Mezlocillin (sodium salt)

Mezlocillin is a β-lactam antibiotic and derivative of ampicillin .^1,2 It is active against B. fragilis, E. lentum, P. morbillorum, and F. nucleatum (MICs = 8, 4, 2, and 4 µg/ml, respectively).² Mezlocillin (32 µg/ml) is also active against 10 strains of S. faecalis.¹ In vivo, mezlocillin (240 mg/kg) increases survival and reduces bacteremia in a rabbit model of S. faecalis endocarditis. It completely eliminates lung P. morbillorum, E. lentum, and F. nucelatum, but not B. fragilis, in a rabbit model of pulmonary P. morbillorum, E. lentum, F. nucelatum, and B. fragilis infection when administered at a dose of 300 mg/kg.² Formulations containing mezlocillin have been used in the treatment of various bacterial infections.

1.Fass, R.J., and Wright, C.A.Comparative efficacies of mezlocillin and ampicillin alone or in combination with gentamicin in the treatment of Streptococcus faecalis endocarditis in rabbitsAntimicrob. Agents Chemother.25(4)408-410(1983) 2.Chandrasekar, P.H., Rolston, K.V.I., Chokkavelu, C., et al.Comparative efficacy of four antibiotics in anaerobic pulmonary infection. An experimental model in rabbitsChemotherapy30(5)331-336(1984)