MEROPENEM IS A STERILE, PYROGEN-FREE, SYNTHETIC, BROAD-SPECTRUM, CARBAPENEM ANTIBIOTIC FOR INTRAVENOUS ADMINISTRATION. 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 (BETA)-LACTAMASES OF MOST CATEGORIES, BOTH PENICILLINASES AND CEPHALOSPORINASES PRODUCED BY GRAM-POSITIVE AND GRAM-NEGATIVE BACTERIA, WITH THE EXCEPTION OF METALLO-(BETA)-LACTAMASES. MEROPENEM SHOULD NOT BE USED TO TREAT METHICILLIN-RESISTANT STAPHYLOCOCCI. IN VITRO TESTS SHOW MEROPENEM TO ACT SYNERGISTICALLY WITH AMINOGLYCOSIDE ANTIBIOTICS.