Ceftizoxime is a semisynthetic cephalosporin antibiotic, which can be administered intravenously or intramuscularly. It was sold under brand name, cefizox, but was removed from the US Market in 2007. Cefizox was used to treat different infections, such as lower respiratory tract infections caused by Klebsiella spp.; Proteus mirabilis; Escherichia coli; Haemophilus influenza; urinary tract Infections caused by Staphylococcus aureus (penicillinase¬ and nonpenicillinase¬producing); Escherichia coli; Pseudomonas spp. Also for treatment of gonorrhea including uncomplicated cervical and urethral gonorrhea caused by Neisseria gonorrhoeae; pelvic inflammatory disease caused by Neisseria gonorrhoeae, Escherichia coli or Streptococcus agalactiae; meningitis caused by Haemophilus influenza. In addition, some others infections. Cefizox has also been used successfully in the treatment of a limited number of pediatric and adult cases of meningitis caused by Streptococcus pneumoniae. Infections caused by aerobic gram ¬negative and by mixtures of organisms resistant to other cephalosporins, aminoglycosides, or penicillins have responded to treatment with Cefizox. The bactericidal action of ceftizoxime results from inhibition of the third and last stage of bacterial cell wall synthesis. Bacterial cell wall autolytic enzymes such as autolysins then mediate cell lysis; it is possible that ceftizoxime interferes with an autolysin inhibitor. Ceftizoxime is highly resistant to a broad spectrum of beta -lactamases (penicillinase and cephalosporinase), including Richmond types II, III, TEM, IV, produced by both aerobic and anaerobic gram - positive and gram - negative organisms and I.

Netilmicin is a semisynthetic, water soluble antibiotic of the aminoglycoside group, produced by the fermentation of Micromonospora inyoensis, a species of actinomycete. Aminoglycosides are useful primarily in infections involving aerobic, Gram-negative bacteria, such as Pseudomonas, Acinetobacter, and Enterobacter. It is active at low concentrations against a wide variety of pathogenic bacteria including Escherichia coli, bacteria of the Klebsiella-Enterobacter-Serratia group, Citrobacter sp., Proteus sp. (indole-positive and indole-negative), including Proteus mirabilis, P. morganii, P. rettgrei, P. vulgaris, Pseudomonas aeruginosa and Neisseria gonorrhoea. Netilmicin is also active in vitro against isolates of Hemophilus influenzae, Salmonella sp., Shigella sp. and against penicillinase and non-penicillinase-producing Staphylococcus including methicillin-resistant strains. Some strains of Providencia sp., Acinetobacter sp. and Aeromonas sp. are also sensitive to netilmicin. Many strains of the above organisms which are found to be resistant to other aminoglycosides, such as kanamycin, gentamicin, tobramycin and sisomicin, are susceptible to netilmicin in vitro. Occasionally, strains have been identified which are resistant to amikacin but susceptible to netilmicin. The combination of netilmicin and penicillin G has a synergistic bactericidal effect against most strains of Streptococcus faecalis (enterococcus). The combined effect of netilmicin and carbenicillin or ticarcillin is synergistic for many strains of Pseudomonas aeruginosa. In addition, many isolates of Serratia, which are resistant to multiple antibiotics, are inhibited by synergistic combinations of netilmicin with carbenicillin, azlocillin, mezlocillin, cefamandole, cefotaxime or moxalactam. Netilmicin "irreversibly" binds to specific 30S-subunit proteins and 16S rRNA. Specifically netilmicin binds to four nucleotides of 16S rRNA and a single amino acid of protein S12. This interferes with decoding site in the vicinity of nucleotide 1400 in 16S rRNA of 30S subunit. This region interacts with the wobble base in the anticodon of tRNA. This leads to interference with the initiation complex, misreading of mRNA so incorrect amino acids are inserted into the polypeptide leading to nonfunctional or toxic peptides and the breakup of polysomes into nonfunctional monosomes, leaving the bacterium unable to synthesize proteins vital to its growth.

Azlocillin is a semisynthetic penicillin with broad spectrum of anti-bacterial action. The drug is effective against gram-negative and gram-positive infections and acts by inhibition of penicillin-binding protein (PBP)-dependent bacterial cell wall synthesis. Azlocillin was marketed in the USA under the name Azlin (sodium salt), however, its approval was discontinued.

Cefoperazone (marketed under the name Cefobid) is a third-generation cephalosporin antibiotic. Cefoperazone has a broad spectrum of activity: Respiratory Tract Infections caused by S. pneumoniae, H. influenzae, S. aureus (penicillinase and non-penicillinase producing strains), S. pyogenes (Group A beta-hemolytic streptococci), P. aeruginosa, Klebsiella pneumoniae, E. coli, Proteus mirabilis, and Enterobacter species. Peritonitis and Other Intra-abdominal Infections caused by E. coli, P. aeruginosa, and anaerobic gram-negative bacilli (including Bacteroides fragilis). Bacterial Septicemia caused by S. pneumoniae, S. agalactiae, S. aureus, Pseudomonas aeruginosa, E. coli, Klebsiella spp., Klebsiella pneumoniae, Proteus species (indole-positive and indole-negative), Clostridium spp. and anaerobic gram-positive cocci. Infections of the Skin and Skin Structures caused by S. aureus (penicillinase and non-penicillinase producing strains), S. pyogenes, and P. aeruginosa. Pelvic Inflammatory Disease, Endometritis, and Other Infections of the Female Genital Tract caused by N. gonorrhoeae, S. epidermidis, S. agalactiae, E. coli, Clostridium spp., Bacteroides species (including Bacteroides fragilis), and anaerobic gram-positive cocci. Cefobid has no activity against Chlamydia trachomatis. Therefore, when Cefobid is used in the treatment of patients with pelvic inflammatory disease and C. trachomatis is one of the suspected pathogens, appropriate anti-chlamydial coverage should be added. Urinary Tract Infections caused by Escherichia coli and Pseudomonas aeruginosa. Cefoperazone, a third-generation cephalosporin, interferes with cell wall synthesis by binding to the penicillin-binding proteins (PBPs), thus preventing cross-linking of nascent peptidoglycan. Cefoperazone is stable to penicillinases and has a high degree of stability to many beta-lactamases produced by gram-negative bacteria. When tested in vitro, cefoperazone has demonstrated synergistic interactions with aminoglycosides against gram-negative bacilli. As with all cephalosporins, hypersensitivity manifested by skin reactions or drug fever. Reversible neutropenia may occur with prolonged administration. Diarrhea or loose stools has been reported also.

Cefotaxime sodium is a semisynthetic, broad spectrum cephalosporin antibiotic for parenteral administration. It’s a 3rd Generation Cephalosporin that is FDA approved for the treatment of lower respiratory tract infections, genitourinary infections, gynecologic infections, bacteremia/septicemia, skin and skin structure infections, intra-abdominal infections, bone and/or joint infections and central nervous system infections. The bactericidal activity of cefotaxime sodium results from inhibition of cell wall synthesis. Cefotaxime sodium has in vitro activity against a wide range of gram-positive and gram-negative organisms. Cefotaxime sodium has a high degree of stability in the presence of ß-lactamases, both penicillinases and cephalosporinases, of gram-negative and gram-positive bacteria. Increased nephrotoxicity has been reported following concomitant administration of cephalosporins and aminoglycoside antibiotics. Common adverse reactions include injection site pain, injection site phlebitis, rash, diarrhea, vomiting. Increased nephrotoxicity has been reported following concomitant administration of cephalosporins and aminoglycoside antibiotics.

Sulfadoxine is an antimalarial agent which, together with pyrimethamine, composes an FDA-approved drug, Fansidar. Sulfadoxine acts by inhibiting dihydropteroate synthase; it crosses the blood-brain barrier and achieves 30% to 60% of the plasma concentration.

Moxalactam (latamoxef) is a new synthetic oxa-beta-lactam antibiotic administered intravenously or intramuscularly. It has a broad spectrum of activity against Gram-positive and Gram-negative aerobic and anaerobic bacteria, is particularly active against Enterobacteriaceae and is resistant to hydrolysis by beta-lactamases. Moxalactam has moderate activity against Pseudomonas aeruginosa, but on the basis of present evidence can not be recommended as sole antibiotic treatment of known or suspected pseudomonal infections. Like the related compounds, the cephalosporins, moxalactam is effective in the treatment of complicated urinary tract infections and lower respiratory tract infections caused by Gram-negative bacilli. Latamoxef works by inhibiting bacterial cell wall biosynthesis. Latamoxef is primarily indicated in conditions like Bone and joint infection, GI infections, Gynecological infections, Meningitis, Respiratory tract infections, Septicaemia, Skin infections, Soft tissue infections, UTI. Latamoxef is no longer available in the United States.

Bayer developed MEZLOCILLIN (previously known as BAYPEN); it is a semisynthetic ampicillin-derived penicillin. Mezlocillin is a penicillin beta-lactam antibiotic used in the treatment of bacterial infections caused by susceptible, usually gram-positive, organisms. The bactericidal activity of mezlocillin results from the inhibition of cell wall synthesis and is mediated through mezlocillin binding to penicillin binding proteins (PBPs). Mezlocillin is stable against hydrolysis by a variety of beta-lactamases, including penicillinases and cephalosporinases and extended spectrum beta-lactamases. Mezlocillin was poorly absorbed orally and was given either intramuscularly or intravenously. This drug was discontinued in the U.S.

Bacampicillin is a penicillin antibiotic. It is a prodrug of ampicillin with improved oral bioavailability. It exerts bactericidal activity via inhibition of bacterial cell wall synthesis by binding one or more of the penicillin binding proteins (PBPs). Spectrobid is used to treat bacterial infections such as tonsillitis, pneumonia (lung infection), bronchitis (inflammation of airway), urinary tract infections, gonorrhea, and infections of the skin. Adverse effects are: anemia, thrombocytopenia, neutropenia, agranulocytosis, seizures, nephrotoxicity, Jarisch-Herxheimer Reaction (fever, chills, sweating, tachycardia, hyperventilation, flushing, and myalgia). Drug interactions: Contraceptives - decreased contraceptive effectiveness; Live Typhoid Vaccine - decreased immunological response to the typhoid vaccine; Probenecid - increased bacampicillin levels.

Sisomicin is a new broad-spectrum aminoglycoside most closely related structurally to gentamicin C1a. In vitro and in experimental infections, sisomicin has been found to be more potent than or nearly as potent as the most active of the other available aminoglycosides. Although susceptible to many (but not all) aminoglycoside-inactivating enzymes, sisomicin is active against many microorganisms that are resistant to other aminoglycosides by nonenzymatic mechanisms. Sisomicin has been shown to interact synergistically with various beta-lactam antibiotics against enterococci, staphylocicci, Enterobacteriaceae, and nonfermentative gram-negative bacilli. The pharmacokinetics and toxicity of sisomicin in humans appear to be similar to those of gentamicin, despite earlier reports of greater acute toxicity in animals. Sisomicin binds to 30s and 50s ribosomal subunits of susceptible bacteria disrupting protein synthesis, thus rendering the bacterial cell membrane defective.