Sultacillin Mechanism of Action

Pharmacology: Pharmacodynamics: Biochemical studies with cell-free bacterial systems have shown sulbactam to be an irreversible inhibitor of most important beta-lactamases that occur in penicillin resistant organism. It possesses significant antibacterial activity only against Neisseriaceae, Acinetobacter calcoaceticus, Bacteroides sp., Branhamella catarrhalis and Pseudomonas cepacia. The potential for sulbactam sodium's preventing the destruction of penicillins and cephalosporins by resistant organism was confirmed in whole-organism studies using resistant strains, in which sulbactam sodium exhibited marked synergistic effects with penicillin and cephalosporins. Since sulbactam also binds to some penicillin-binding proteins, some sensitive strains are rendered more susceptible to the combination than to the beta-lactam antibiotics alone.
The bactericidal component of the combination is ampicillin which, like benzyl penicillin, acts against sensitive organism during the stage of active multiplication by the inhibition of biosynthesis of cell-wall mucopeptide. Ampicillin sodium/Sulbactam sodium IM/IV is effective against a wide range of Gram-positive and Gram-negative bacteria including: Staphylococcus aureus and epidermidis (including penicillin-resistant and some methicillin-resistant strains); Streptococcus pneumoniae, Streptococcus faecalis and other Streptococcus species; Haemophilus influenzae and parainfluenzae (both beta-lactamase positive and negative strains); Branhamella catarrhalis, anaerobes, including Bacteroides fragilis and related species; Escherichia coli, Klebsiella species, Proteus species (both indole-positive and indole-negative), Morganelli morganii, Citrobacter species, Enterobacter species, Neisseria meningitis and Neisseria gonorrheae.
Pharmacokinetics: Ampicillin sodium/Sulbactam sodium IM/IV diffuses readily into most body tissues and fluids in the human. Penetration into brain and spinal fluid is low except when meninges are inflamed. High concentrations of ampicillin and sulbactam are achieved in the blood following intravenous or intramuscular administration and both components have a half life of approximately 1 hour. Most of the Ampicillin sodium/Sulbactam sodium IM/IV is excreted unchanged in the urine.