CEFACLOR: 1,053 Adverse Event Reports & Safety Profile

DESCRIPTION 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

250-mg capsule contains cefaclor monohydrate equivalent to 250 mg (0.68 mmol) of anhydrous cefaclor and inactive ingredients: magnesium stearate, sodium starch glycolate, lactose monohydrate, talc.

The

250 mg capsule shell contains gelatin, titanium dioxide, FD & C Blue No. 1, FD & C Red No. 3, and imprinting ink components: shellac, strong ammonia solution, potassium hydroxide, black iron oxide, .dehydrated alcohol, isopropyl alcohol, butyl alcohol and propylene glycol.

Each

500-mg capsule contains cefaclor monohydrate equivalent to 500 mg (1.36 mmol) of anhydrous cefaclor and inactive ingredients: magnesium stearate, sodium starch glycolate, lactose monohydrate, talc.

The

500 mg capsule shell contains gelatin, titanium dioxide, FD & C Blue No. 1, FD & C Red No. 3, FD & C Yellow No. 6, FD & C Red No. 40, and imprinting ink components: shellac, strong ammonia solution, titanium dioxide, FD & C Blue No. 1 aluminum lake, dehydrated alcohol, isopropyl alcohol, butyl alcohol and propylene glycol. image description

INDICATIONS AND USAGE To reduce the development of drug-resistant bacteria and maintain the effectiveness of cefaclor extended-release tablets USP and other antibacterial drugs, cefaclor extended-release tablets USP should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy. The safety and effectiveness of cefaclor extended-release tablets in treating some of the indications and pathogens for which other formulations of cefaclor are approved have NOT been established. When administered at the recommended dosages and durations of therapy, cefaclor extended-release tablets are indicated for the treatment of patients with the following mild to moderate infections when caused by susceptible strains of the designated organisms. (See DOSAGE AND ADMINISTRATION and CLINICAL STUDIES sections.) Acute bacterial exacerbations of chronic bronchitis due to Haemophilus influenzae (excluding ß-lactamase-negative, ampicillin-resistant isolates), Moraxella catarrhalis, or Streptococcus pneumoniae . NOTE: In view of the insufficient numbers of isolates of ß-lactamase-producing isolates of Haemophilus influenzae that were obtained from clinical trials with cefaclor extended-release tablets for patients with acute bacterial exacerbations of chronic bronchitis, it was not possible to adequately evaluate the effectiveness of cefaclor extended-release tablets for bronchitis known, suspected, or considered potentially to be caused by ß-lactamase-producing H. influenzae . Pharyngitis and tonsillitis due to Streptococcus pyogenes . NOTE: Only penicillin by the intramuscular route of administration has been shown to be effective in the prophylaxis of rheumatic fever. Cefaclor extended-release tablets are generally effective in the eradication of S. pyogenes from the oropharynx; however, data establishing the efficacy of cefaclor extended-release tablets for the prophylaxis of subsequent rheumatic fever are not available. Uncomplicated skin and skin and structure infections due to Staphylococcus aureus (methicillin-susceptible only). NOTE: In view of the insufficient numbers of isolates of Streptococcus pyogenes that were obtained from clinical trials with cefaclor extended-release tablets for patients with uncomplicated skin and skin structure infections, it was not possible to adequately evaluate the effectiveness of cefaclor extended-release tablets for skin infections known, suspected, or considered potentially to be caused by S. pyogenes .

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.

Table

1: Cefaclor for Oral Suspension, USP 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.

Table

2: Cefaclor for Oral Suspension, USP 20 mg/kg/day (Pharyngitis)

Weight

375 mg/5 mL 18 kg 1/2 tsp b.i.d. 40 mg/kg/day (Otitis Media) 9 kg 1/2 tsp b.i.d. 18 kg 1 tsp b.i.d. 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 250 mg anhydrous cefaclor, respectively, as shown in the following table. Oversize bottle provides extra space for shaking.

Table

3: Cefaclor For Oral Suspension, USP Strength Package Size (when mixed)

Water

Volume to Add Anhydrous Cefaclor/5 mL (approx. one teaspoonful) 250 mg/5 Ml 150 mL 106 mL 250 mg

CONTRAINDICATIONS Cefaclor extended-release tablets are contraindicated in patients with known hypersensitivity to cefaclor and other cephalosporins.

ADVERSE REACTIONS Clinical Trials There were 3272 patients treated with multiple doses of cefaclor extended-release tablets in controlled clinical trials and an additional 211 subjects in pharmacology studies. There were no deaths in these trials thought to be related to toxicity from cefaclor extended-release tablets. Treatment was discontinued in 1.7% of patients due to adverse events thought to be possibly or probably drug-related. The following adverse clinical and laboratory events were reported during the cefaclor extended-release tablets clinical trials conducted in North America at doses of 375 mg or 500 mg BID; however, relatedness of the adverse events to the drug was not assigned by clinical investigators during the trials (see TABLES 4 and 5 ).

Table

4: ADVERSE CLINICAL EVENTS - CEFACLOR EXTENDED-RELEASE TABLETS MULTIPLE DOSE DOSING REGIMENS CLINICAL TRIALS - NORTH AMERICA (n = 1400)

Incidence

Equal to or Greater Than 1% Event Incidence Headache 4.9% Rhinitis 3.9% Diarrhea 3.8% Nausea 3.4% Vaginitis n = 934 for these events (subset of female participants). 2.4% Vaginal Moniliasis 2.2% Abdominal Pain 1.6% Cough Increased 1.5% Pharyngitis 1.4% Pruritus 1.4% Back Pain 1.0% Adverse reactions occurring during the clinical trials with cefaclor extended-release tablets with an incidence of less than 1% but greater than 0.1% included the following (listed alphabetically): Accidental injury, anorexia, anxiety, arthralgia, asthma, bronchitis, chest pain, chills, congestive heart failure, conjunctivitis, constipation, dizziness, dysmenorrhea, dyspepsia, dysuria, ear pain, edema, fever, flatulence, flu syndrome, gastritis, infection, insomnia, leukorrhea, lung disorder, maculopapular rash, malaise, menstrual disorder, myalgia, nausea and vomiting, neck pain, nervousness, nocturia, otitis media, pain, palpitation, peripheral edema, rash, respiratory disorder, sinusitis, somnolence, surgical procedure, sweating, tremor, urticaria, vomiting. NOTE: One case of serum-sickness-like reaction was reported among the 3272 adult patients treated with cefaclor extended-release tablets during the controlled clinical trials. These reactions have also been reported with the use of cefaclor in other oral formulations and are seen more frequently in pediatric patients than in adults. These reactions are characterized by findings of erythema multiforme, rash, 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. 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 cefaclor. Such reactions have been reported with overall occurrence ranging from 1 in 200 (0.5%) in one focused trial; to 2 in 8346 (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 patients 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.

Table

5: ADVERSE CLINICAL LABORATORY EVENTS CEFACLOR EXTENDED-RELEASE TABLETS MULTIPLE DOSE DOSING REGIMENS CLINICAL TRIALS – NORTH AMERICA Event Incidence Incidence Less Than 1%, but Greater Than 0.1% Albumin decreased 0.3% Alkaline phosphatase increased 0.3% ALT/SGPT increased 0.3% Bilirubin total increased 0.3% Blood urea nitrogen (BUN) increased 0.2% Calcium decreased 0.7% Creatine phosphokinase increased 0.7% Creatinine increased 0.5% Eosinophils increased 0.3% Erythrocyte count decreased 0.3% GGT increased 0.2% Hemoglobin decreased 0.2% Lymphocytes decreased 0.3% Mean Cell Volume (MCV) increased 0.7% Neutrophils segmented decreased 0.3% Phosphorous increased 0.7% Platelet count decreased 0.3% Potassium increased 0.4% Sodium decreased 0.3% Sodium increased 0.4% In Postmarketing Experience In addition to the events reported during clinical trials with cefaclor extended-release tablets, the following adverse experiences are among those that have been reported during worldwide postmarketing surveillance: allergic reaction, anaphylactoid reaction, angioedema, face edema, hypotension, Stevens-Johnson syndrome, syncope, paresthesia, vasodilatation and vertigo.

Other Adverse Reactions Associated With

Other Formulations of Cefaclor In addition to the above, the following other adverse reactions and altered laboratory tests have been associated with cefaclor in other oral formulations: Clinical 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, edema (including face and limbs), paresthesias, syncope, or vasodilatation. Anaphylaxis may be more common in patients with a history of penicillin allergy. Rarely, hypersensitivity symptoms may persist for several months. Symptoms of pseudomembranous colitis may appear either during or after antibiotic treatment. (See WARNINGS .)

Laboratory

Abnormal urinalysis, eosinophilia, leukopenia, neutropenia, transient elevations in AST, and transient thrombocytopenia have been reported. Cephalosporin-Class Reactions In addition to the adverse reactions listed above, the following adverse reactions and altered laboratory tests have been reported for cephalosporin-class antibiotics: Clinical Confusion, erythema multiforme, genital pruritus, hepatic dysfunction including cholestasis, hemolytic anemia, reversible hyperactivity, hypertonia, and reversible interstitial nephritis.

Laboratory

Positive direct Coombs’ test.

WARNINGS BEFORE THERAPY WITH CEFACLOR IS INSTITUTED, CAREFUL INQUIRY SHOULD BE MADE TO DETERMINE WHETHER THE PATIENT HAS HAD PREVIOUS HYPERSENSITIVITY REACTIONS TO CEFACLOR, CEPHALOSPORINS, PENICILLINS, OR OTHER DRUGS. IF THIS PRODUCT IS TO BE GIVEN TO PENICILLIN- SENSITIVE PATIENTS, CAUTION SHOULD BE EXERCISED BECAUSE CROSS-HYPERSENSITIVITY AMONG β-LACTAM ANTIBIOTICS HAS BEEN CLEARLY DOCUMENTED AND MAY OCCUR IN UP TO 10% OF PATIENTS WITH A HISTORY OF PENICILLIN ALLERGY. IF AN ALLERGIC REACTION TO CEFACLOR OCCURS, DISCONTINUE THE DRUG. SERIOUS ACUTE HYPER-SENSITIVITY REACTIONS MAY REQUIRE TREATMENT WITH EPINEPHRINE AND OTHER EMERGENCY MEASURES, INCLUDING OXYGEN, INTRAVENOUS FLUIDS, INTRAVENOUS ANTIHISTAMINES, CORTICOSTEROIDS, PRESSOR AMINES, AND AIRWAY MANAGEMENT, AS CLINICALLY INDICATED. Antibiotics, including cefaclor, should be administered cautiously to any patient who has demonstrated some form of allergy, particularly to drugs. Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including Cefaclor for Oral Suspension, USP, and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile . C. difficile produces toxins A and B which contribute to the 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 is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents. If CDAD is 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.

PRECAUTIONS 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 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 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 ).

Drug Interactions Antacids The extent of absorption of cefaclor extended-release tablets is diminished if magnesium or aluminum hydroxide-containing antacids are taken within 1 hour of administration; H 2 blockers do not alter either the rate or the extent of absorption of cefaclor extended-release tablets.

Probenecid

The renal excretion of cefaclor is inhibited by probenecid.

Warfarin

There have been rare reports of increased prothrombin time with or without clinical bleeding in patients receiving cefaclor and warfarin concomitantly. No specific studies have been performed to rule in or rule out this potential drug/drug interaction.