor for the treatment of acute otitis media. Some clinicians caution that short-term anti-infective regimens (i.e., 5 days or less) may not be appropriate for the treatment of acute otitis media in children younger than 2 years of age or for patients with underlying disease, recurrent or persistent otitis media, or perforated tympanic membranes with spontaneous purulent drainage.
Cefaclor has been administered as long-term prophylaxis or suppressive therapy in an attempt to prevent further episodes of acute otitis media in children with a history of recurrent acute otitis media; however, anti-infective prophylaxis is not routinely recommended in most children with recurrent acute otitis media because of concerns that such regimens may promote emergence of resistant organisms.
In a retrospective study evaluating use of prophylactic anti-infectives in pediatric patients 1 month to 15 years of age with a history of recurrent AOM (more than 3 episodes of acute otitis media within a 6-month period and/or 6 or more episodes by 18 months of age), patients received a 10-day regimen of oral amoxicillin or oral cefaclor for treatment of the acute episode and then a suppressive regimen of amoxicillin (20 mg/kg once daily) or cefaclor (20 mg/kg once daily) for a mean duration of 8.6 weeks (range: 3-20 weeks).
Results indicate that suppressive therapy failed in 47% of those receiving cefaclor and 70% of those receiving amoxicillin; most of these patients required other interventions (e.g., placement of tympanostomy tubes).
For additional information regarding treatment of acute otitis media, including treatment of persistent or recurrent acute otitis media, see Acute Otitis Media and Persistent or Recurrent Acute Otitis Media, under Uses: Otitis Media in the Cephalosporins General Statement 8:12.06.
Otitis Media with Effusion
Results of a randomized study in children 7 months to 12 years of age with otitis media with effusion indicate that 14 days of treatment with oral cefaclor (40 mg/kg daily in 3 divided doses), oral erythromycin-sulfisoxazole (50 mg/kg of erythromycin and 150 mg/kg of sulfisoxazole daily in 4 divided doses), or oral amoxicillin (40 mg/kg daily in 3 divided doses) are similarly effective for the short-term resolution of otitis media with effusion and are associated with similar rates of recurrence.
At completion of the 14-day regimen, middle ear effusion had resolved in 22% of those who received cefaclor, 21% of those who received erythromycin-sulfisoxazole, and 31.% of those who received amoxicillin; acute otitis media developed during treatment in 2 patient who received cefaclor.
Of those who were effusion-free at 4 weeks, there was recurrence of effusion during the next 12 weeks in 52% of those who received cefaclor, 47% of those who received erythromycin-sulfisoxazole, and 60.% of those who received amoxicillin.
Optimum strategies for the management of otitis media with effusion (residual or persistent middle ear effusion without signs or symptoms of infection; also referred to as noninfected or nonsuppurative otitis media, secretory otitis media, serous otitis media, middle ear effusion, fluid ear, glue ear) have not been identified, and use of anti-infective agent therapy in such patients is controversial.
For additional information regarding treatment of otitis media with effusion, see Otitis Media with Effusion under Uses: Otitis Media, in the Cephalosporins General Statement 8:12.06.
Pharyngitis and Tonsillitis
Cefaclor capsules, oral suspension, and extended-release tablets are used for the treatment of pharyngitis and tonsillitis caused by susceptible S. pyogenes (group A b-hemolytic streptococci).
Although cefaclor usually is effective in eradicating S. pyogenes from the nasopharynx, substantial data to establish efficacy of the drug for prophylaxis of subsequent rheumatic fever are not available to date.
A 10-day regimen of oral cefaclor is at least as effective as a 10-day regimen of oral penicillin V or a 10-day regimen of oral amoxicillin and clavulanate potassium for the treatment of S. pyogenes pharyngitis and tonsillitis. In an open, randomized study in adults and adolescents 12 years of age or older with acute pharyngitis caused by S. pyogenes, a 10-day regimen of oral cefaclor (250 mg 3 times daily) was at least as effective as a 10-day regimen of oral cefprozil (500 mg once daily); the clinical response rate was 85% for both drugs and the bacteriologic eradication rate was 95% in those who received cefaclor and 91% in those who received cefprozil.
In double-blind, randomized multicenter studies designed to compare efficacy of a 10-day regimen of cefaclor capsules (250 mg 3 times daily) and a 10-day regimen of cefaclor extended-release tablets (375 mg twice daily), the clinical response rates were 98. and 96.%, respectively, and the bacteriologic eradication rates were 94. and 93.%, respectively. Selection of an anti-infective agent regimen for the treatment of S. pyogenes pharyngitis and tonsillitis should be based on the drug’s spectrum of activity as well as the regimen’s bacteriologic and clinical efficacy, potential adverse effects, ease of administration and patient compliance, and cost. No regimen has been found to date that effectively eradicates group A b-hemolytic streptococci in 100% of patients.
Because penicillin has a narrow spectrum of activity, is inexpensive, and generally is effective, the US Centers for Disease Control and Prevention (CDC), American Academy of Pediatrics (AAP), American Academy of Family Physicians (AAFP), Infectious Diseases Society of America (IDSA), American Heart Association (AHA), American College of Physicians-American Society of Internal Medicine (ACP-ASIM), and others consider natural penicillins (i.e., 10 days of oral penicillin V or a single IM dose of penicillin G benzathine) the treatment of choice for streptococcal pharyngitis and tonsillitis and prevention of initial attacks (primary prevention) of rheumatic fever, although oral amoxicillin often is used instead of penicillin V in small children because of a more acceptable taste.
Other anti-infectives (e.g., oral cephalosporins, oral macrolides) generally are considered alternatives. There is some evidence that bacteriologic and clinical cure rates reported with 10-day regimens of certain oral cephalosporins (e.g., cefaclor, cefadroxil, cefdinir, cefixime, cefpodoxime proxetil, cefprozil, cefuroxime axetil, ceftibuten, cephalexin) are slightly higher than those reported with the 10-day oral penicillin V regimen. In addition, there is some evidence that a shorter duration of therapy with certain oral cephalosporins (e.g., a 5-day regimen of cefadroxil, cefdinir, cefixime, or cefpodoxime proxetil or a 4- or 5-day regimen of cefuroxime axetil) achieves bacteriologic and clinical cure rates equal to or greater than those achieved with the traditional 10-day oral penicillin V regimen.
Based on these results, some clinicians suggest that oral cephalosporins should be included as agents of choice for the treatment of S. pyogenes pharyngitis and tonsillitis.
However, the IDSA states that first generation cephalosporins can be used for the treatment of pharyngitis in patients hypersensitive to penicillins (except those with immediate-type hypersensitivity to b-lactam anti-infectives) but that cephalosporins appear to offer no advantage over penicillins since they have a broader spectrum of activity and generally are more expensive. In addition, because of limited data to date, the IDSA states that use of cephalosporin regimens administered for 5 days or less for the treatment of S. pyogenes pharyngitis cannot be recommended at this time.
Skin and Skin Structure Infections
Cefaclor capsules, oral suspension, and extended-release tablets are used for the treatment of uncomplicated skin and skin structure infections caused by Staphylococcus aureus (methicillin-susceptible strains only).
Cefaclor capsules and oral suspension also can be used for the treatment of uncomplicated skin and skin structure infections caused by S. pyogenes; however, the manufacturer states that efficacy of cefaclor extended-release tablets for the treatment of uncomplicated skin or skin structure infections known or suspected of being caused by these bacteria has not been established. In a multicenter, randomized study in adults and children 2 years of age or older with mild to moderate bacterial skin and skin structure infections (e.g., carbuncle, cellulitis, folliculitis, furuncle, impetigo, infecteddermatitis, paronychia, pyoderma, superficial abscess, wound infection), patients were randomized to receive 5-10 days of therapy with oral cefaclor (250 mg 3 times daily in adults or 20 mg/kg daily in 3 doses) or oral cefprozil (500 mg once daily in adults or 20 mg/kg once daily in children). Results of this study indicate that cefaclor and cefprozil are equally effective for these infections and similarly tolerated; a satisfactory clinical response was attained in 92 and 93% of patients, respectively, and the bacteriologic eradication rate was 89 and 91%, respectively.
Urinary Tract Infections
Cefaclor capsules and oral suspension are used for the treatment of urinary tract infections (including pyelonephritis and cystitis) caused by susceptible Escherichia coli, Klebsiella, Proteus mirabilis, or coagulase-negative staphylococci.
Dosage and Administration
Administration
Cefaclor is administered orally. Cefaclor extended-release tablets should not be cut, crushed, or chewed. While food does not affect the extent of absorption of cefaclor administered as capsules, food increases the extent of absorption of the drug administered as extended-release tablets.
To enhance GI absorption of the drug, the manufacturer recommends that cefaclor extended-release tablets be administered with meals (i.e., at least within 1 hour of eating).
Administration of an antacid containing magnesium or aluminum hydroxide within 1 hour of a dose of cefaclor administered as extended-release tablets decreases the extent of absorption of the drug.
Dosage
Dosage of cefaclor, which is commercially available as the monohydrate, is expressed as anhydrous cefaclor.
Adult Dosage
The usual adult dosage of cefaclor administered as capsules or oral suspension is 250 mg every 8 hours; for more serious infections or those caused by less susceptible organisms, 500 mg may be given every 8 hours.
Although the daily dosage of cefaclor capsules or oral suspension usually is administered in 3 equally divided doses, the manufacturer states that daily dosage may be given in 2 equally divided doses at 12-hour intervals for the treatment of otitis media or pharyngitis.
Respiratory Tract Infections
For the treatment of acute bacterial exacerbation of chronic bronchitis or secondary bacterial infections of acute bronchitis caused by susceptible H. influenzae (non-b-lactamase-producing strains only), M. catarrhalis (including b-lactamase-producing strains), or S. pneumoniae, the usual adult dosage of cefaclor administered as extended-release tablets is 500 mg every 12 hours for 7 days.
Pharyngitis and Tonsillitis
For the treatment of pharyngitis and/or tonsillitis caused by susceptible S. pyogenes, the usual adult dosage of cefaclor extended-release tablets is 375 mg every 12 hours for 10 days.
Skin and Skin Structure Infections
Adults should receive cefaclor extended-release tablets in a dosage of 375 mg every 12 hours for 7-10 days for the treatment of uncomplicated skin and skin structure infections caused by susceptible S. aureus.
Pediatric Dosage
The usual dosage of cefaclor capsules or oral suspension for children 1 month of age or older is 20 mg/kg daily given in divided doses every 8 hours.
For more serious infections, otitis media, or infections caused by less susceptible organisms, the manufacturer recommends a pediatric dosage of 40 mg/kg daily and a maximum daily dose of 1 g. Although the daily dosage of cefaclor capsules or oral suspension usually is administered in 3 equally divided doses, daily dosage may be given in 2 equally divided doses at 12-hour intervals for the treatment of acute otitis media or pharyngitis.
Safe use of cefaclor capsules or oral suspension in infants younger than 1 month of age has not been established. Safety and efficacy of cefaclor extended-release tablets in children younger than 16 years of age have not been established.
Dosage in Renal Impairment
The manufacturer states that cefaclor should be used with caution in patients with markedly impaired renal function. Modification of usual dosage usually is not necessary in patients with moderate or severe renal impairment.
However, because clinical experience in such patients is limited, close clinical observation and appropriate laboratory tests are recommended in patients with moderate or severe renal impairment.
Cautions
Adverse Effects
Most adverse effects reported with cefaclor are similar to those reported with other oral cephalosporins. (See Cautions in the Cephalosporin General Statement 8:12.06.) The most frequent adverse effects reported with cefaclor include GI effects (diarrhea, nausea, vomiting), headache, and rash.
Serum sickness-like reactions consisting of erythema multiforme or maculopapular pruritic rash or urticaria accompanied by arthritis, arthralgia, irritability, and fever have been reported rarely in patients receiving cefaclor.
These reactions differ from serum sickness type III hypersensitivity reactions since they generally are not associated with lymphadenopathy and proteinuria, circulating immune complexes have not been identified, and sequelae have not been reported. Serum sickness-like reactions have been reported most frequently in pediatric patients younger than 6 years of age receiving cefaclor oral suspension for the treatment of acute otitis media, pharyngitis and tonsillitis, or other upper respiratory tract infection and occur most often with second or subsequent courses of the drug.
Signs and symptoms of the reaction usually are apparent 2-11 days after initiation of cefaclor therapy and begin to subside within a few days after the drug is discontinued. Oral antihistamines and corticosteroids provide symptomatic relief and may enhance resolution of the reaction; short-term (i.e., 2-3 days) hospitalization has been necessary in some patients because of symptoms (e.g., arthralgia) that ranged from mild to severe. The true incidence of serum sickness-like reactions in patients receiving cefaclor is unclear but has been estimated to be 0.5% or lower.
While similar serum sickness-like reactions have been reported rarely in patients receiving other cephalosporins (i.e., cefprozil, cephalexin) or other b-lactam antibiotics (i.e., amoxicillin, loracarbef), these reactions have been reported more frequently with cefaclor than with any other anti-infective agent.
The manufacturer and some clinicians recommend that cefaclor notbe used in patients who have had a serum sickness-like reaction to the drug; however, it has been suggested that a history of a serum sickness-like reaction from cefaclor does not necessarily contraindicate use of other cephalosporins or other b-lactam antibiotics. Severe hypersensitivity reactions, including Stevens-Johnson syndrome, toxic epidermal necrolysis, and anaphylaxis, have been reported rarely with cefaclor.
Anaphylactic reactions may be manifested by solitary symptoms, including angioedema, asthenia, edema (including face and limbs), dyspnea, paresthesia, vertigo, syncope, hypotension, or vasodilation. There has been at least one report of hypersensitivity myocarditis that appeared to be a sensitivity reaction to cefaclor. The manufacturer states that hypersensitivity reactions rarely may persist for several months.
Precautions and Contraindications
Cefaclor shares the toxic potentials of other cephalosporins, and the usual cautions, precautions, and contraindications associated with cephalosporin therapy should be observed. (See Cautions in the Cephalosporins General Statement 8:12.06.)
Prior to initiation of cefaclor therapy, careful inquiry should be made concerning previous hypersensitivity reactions to cephalosporins, penicillins, or other drugs. There is clinical and laboratory evidence of partial cross-allergenicity among cephalosporins and other b-lactam antibiotics, including penicillins and cephamycins.
Cefaclor is contraindicated in patients who are hypersensitive to the drug or other cephalosporins and should be used with caution in patients with a history of hypersensitivity to penicillins.
Use of cephalosporins should be avoided in patients who have had an immediate-type (anaphylactic) hypersensitivity reaction to penicillins. If a hypersensitivity reaction occurs during cefaclor therapy, the drug should be discontinued and the patient treated with appropriate therapy (e.g., epinephrine, corticosteroids, and maintenance of an adequate airway and oxygen) as indicated.
Pediatric Precautions
Safety and efficacy of cefaclor capsules and oral suspension in children younger than 1 month of age have not been established. Safety and efficacy of cefaclor extended-release tablets in children younger than 16 years of age have not been established.
Geriatric Precautions
Safety and efficacy of cefaclor in geriatric adults (i.e., those older than 65 years of age) are similar to those observed in younger adults. Although peak plasma concentrations of cefaclor and the area under the plasma concentration-time curve (AUC) may be higher in geriatric adults with normal serum creatinine values than in younger adults, the manufacturer states that no adjustments in cefaclor dosage appear to be necessary in such geriatric adults.
Mutagenicity and Carcinogenicity
Animal studies have not been performed to date to evaluate the mutagenic and carcinogenic potential of cefaclor.
Pregnancy, Fertitlity and Lactation
Reproduction studies in mice, rats, and ferrets using doses up to 3-5 times the maximum human dosage (1500 mg daily) based on mg/m2 have not revealed evidence of harm to the fetus.
There are no adequate and controlled studies using cefaclor in pregnant women or during labor and delivery, and the drug should be used during pregnancy only when clearly needed.
Reproduction studies in animals using cefaclor have not revealed evidence of impaired fertility.
Because low concentrations of cefaclor (0.-0. mcg/mL) have been detected in milk following a single 500-mg oral dose of the drug, cefaclor should be used with caution in nursing women.
Acute Toxcicity
Overdosage of cefaclor may cause nausea, vomiting, epigastric distress, and diarrhea; the severity of the epigastric distress and diarrhea reportedly is dose related. If other symptoms are present, they probably are secondary to an underlying disease state, an allergic reaction, or the effects of other intoxications.
The manufacturer states that, in the event of cefaclor overdosage, GI decontamination is not necessary unless 5 times the normal dose of cefaclor has been ingested. The benefits of forced diuresis, peritoneal dialysis, hemodialysis, or charcoal hemoperfusion in treating cefaclor overdosage have not been established. Spectrum Based on its spectrum of activity, cefaclor is classified as a second generation cephalosporin.
While cefaclor is less active in vitro against gram-negative bacteria than other currently available second generation cephalosporins, cefaclor is active against some gram-negative bacteria that are generally resistant to the first generation drugs (e.g., Haemophilus influenzae). For information on the classification of cephalosporins and closely related b-lactam antibiotics based on spectra of activity, see Spectrum in the Cephalosporins General Statement 8:12.06.
In Vitro Susceptibility Testing
The National Committee for Clinical Laboratory Standards (NCCLS) states that, if results of in vitro susceptibility testing indicate that a clinical isolate is susceptible to cefaclor, then an infection caused by this strain may be appropriately treated with the dosage of the drug recommended for that type of infection and infecting species, unless otherwise contraindicated. If results indicate that a clinical isolate has intermediate susceptibility to cefaclor, then the strain has a minimum inhibitory concentration (MIC) that approaches usually attainable blood and tissue drug concentrations and response rates may be lower than for strains identified as susceptible.
Therefore, the intermediate category implies clinical applicability in body sites where the drug is physiologically concentrated (e.g., urine) or when a high dosage of the drug can be used.
This intermediate category also includes a buffer zone which should prevent small, uncontrolled technical factors from causing major discrepancies in interpretation, especially for drugs with narrow pharmacotoxicity margins. If results of in vitro susceptibility testing indicate that a clinical isolate is resistant to cefaclor, the strain is not inhibited by systemic concentrations of the drug achievable with usual dosage schedules and/or MICs fall in the range where specific microbial resistance mechanisms are likely and efficacy has not been reliably demonstrated in clinical trials.
Strains of staphylococci resistant to penicillinase-resistant penicillins should be considered resistant to cefaclor, although results of in vitro susceptibility tests may indicate that the organisms are susceptible to the drug. In addition, NCCLS recommends that b-lactamase-negative, ampicillin-resistant (BLNAR) strains of H. influenzae should be considered resistant to cefaclor despite the fact that results of in vitro susceptibility tests may indicate that the organisms are susceptible to the drug.
Disk Susceptibility Tests
When the disk-diffusion procedure is used to test susceptibility to cefaclor, a disk containing 30 mcg of cefaclor should be used. However, NCCLS states that for some organisms (e.g., Enterobacteriaceae), results of disk-diffusion susceptibility tests using the cephalosporin class disk containing 30 mcg of cephalothin may be used to predict susceptibility to cefaclor.
When disk-diffusion susceptibility testing is performed according to NCCLS standardized procedure using NCCLS interpretive criteria, Staphylococcus or Enterobacteriaceae with growth inhibition zones of 18 mm or greater are to cefaclor, those with zones of 15-17 mm have intermediate susceptibility, and those with zones of 14 mm or less are resistant to the drug.
When disk-diffusion susceptibility testing for Haemophilus is performed according to NCCLS standardized procedures using Haemophilus test medium (HTM), Haemophilus with growth inhibition zones of 20 mm or greater are susceptible to cefaclor, those with zones of 17-19 mm have intermediate susceptibility, and those with zones of 16 mm or less are resistant to the drug.
Interpretive criteria are not available to determine susceptibility of Streptococcus to cefaclor using the cefaclor disk; however, NCCLS states that S. pneumoniae found to be susceptible to penicillin using the NCCLS standardized disk-diffusion procedure and a 1-mcg oxacillin disk can be considered susceptible to cefaclor. In addition, other Streptococcus (b-hemolytic streptococci, viridans streptococci) found to be susceptible to penicillin using NCCLS standardized procedures can be considered susceptible to cefaclor.
Dilution Susceptibility Tests
When dilution susceptibility testing (agar or broth dilution) is performed according to NCCLS standardized procedures using NCCLS interpretive criteria, Staphylococcus or Enterobacteriaceae with MICs of 8 mcg/mL or less are susceptible to cefaclor, those with MICs of 16 mcg/mL have intermediate susceptibility, and those with MICs of 32 mcg/mL or greater are resistant to the drug.
When dilution susceptibility testing of Haemophilus is performed according to NCCLS standardized procedures using HTM, Haemophilus with MICs of 8 mcg/mL or less are susceptible to cefaclor, those with MICs of 16 mcg/mL have intermediate susceptibility, and those with MICs of 32 mcg/mL or greater are resistant to the drug.
When broth dilution is performed according to NCCLS standardized procedures using cation-adjusted Mueller-Hinton broth (with 2-5% lysed horse blood), S. pneumoniae with MICs of 1 mcg/mL or less are susceptible to cefaclor, those with MICs of 2 mcg/mL have intermediate susceptibility, and those with MICs of 4 mcg/mL or greater are resistant to the drug. NCCLS states that S. pneumoniae and other Streptococcus (b-hemolytic streptococci, viridans streptococci) found to be susceptible to penicillin using the NCCLS standardized dilution procedure can be considered susceptible to cefaclor.
Pharmacokinetics
Absorption
Cefaclor is acid-stable and is well absorbed from the GI tract. Following oral administration of cefaclor capsules in healthy, fasting adults with normal renal function, peak serum concentrations of cefaclor are attained within 30-60 minutes and average 5-7 mcg/mL following a single 250-mg dose, 13-15 mcg/mL following a single 500-mg dose, and 23-25 mcg/mL following a single 1-g dose.
When 500 mg of cefaclor is administered as capsules, peak plasma concentrations are attained 0.9 hours after the dose and average 16. mcg/mL in fasting individuals; however, in nonfasting individuals, peak plasma concentrations are attained 1.5 hours after the dose and average 9.3 mcg/mL.
In nonfasting individuals who receive 375 mg of cefaclor as an extended-release tablet, peak plasma concentrations of the drug average 3.7 mcg/mL and are attained 2.7 hours after the dose.
Following oral administration 500 mg of cefaclor as an extended-release tablet in fasting individuals, peak plasma concentrations of the drug are attained 1.5 hours after the dose and average 5.4 mcg/mL; when the same dose is given to nonfasting individuals, peak plasma concentrations are attained 2.5 hours after the dose and average 8.2 mcg/mL. Peak serum concentrations are lower and attained later when cefaclor capsules are administered with food, although the total amount of drug absorbed is unchanged.
Administration of cefaclor extended-release tablets with food increases the extent of absorption and peak plasma concentrations of the drug. In one study in infants younger than 18 months of age, peak serum concentrations of cefaclor ranged from 2-14 mcg/mL 1 hour after a single oral dose of 10 mg/kg and 1.2-23 mcg/mL 1 hour after a single oral dose of 15 mg/kg.
Elimination
The serum half-life of cefaclor is 0.5-1 hour in adults with normal renal function. The manufacturer states that the serum half-life of cefaclor in anuric patients is 2.3-2. hours. The serum half-life of cefaclor reportedly was 1.3 hours in 1 adult with a creatinine clearance of 55 mL/minute, 2.5 hours in 1 adult with a creatinine clearance of 10. mL/minute, and 5.6 hours in 1 adult with a creatinine clearance of 8 mL/minute in one study. In another study in functionally anephric patients who were given multiple doses of the drug, the serum half-life averaged 2.9 hours. Cefaclor is excreted unchanged in urine.
Approximately 50-85% of a single oral dose is excreted within 8 hours in adults with normal renal function; the major portion of the dose is excreted within the first 2 hours. In adults with normal renal function, peak concentrations of cefaclor average 600 mcg/mL, 900 mcg/mL, and 1.9 mg/mL in urine collected over an 8-hour period following a single 250-mg, 500-mg, or 1-g dose, respectively.
Chemistry and Stability
Chemistry
Cefaclor is a semisynthetic cephalosporin antibiotic. Cefaclor is commercially available for oral administration as capsules, powder for oral suspension, and extended-release tablets containing cefaclor monohydrate; potency is expressed on the anhydrous basis. Cefaclor occurs as a crystalline powder and is sparingly soluble in water.
Stability
Cefaclor capsules, powder for oral suspension, and extended-release tablets should be stored in tight containers at a temperature between 15-30°C. Following reconstitution, cefaclor oral suspensions are stable for 14 days at 2-8°C; any unused suspension should be discarded after this period.
For further information on chemistry, mechanism of action, spectrum, resistance, pharmacokinetics, uses, cautions, drug interactions, laboratory test interferences, and dosage and administration of cefaclor, see the Cephalosporins General Statement 8:12.06.
Therapeutic classes of Cefaclor:
Anti-Bacterial Agents, Cephalosporins
| Dosage forms of Cefaclor: | |||
|---|---|---|---|
| Raniclor 250 mg chewable tablet | Cefaclor 250 mg capsule | Raniclor 375 mg chewable tablet | Ceclor 250 mg pulvule |
| Cefaclor CR 500 mg 12 Hour tablet | Cefaclor 500 mg capsule | Ceclor 500 mg pulvule | Cefaclor 125 mg/5ml Suspension 75ml Bottle |
| Cefaclor 187 mg/5ml Suspension 50ml Bottle | Cefaclor 375 mg/5ml Suspension 50ml Bottle | Cefaclor 187 mg/5ml Suspension 100ml Bottle | Cefaclor 250 mg/5ml Suspension 75ml Bottle |
| Cefaclor 125 mg/5ml Suspension 150ml Bottle | Ceclor 250 mg/5ml Suspension 75ml Bottle | Ceclor 125 mg/5ml Suspension 150ml Bottle | Ceclor 187 mg/5ml Suspension 100ml Bottle |
| Ceclor 15 250 mg capsule Bottle | Cefaclor 250 mg/5ml Suspension 150ml Bottle | Cefaclor 375 mg/5ml Suspension 100ml Bottle | Ceclor 250 mg/5ml Suspension 150ml Bottle |
| Ceclor 375 mg/5ml Suspension 100ml Bottle | Ceclor 15 500 mg capsule Bottle | ||
Synonyms of Cefaclor:
CCL, Cefaclor Anhydrous, Cefaclorum [INN-Latin], Cephaclor
Prescription
This medicine is available from a pharmacist and requires a prescription.
How can i get Cefaclor online over the counter?
You can buy Cefaclor OTC in online drugstore with low cost.
Delivery
Australia, Canada, Mexico, New Zealand, USA, Europe [Belgium, France, Norway, Holland, Ireland, Spain, Switzerland, Great Britain (UK), Italy] and etc.