Meropenem (generic name: meropenem hydrate) is a carbapenem antibiotic for injection showing a strong antibacterial activity to a wide range of bacteria strains from Gram-positive bacteria, Gram-negative bacteria to anaerobic bacteria. It is used as single agent therapy for the treatment of the following infections: complicated skin and skin structure infections due to Staphylococcus aureus (b-lactamase and non-b-lactamase producing, methicillin-susceptible isolates only), Streptococcus pyogenes, Streptococcus agalactiae, viridans group streptococci. This drug also used in case of Intra-abdominal Infections for the treatment complicated appendicitis and peritonitis caused by viridans group streptococci, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacteroides fragilis, B. thetaiotaomicron, and Peptostreptococcus species. In addition is used the treatment of bacterial meningitis caused by Streptococcus pneumoniae, Haemophilus influenzae (b-lactamase and non-b-lactamase-producing isolates), and Neisseria meningitides. The bactericidal activity of meropenem results from the inhibition of cell wall synthesis. Meropenem readily penetrates the cell wall of most Gram-positive and Gram-negative bacteria to reach penicillin-binding-protein (PBP) targets. Its strongest affinities are toward PBPs 2, 3 and 4 of Escherichia coli and Pseudomonas aeruginosa; and PBPs 1, 2 and 4 of Staphylococcus aureus. Meropenem has significant stability to hydrolysis by β-lactamases, both penicillinases and cephalosporinases produced by Gram-positive and Gram-negative bacteria. Meropenem should not be used to treat methicillin-resistant Staphylococcus aureus (MRSA) or methicillin-resistant Staphylococcus epidermidis (MRSE). Meropenem product with such superior effectiveness and safety has been approved for marketing by 100 countries or more in the world (as of March 2004) since its first launch in Italy in 1994.

Tazobactam is a beta-lactamase inhibitor, which was approved by FDA for the treatment of wide range of bacterial infections either in combination with piperacillin (Zosyn) or with ceftolozane (Zerbaxa).

PRIMAXIN® is a combination of cilastatin and imipenem. Cilastatin is a specific and reversible renal dehydropeptidase-I inhibitor. Imipenem is a penem antibacterial drug. Since the antibiotic, imipenem, is hydrolyzed by dehydropeptidase-I, which resides in the brush border of the renal tubule, cilastatin is administered with imipenem to block the metabolism and thus the inactivation of imipenem so that antibacterial levels of imipenem can be attained in the urine. However, cilastatin in and of itself does not have any antibacterial activity. It also prevents the metabolism of leukotriene D4 to leukotriene E4 through the inhibition of leukotriene D4 dipeptidase.

Imipenem is a beta-lactam antibiotic belongings to the subgroup of carbapenems. Imipenem has a broad spectrum of activity against aerobic and anaerobic Gram positive as well as Gram negative bacteria. It is particularly important for its activity against Pseudomonas aeruginosa and the Enterococcus species. Imipenem is rapidly degraded by the renal enzyme dehydropeptidase when administered alone, and is always co-administered with cilastatin to prevent this inactivation. The bactericidal activity of imipenem results from the inhibition of cell wall synthesis. Its greatest affinity is for penicillin binding proteins (PBPs) 1A, 1B, 2, 4, 5 and 6 of Escherichia coli, and 1A, 1B, 2, 4 and 5 of Pseudomonas aeruginosa. The lethal effect is related to binding to PBP 2 and PBP 1B. Imipenem is marketed under the brand name Primaxin. PRIMAXIN I.M. (Imipenem and Cilastatin for Injectable Suspension) is a formulation of imipenem (a thienamycin antibiotic) and cilastatin sodium (the inhibitor of the renal dipeptidase, dehydropeptidase I). PRIMAXIN I.M. is a potent broad spectrum antibacterial agent for intramuscular administration.