The majority of adverse reactions observed in clinical trials of Cefaclor prolonged-release tablets were mild and transient. Drug-related adverse reactions requiring discontinuation of therapy occurred in 1.7% of patients.
The following adverse reactions were reported in clinical trials. Incidence rates were less than 1 in 100 (less than 1%), except as stated:
Gastro-intestinal: Diarrhoea (3.4%), nausea (2.5%), vomiting and dyspepsia.
Hypersensitivity: Rash, urticaria or pruritus occurred in approximately 1.7% of patients. One serum sickness-like reaction (0.03%) was reported among the 3,272 patients treated with Cefaclor prolonged-release during the controlled clinical trials.
Serum sickness-like reactions (erythema multiforme minor, rashes or other skin manifestations accompanied by arthritis/arthralgia, with or without fever) have been reported with cefaclor.
Lymphadenopathy and proteinuria are infrequent, there are no circulating immune complexes and no evidence of sequelae. Occasionally, solitary symptoms may occur, but do not represent a serum sickness-like reaction. Serum sickness-like reactions are apparently due to hypersensitivity and have usually occurred during or following a second (or subsequent) course of therapy with cefaclor. Such reactions have been reported more frequently in children than in adults. Signs and symptoms usually occur a few days after initiation of therapy and usually subside within a few days of cessation of therapy. Antihistamines and corticosteroids appear to enhance resolution of the syndrome. No serious sequelae have been reported.
Haematological and lymphatic systems: Eosinophilia.
Genitourinary: Vaginal moniliasis (2.5%) and vaginitis (1.7%).
The following adverse effects have been reported, but causal relationship is uncertain:
Central nervous system: Headache, dizziness and somnolence. Hepatic: Transient elevations in AST, ALT and alkaline phosphatase. Renal: Transient increase in BUN or creatinine. There have been reports of neurological sequelae including tremor, myoclonia, convulsions, encephalopathy with drugs belonging to the class of cephalosporins. Most cases occurred in patients with renal impairment who received doses that exceeded the recommended dose and resolved following discontinuation of treatment.
Laboratory tests: Transient thrombocytopenia, leucopenia, lymphocytosis, neutropenia and abnormal urinalysis.
In addition to the adverse reactions listed above that have been observed in patients taking Cefaclor prolonged-release tablets, the following have been reported in patients treated with cefaclor:
Erythema multiforme, fever, anaphylaxis (may be more common in patients with a history of penicillin allergy), Stevens-Johnson syndrome, positive direct Coombs' test and genital pruritus. Symptoms of pseudomembranous colitis may appear either during or after antibiotic treatment. Anaphylactoid events may present as solitary symptoms, including angioedema, asthenia, oedema (including face and limbs), dyspnoea, paraesthesias, syncope, orvasodilatation.
Rarely, hypersensitivity symptoms may persist for several months.
The following reactions have been reported rarely in patients treated with cefaclor:
Toxic epidermal necrolysis, reversible interstitial nephritis, hepatic dysfunction, including cholestasis, increased prothrombin time in patients receiving cefaclor and warfarin concomitantly, reversible hyperactivity, agitation, nervousness, insomnia, confusion, hallucinations, hypertonia, aplastic anaemia, agranulocytosis and haemolytic anaemia.
The following adverse reactions have been reported in patients treated with other beta-lactam antibiotics:
Colitis, renal dysfunction and toxic nephropathy.
Several beta-lactam antibiotics have been implicated in triggering seizures, particularly in patients with renal impairment when the dosage was not reduced. If seizures associated with drug therapy should occur, the drug should be discontinued. Anticonvulsant therapy can be given if clinically indicated.
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continues monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme Website: www.mhra.gov.uk/yellowcard.