Ampicillin/sulbactam is a combination of the common penicillin-derived antibiotic ampicillin and sulbactam, an inhibitor of bacterial beta-lactamase. Two different forms of the drug exist. The first, developed in 1987 and marketed in the United States under the tradename Unasyn, is an intravenous antibiotic. The second, an oral form called sultamicillin, is marketed under the trade name Ampictam outside of the United States. Ampicillin/sulbactam is used to treat infections caused by bacteria resistant to beta-lactam antibiotics. Sulbactam blocks the enzyme which breaks down ampicillin and thereby allows ampicillin to attack and kill the bacteria.
|Skeletal formula of ampicillin||Skeletal formula of sulbactam||Skeletal formula of sultamicillin, highliting ampicillin in blue and sulbactam in orange|
Ampicillin/sulbactam is also used when the cause of an infection is not known (empiric therapy). Intra-abdominal infections, skin infections, pneumonia, and gynecologic infections. It is active against a wide range of bacterial groups, including Staphylococcus aureus, Enterobacteriaceae, and anaerobic bacteria. Importantly, it is not active against Pseudomonas aeruginosa and should not be used alone when infection with this organism is suspected or known.