CS-834 is a beta-lactam antibiotic of a carbapenem class, developed by the Japanese company Sankyo Co. Ltd. CS-834 is an ester-type prodrug of the active metabolite R-95867. The drug showed potent and well balanced antibacterial activity as well as stability against dehydropeptidase-I. The in vivo efficacy of CS-834 was evaluated in murine systemic infections caused by 16 strains of gram-positive and -negative pathogens. The efficacy of CS-834 was in many cases superior to those of cefteram pivoxil, cefpodoxime proxetil, cefdinir, and cefditoren pivoxil, especially against infections caused by S. aureus, penicillin-resistant S. pneumoniae, E. coli, Citrobacter freundii, and Proteus vulgaris. Pharmacokinetics of CS-834 was evaluated in healthy male volunteers, but no further clinical development of the drug was reported.

Cefditoren pivoxil is a semi-synthetic cephalosporin antibiotic for oral administration. It is a 3rd generation cephalosporin that is FDA approved for the treatment of acute bacterial exacerbation of chronic bronchitis, community acquired pneumonia, infection of skin and/or subcutaneous tissue, and pharyngitis/tonsillitis. Cefditoren is a cephalosporin with antibacterial activity against gram-positive and gram-negative pathogens. The bactericidal activity of cefditoren results from the inhibition of cell wall synthesis via affinity for penicillin-binding proteins (PBPs). Common adverse reactions include diarrhea, nausea and candida vaginitis. Co-administration of a single dose of an antacid which contained both magnesium (800 mg) and aluminum (900 mg) hydroxides or co-administration of a single dose of intravenously administered famotidine (20 mg) reduced the oral absorption of a single 400 mg dose of cefditoren pivoxil administered following a meal. Co-administration of probenecid with cefditoren pivoxil resulted in an increase in the plasma exposure of cefditoren.

Cefetamet pivoxil is an oral third-generation cephalosporin which is hydrolysed to form the active agent, cefetamet. Cefetamet has excellent in vitro activity against the major respiratory pathogens Streptococcus pneumoniae, Haemophilus influenzae, Moraxella (Branhamella) catarrhalis and group A beta-haemolytic streptococci; it is active against beta-lactamase-producing strains of H. influenzae and M. catarrhalis, but has poor activity against penicillin-resistant S. pneumoniae. Cefetamet has marked activity against Neisseria gonorrhoeae and possesses a broad spectrum of activity against Enterobacteriaceae. Both staphylococci and Pseudomonas spp. are resistant to cefetamet. Cefetamet pivoxil has been investigated in the treatment of both upper and lower community-acquired respiratory tract infections and has demonstrated equivalent efficacy to a number of more established agents, namely cefaclor, amoxicillin and cefixime. In complicated urinary tract infections, cefetamet pivoxil showed similar efficacy to cefadroxil, cefaclor and cefuroxime axetil. Cefetamet pivoxil was effective in the treatment of otitis media, pneumonia, pharyngotonsillitis and urinary tract infections in children. Cefetamet is not extensively bound to plasma proteins. Cefetamet has a relatively small apparent volume of distribution consistent with that of other beta-lactam antibiotics. The absorption and disposition of cefetamet in human subpopulations [i.e. children, elderly (< 75 years of age), renal impairment, liver disease and patients taking concomitant drugs] have been studied extensively. Only impaired renal function appears to significantly alter the elimination of this drug. Cefetamet pivoxil exerts its bactericidal action by inhibition the final transpeptidation step of peptidoglycan synthesis in the bacterial cell wall by binding to one or more of the Penicillin-binding Proteins (PBPs).

Cefteram is a semisynthetic cephalosporin formulated for oral administration as the prodrug ester, cefteram pivoxil. The mechanism of action of cefteram is inhibition of bacterial cell wall synthesis. Cefteram exerts its bactericidal activity by strongly binding to penicillin-binding protein (PBP) 3, 1A, and 1Bs. The drug is available in Japan and is used for the treatment of bacterial infections.

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.

Cefditoren pivoxil is a semi-synthetic cephalosporin antibiotic for oral administration. It is a 3rd generation cephalosporin that is FDA approved for the treatment of acute bacterial exacerbation of chronic bronchitis, community acquired pneumonia, infection of skin and/or subcutaneous tissue, and pharyngitis/tonsillitis. Cefditoren is a cephalosporin with antibacterial activity against gram-positive and gram-negative pathogens. The bactericidal activity of cefditoren results from the inhibition of cell wall synthesis via affinity for penicillin-binding proteins (PBPs). Common adverse reactions include diarrhea, nausea and candida vaginitis. Co-administration of a single dose of an antacid which contained both magnesium (800 mg) and aluminum (900 mg) hydroxides or co-administration of a single dose of intravenously administered famotidine (20 mg) reduced the oral absorption of a single 400 mg dose of cefditoren pivoxil administered following a meal. Co-administration of probenecid with cefditoren pivoxil resulted in an increase in the plasma exposure of cefditoren.

Cefditoren pivoxil is a semi-synthetic cephalosporin antibiotic for oral administration. It is a 3rd generation cephalosporin that is FDA approved for the treatment of acute bacterial exacerbation of chronic bronchitis, community acquired pneumonia, infection of skin and/or subcutaneous tissue, and pharyngitis/tonsillitis. Cefditoren is a cephalosporin with antibacterial activity against gram-positive and gram-negative pathogens. The bactericidal activity of cefditoren results from the inhibition of cell wall synthesis via affinity for penicillin-binding proteins (PBPs). Common adverse reactions include diarrhea, nausea and candida vaginitis. Co-administration of a single dose of an antacid which contained both magnesium (800 mg) and aluminum (900 mg) hydroxides or co-administration of a single dose of intravenously administered famotidine (20 mg) reduced the oral absorption of a single 400 mg dose of cefditoren pivoxil administered following a meal. Co-administration of probenecid with cefditoren pivoxil resulted in an increase in the plasma exposure of cefditoren.

Amdinocillin is a novel, semisynthetic penicillin effective against many gram-negative bacteria. The antibacterial activity of amdinocillin is derived from its ability to bind specifically and avidly to Penicillin Binding Protein-2 (PBP 2). Amdinocillin is active alone against many gram-negative organisms. Pseudomonas and non-fermenting gram-negative bacteria, however, are usually resistant. Amdinocillin, in combination with many beta-lactams, exhibits marked synergy against many enterobacteriaceae. No such synergy can be demonstrated for gram-positive organisms or pseudomonas species. Amdinocillin is not beta-lactamase stable. Organisms which produce high levels of plasma-mediated beta-lactamase are resistant to the drug. Used in the treatment of urinary tract infections caused by some strains of E. coli and klebsiella and enterobacter species. Used mainly against Gram negative organisms. Amdinocillin is not available in the United States.