The adverse effects associated with cephalosporins are broadly similar to those described for penicillins. The most common are hypersensitivity reactions, including skin rashes, urticaria, eosinophilia, fever, reactions resembling serum sickness and anaphylaxis.
There may be positive response to the Coomb's test although hemolytic anemia rarely occurs. Neutropenia and thrombocytopenia have occasionally been reported. Agranulocytosis has been associated rarely with some cephalosporins. Bleeding complications related to hypothrombinaemia and/or platelet dysfunction have occurred especially with cephalosporins and cephamycins having an N-methylthiotetrazole side chain, including cefamandole, cefbuperazone, cefmenoxime, cefmetazole, cefonicid, cefoperazone, ceforanide, cefotetan, cefpiramide and latamoxef. The presence of methylthiadiazolethiol side-chain, as in cefazolin, or an N-methylthiotraizine ring, as in ceftriaxone, might also be associated with such bleeding disorders.
Transient increase in liver enzyme values has been reported. Hepatitis and cholestatic jaundice have occurred rarely with some cephalosporins.
Convulsions and other signs of CNS toxicity have been associated with high doses, especially in patients with severe renal impairment.
Gastrointestinal adverse effects such as nausea, vomiting and diarrhea have been reported rarely. Prolonged use may result in overgrowth of non-susceptible organisms and, as with other broad-spectrum antibiotics, pseudomembranous colitis may develop.
There may be pain at the injection site following intramuscular use, and thrombophlebitis has occurred on intravenous infusion of cephalosporins.