[4] The aerobic mold which yielded cephalosporin C was found in the sea near a sewage outfall in Su Siccu, by Cagliari harbour in Sardinia, by the Italian pharmacologist Giuseppe Brotzu in July 1945.

[7] Common adverse drug reactions (ADRs) (≥ 1% of patients) associated with the cephalosporin therapy include: diarrhea, nausea, rash, electrolyte disturbances, and pain and inflammation at injection site.

Infrequent ADRs (0.1–1% of patients) include vomiting, headache, dizziness, oral and vaginal candidiasis, pseudomembranous colitis, superinfection, eosinophilia, nephrotoxicity, neutropenia, thrombocytopenia, and fever.

[10] Hence, it was commonly stated that they are contraindicated in patients with a history of severe, immediate allergic reactions (urticaria, anaphylaxis, interstitial nephritis, etc.)

[11] The contraindication, however, should be viewed in the light of recent epidemiological work suggesting, for many second-generation (or later) cephalosporins, the cross-reactivity rate with penicillin is much lower, having no significantly increased risk of reactivity over the first generation based on the studies examined.

[10][12] The British National Formulary previously issued blanket warnings of 10% cross-reactivity, but, since the September 2008 edition, suggests, in the absence of suitable alternatives, oral cefixime or cefuroxime and injectable cefotaxime, ceftazidime, and ceftriaxone can be used with caution, but the use of cefaclor, cefadroxil, cefalexin, and cefradine should be avoided.

[17] Thus, consumption of alcohol after taking these cephalosporin orally or intravenously is contraindicated, and in severe cases can lead to death.

[19] Cephalosporins are bactericidal and, like other β-lactam antibiotics, disrupt the synthesis of the peptidoglycan layer forming the bacterial cell wall.

Some Morganella morganii, Proteus vulgaris, Providencia rettgeri, Pseudomonas aeruginosa, Serratia marcescens and Klebsiella pneumoniae strains have also developed resistance to cephalosporins to varying degrees.

[citation needed] Gram-negative: Greater than first-generation: HEN Haemophilus influenzae, Enterobacter aerogenes and some Neisseria + the PEcK described above.

They may be particularly useful in treating hospital-acquired infections, although increasing levels of extended-spectrum beta-lactamases are reducing the clinical utility of this class of antibiotics.

They are also able to penetrate the central nervous system, making them useful against meningitis caused by pneumococci, meningococci, H. influenzae, and susceptible E. coli, Klebsiella, and penicillin-resistant N. gonorrhoeae.

[33] Cephalosporin compounds were first isolated from cultures of Acremonium strictum from a sewer in Sardinia in 1948 by Italian scientist Giuseppe Brotzu.

[42] He noticed these cultures produced substances that were effective against Salmonella typhi, the cause of typhoid fever, which had β-lactamase.