It is Semi-synthetic broad-spectrum penicillin has strong effect on Pseudomonas aeruginosa, Proteus and Escherichia coli.It is used for the treatment of infections known to be or highly likely to be caused by these bacteria. These include common respiratory infections including sinusitis, bronchitis, and pharyngitis, as well as otitis media. In combination with vancomycin (which provides coverage of ampicillin-resistant pneumococci), it is effective for the treatment of bacterial meningitis. It is also used for gastrointestinal infections caused by consuming contaminated water or food, such as Salmonella, Shigella, and Listeriosis.