mezlocillin sodium /mezlos″ilin/ , a semisynthetic penicillin antibiotic. 
INDICATIONS: It is prescribed for the treatment of lower respiratory tract, intraabdominal, urinary tract, gynecological, and skin infections and bacterial septicemia caused by susceptible strains of multiple microorganisms. CONTRAINDICATIONS: Hypersensitivity to any of the penicillins prohibits its use. ADVERSE EFFECTS: The most serious adverse effects are anaphylaxis, convulsive seizures, epigastric pain, reduction in blood elements, and elevation in hepatic and renal parameters.
