Cephapirin is a first-generation cephalosporin. Cephapirin has been indicated for the treatment of infections when caused by susceptible strains in respiratory, genitourinary, gastrointestinal, skin and soft tissue, bone and joint infections, septicemia; treatment of susceptible gram-positive bacilli and cocci (never enterococcus); some gram-negative bacilli including E. coli, Proteus, and Klebsiella may be susceptible. Cephapirin is used in veterinary as an intra-uterine antibiotic infusion for the treatment of subacute and chronic endometritis in cows and repeat breeders.

Cephradine is a semisynthetic cephalosporin antibiotic. Cephradine is active against the following organisms in vitro: Group A beta-hemolytic streptococci; Staphylococci, including coagulase-positive, coagulase-negative, and penicillinase-producing strains; Streptococcus pneumoniae (formerly Diplococcus pneumoniae); Escherichia coli; Proteus mirabilis; Klebsiella species; Hemophilus influenza. It works by stopping the growth of bacteria. It is used to treat a wide variety of bacterial infections (e.g., skin, ear, respiratory and urinary tract infections). Pseudomembranous colitis has been reported in patients receiving cephradine both orally and intravenously. Diarrhea generally starts 1 to 16 days after starting cephradine therapy. Gastrointestinal side effects have included nausea, vomiting. Hypersensitivity reactions have included rash, urticaria, pruritus, and joint pain. Bacteriostats may interfere with the bactericidal action of cephalosporins in acute infection; other agents, e.g., aminoglycosides, colistin, polymyxins, vancomycin, may increase the possibility of nephrotoxicity.

Cephaloglycin, first oral cephalosporin, was introduced in 1965, but is no longer in common use. It is an orally absorbed derivative of cephalosporin C. Cephaloglycin binds to and inactivates penicillin-binding proteins (PBPs) located on the inner membrane of the bacterial cell wall. PBPs are enzymes involved in the terminal stages of assembling the bacterial cell wall and in reshaping the cell wall during growth and division. Inactivation of PBPs interferes with the cross-linkage of peptidoglycan chains necessary for bacterial cell wall strength and rigidity. This results in the weakening of the bacterial cell wall and causes cell lysis.

Geocillin, a trade name is the sodium salt of the indanyl ester of carbenicillin disodium, which used to treat acute and chronic infections of the upper and lower urinary tract and in asymptomatic bacteriuria due to susceptible strains of bacteria. In addition, Geocillin was also indicated in the treatment of prostatitis due to susceptible strains of the following organisms: Escherichia coli; Enterococcus (S. faecalis); Proteus mirabilis; Enterobacter sp. Free carbenicillin is the predominant pharmacologically active fraction of Geocillin. After absorption, Geocillin is rapidly converted to carbenicillin by hydrolysis of the ester linkage. Carbenicillin exerts its antibacterial activity by interference with final cell wall synthesis of susceptible bacteria. Penicillins acylate the penicillin-sensitive transpeptidase C-terminal domain by opening the lactam ring. This inactivation of the enzyme prevents the formation of a cross-link of two linear peptidoglycan strands, inhibiting the third and last stage of bacterial cell wall synthesis. In 2008 Pfizer has decided to discontinue the manufacturing of Geocillin (carbenicillin indanyl sodium)

Cloxacillin is a derivative of penicillin for the treatment of broad spectrum of bacterial infections. The drug exerts its action by inhiiting bacterial beta-lactamase (penicillin-binding proteins).

Cephalothin is a first generation, semisynthetic analogue of natural cephalosporin antibiotic. The in-vitro bactericidal action of Cephalothin results from inhibition of cell-wall synthesis. In general, Cephalothin has higher activity against Gram positive than Gram negative organisms. Cephalothin is primarily indicated in conditions like bone and joint infection, genitourinary tract infections, respiratory tract infections, soft tissue and skin infections and others. The severe or irreversible adverse effects of Cephalothin, which give rise to further complications, include nephrotoxicity, hemolytic anemia. Cephalothin produces potentially life-threatening effects, which include anaphylaxis, serum sickness syndrome. The symptomatic adverse reactions produced by Cephalothin are: rashes, urticaria, allergic reactions, thrombophlebitis, pain at injection site. Co-administration of diuretics, such as furanthril, ethacrynic acid and nephrotoxic antibiotics may increase the risk of renal damage. Reciprocal inactivation could be observed during in vitro mixing of Cephalothin with aminoglycosides.

Pheneticillin (phenoxyethylpenicillin) is an oral penicillin used for the treatment of upper respiratory tract infections; lower respiratory tract infections; skin and soft tissue infections. Pheneticillin inhibits the synthesis of the cell wall by inhibiting the penicillin binding proteins (PBPs) function. It is well absorbed from the gastrointestinal tract. It reaches the pleural and peritoneal cavities but doesn’t cross the blood-brain barrier. Diarrhea has sometimes occurred with therapeutic doses in man.

Cefovecin is a third generation cephalosporin with a broad-spectrum of activity against Gram-positive and Gram-negative bacteria. Cefovecin differs from other cephalosporins in that it is highly protein bound and has a long duration of activity. As with all cephalosporins, the bactericidal action of cefovecin results from the inhibition of bacterial cell wall synthesis through binding to the penicillin-binding proteins (PBPs). It is indicated for the treatment of skin infections secondary superficial pyoderma, abscesses and wounds. Some gastrointestinal adverse effects like vomiting, anorexia or diarrhea were observed.

Ritipenem (FCE 22101), a penem antibiotic, penicillin binding protein inhibitor, is potent against both gram-positive and -negative bacteria, and its acetoxymethyl ester (FCE 22891; ritipenem-acoxil) is orally available. Ritipenem is manufactured by Tanabe Seiyaku in the ritipenem acoxil prodrug form, which can be taken orally. It is not FDA approved in the United States.

Lenampicillin is a prodrug of ampicillin that inhibits bacterial penicillin binding proteins (transpeptidase) and thus is effective against a wide range of bacterial infections. The drug was developed and marketed in Japan (Takacillin, Varacillin), however its current marketing status is unknown and supposed to be discontinued.