Yes — infection has been reported as a side effect of Cefaclor in FDA adverse-event reports (FAERS) and product labeling. It is among the more frequently reported events for this medication. These are voluntary reports, so they show what's been reported, not how often it happens.
Reported adverse reactions
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
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.
Yes — infection has been reported as a side effect of Cefaclor in FDA adverse-event reports (FAERS) and/or its labeling. These are voluntary reports, so they show what's been reported, not how often it happens.
How common is infection with Cefaclor?
infection is among the more frequently reported events for Cefaclor in FAERS. Reporting volume isn't a true incidence rate — check the prescribing information for documented frequencies.
What should I do if I have infection while taking Cefaclor?
Don't stop a prescribed medication on your own. Tell your prescriber or pharmacist — they can tell you whether it's expected, whether it needs attention, and what to do next.
Informational only, drawn from FDA adverse-event reporting (FAERS) and labeling — not medical advice, and not proof a medication caused an effect. Talk to your clinician or pharmacist about any side effect.
Look up another medication
Powered by Eleplan
Tracking a side effect is easier when the whole plan is in one place.
Log symptoms, keep every medication and its history, and prep questions for your next visit — with Ellie, your AI care assistant, on top of it all. Free to start.