Dicloxacillin sodium USP is a semisynthetic antibiotic substance which resists destruction by the enzyme penicillinase (beta-lactamase). It is monosodium (2S,5R,6R)-6-[3-(2,6-dichlorophenyl)-5-methyl-4- isoxazolecarboxamido]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo [3.2.0]heptane-2-carboxylate monohydrate. Like other β-lactam antibiotics, dicloxacillin acts by inhibiting the synthesis of bacterial cell walls. It inhibits cross-linkage between the linear peptidoglycan polymer chains that make up a major component of the cell wall of Gram-positive bacteria. Dicloxacillin is administered orally via capsule form or powder for reconstitution.

Nafcillin is a beta-lactam antibiotic of penicillin class. As a beta-lactamase-resistant penicillin, it is used to treat infections caused by Gram-positive bacteria, in particular, species of staphylococci that are resistant to other penicillins.

Oxacillin is a penicillin beta-lactam antibiotic used in the treatment of bacterial infections caused by susceptible, usually gram-positive, organisms. The name "penicillin" can either refer to several variants of penicillin available, or to the group of antibiotics derived from the penicillins. Oxacillin has in vitro activity against gram-positive and gram-negative aerobic and anaerobic bacteria. The bactericidal activity of Oxacillin results from the inhibition of cell wall synthesis and is mediated through Oxacillin binding to penicillin binding proteins (PBPs). Oxacillin is stable against hydrolysis by a variety of beta-lactamases, including penicillinases, and cephalosporinases and extended spectrum beta-lactamases. By binding to specific penicillin-binding proteins (PBPs) located inside the bacterial cell wall, Oxacillin inhibits the third and last stage of bacterial cell wall synthesis. Cell lysis is then mediated by bacterial cell wall autolytic enzymes such as autolysins; it is possible that Oxacillin interferes with an autolysin inhibitor. Oxacillin is used in the treatment of resistant staphylococci infections. Oxacillin sodium was marketed under the trade name Bactocill.

Flucloxacillin is an isoxazolyl penicillin of the β-lactam group of antibiotics, which exerts a bactericidal effect upon many Gram-positive organisms including β-lactamase-producing staphylococci and streptococci. While no longer used in the United States, Flucloxacillin is supplied under a variety of trade names in other countries, including Floxapen, Flopen, Staphylex. Floxapen is indicated for the treatment of infections due to sensitive Gram-positive organisms, including β-lactamase-producing staphylococci and streptococci. Typical indications including, skin and soft tissue infections; respiratory tract infections; other infections caused by floxapen-sensitive organisms, like example, osteomyelitis, urinary tract infection, septicaemia, endocarditis. Floxapen is also indicated for use as a prophylactic agent during major surgical procedures when appropriate; for example cardiothoracic and orthopaedic surgery. Flucloxacillin, by its action on the synthesis of the bacterial wall, exerts a bactericidal effect on streptococci except those of group D (Enterococcus faecalis) staphylococci. It is not active against methicillin-resistant staphylococci. There is evidence that the risk of flucloxacillin induced liver injury is increased in subjects carrying the HLA-B*5701 allele. Despite this strong association, only 1 in 500-1000 carriers will develop liver injury. Consequently, the positive predictive value of testing the HLA-B*5701 allele for liver injury is very low (0.12%) and routine screening for this allele is not recommended. Flucloxacillin diffuses well into most tissue. Specifically, active concentrations of flucloxacillin have been recovered in bones: 11.6 mg/L (compact bone) and 15.6 mg/L (spongy bone), with a mean serum level of 8.9 mg/L. Flucloxacillin diffuses in only small proportion into the cerebrospinal fluid of subjects whose meninges are not inflamed. It is also excreted in small quantities in mother's milk. In normal subjects approximately 10% of the flucloxacillin administered is metabolised to penicilloic acid. The elimination half-life of flucloxacillin is in the order of 53 minutes.

Cefazedone is a semisynthetic first-generation cephalosporin with activity against Gram-positive and Gram-negative bacteria. Cefazedone 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. Unlike other cephalosporins cefazedone possesses good activity against gram-positive bacteria

Epihetacillin is a derivative of Hetacillin. Epihetacillin can be obtained from hetacillin by treatment with triethylamine. Epi derivative is inactive. Hetacillin is a penicillin-like, beta-lactam-based antibiotic prodrug used to treat infections, usually from Gram-positive bacteria. Hetacillin itself has no antibacterial activity, but is converted in the body to ampicillin and has actions and uses similar to those of ampicillin. Hetacillin is prepared by reacting ampicillin with acetone. Ampicillin rapidly decomposes because of the intramolecular attack of the side chain amino group on the lactam ring. Hetacillin locks up the offending amino group and prevents the decompolsition Hetacillin, once hydrolyzed to ampicillin (and acetone) binds to the penicillin binding proteins found in susceptible bacteria. This inhibits the third and last stage of bacterial cell wall synthesis. Cell lysis is then mediated by bacterial cell wall autolytic enzymes such as autolysins. Targets below reflect ampicillin targets. Hetacillin is sold under the trade name Hetacin for intramammary injection in veterinary use. Hetacillin was removed from the market for human use when the discovery was made that it is actually cleaved in the gastrointestinal tract to formaldehyde and had no advantages over ampicillin.

Tebipenem pivoxil is an oral carbapenem prodrug that was originated by Wyeth (now Pfizer). It was approved by Pharmaceuticals and Medical Devices Agency of Japan (PMDA) on Apr 22, 2009. It was developed and marketed as Orapenem® by Meiji Seika in Japan. Tebipenem pivoxil is a broad-spectrum orally-administered antibiotic, from the carbapenem subgroup of β-lactam antibiotics. Carbapenems are a class of beta-lactam antibiotics, which act by inhibiting the synthesis of the peptidoglycan layer of bacterial cell walls. It is used to treat otorhinolaryngological infection, otitis media and bacterial pneumonia. Orapenem® is available as granules for oral use, containing 100 mg Tebipenem pivoxil/g granules. According to the weight of children, 4 mg/kg, and twice a day after dinner.

Cefcapene is a semisynthetic third-generation cephalosporin with antibacterial activity. Cefcapene 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.

Cefpirome is a semisynthetic, broad-spectrum, fourth-generation cephalosporin with antibacterial activity. Cefpirome 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. Cefpirome is an injectable extended-spectrum or 'fourth generation' cephalosporin. Its antibacterial activity encompasses many of the pathogens involved in hospital-acquired infections such as Enterobacteriaceae, methicillin-susceptible Staphylococcus aureus, coagulase-negative staphylococci and viridans group streptococci. Cefpirome also has in vitro activity against Streptococcus pneumoniae regardless of penicillin susceptibility. It is stable against most plasmid- and chromosome-mediated beta-lactamases, with the exception of the extended-spectrum plasmid-mediated SHV enzymes. Intravenous cefpirome 2g twice daily has shown clinical efficacy comparable to that of ceftazidime 2g 3 times daily in the treatment of hospitalised patients with moderate to severe infections. Clinical response and bacteriological eradication rates were similar in patients with severe pneumonia or septicaemia treated with either cefpirome or ceftazidime. Cefpirome appeared more effective than ceftazidime in the eradication of bacteria in patients with febrile neutropenia in 1 study; however, clinical response rates were similar in the 2 treatment groups. The tolerability of cefpirome appears similar to that of ceftazidime and other third generation cephalosporins, diarrhoea being the most frequently observed event. Thus, cefpirome is likely to be a valuable extended-spectrum agent for the treatment of severe infections. Cefpirome offers improved coverage against some Gram-positive pathogens and Enterobacteriaceae producing class I beta-lactamases compared with the third generation cephalosporins, although this has yet to be demonstrated in clinical trials.

Bambermycins (flavomycin) is a complex of antibiotics obtained from Streptomyces bambergiensis and Streptomyces ghanaensis used as a food additive for poultry and swine. Inhibitor of the in vitro transglycosylase activities of PBPs. Bambermycins complex consists mainly of moenomycins A and C. Moenomycin A is the prototype for compounds that bind to bacterial peptidoglycan glycosyltransferases (PGTs) and inhibit cell wall biosynthesis