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.

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.

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.

Ticarcillin (also known as Ticar) is a semisynthetic antibiotic with a broad spectrum of bactericidal activity against many gram-positive and gram-negative aerobic and anaerobic bacteria. Ticarcillin is not absorbed orally; therefore, it must be given intravenously or intramuscularly. Ticarcillin's antibiotic properties arise from its ability to prevent cross-linking of peptidoglycan during cell wall synthesis when the bacteria tries to divide, causing death. Usage of ticar was discontinued.

Ticarcillin (also known as Ticar) is a semisynthetic antibiotic with a broad spectrum of bactericidal activity against many gram-positive and gram-negative aerobic and anaerobic bacteria. Ticarcillin is not absorbed orally; therefore, it must be given intravenously or intramuscularly. Ticarcillin's antibiotic properties arise from its ability to prevent cross-linking of peptidoglycan during cell wall synthesis when the bacteria tries to divide, causing death. Usage of ticar was discontinued.

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)

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)

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)