Mezlocillin (Mezlin)


  • Antibiotic


  • Penicillin


  • Mild to moderate infections (i.e.; lower respiratory, intra-abdominal, urinary tract, uncomplicated gonorrhea, gynecological, skin, septicemia, streptococcal and pseudomonal infections)

  • susceptible strains of H. influenzae, Klebsiella species, Pseudomonas species, Proteus mirabilis, E. coli, Enterobacter species, Streptococcus faecelis, Peptococcus species, Peptostreptococcus species, Bacteriodes species (including B. fragilis), Morganella morganii, Serratia  species, N. gonorrhoeae, P. vulgaris, Providencia rettgeri


  • None


  • Pregnancy category B

  • Use with caution in patients with PCN or cephalosporin allergy (5-10% chance of cross-reactivity)

Adverse Reactions (Side Effects):

  • Hypersensitivity

  • Gastrointestinal: nausea, diarrhea

  • Vaginitis  


  • Administered by IV or IM injection

  • Adults:

    • 200-300mg/kg/day in 4-6 divided doses (usual dose 3gm q4h)

  • Infants (> 1 month old) and Child:

    • 50mg/kg every 4 hours (300mg/kg/day)

  • Neonates:

    • dosed based on age and weight

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