Penicillin antibiotic / beta-lactamase inhibitor combinations are used to treat bacterial infections such as sinusitis, pneumonia, and urinary tract infections. They also have other uses, such as treating skin infections. These medications combine a penicillin antibiotic with a beta-lactamase inhibitor that helps prevent bacteria from breaking down the antibiotic, which makes the medication work better. Some of these medications come in oral forms, while others are injectable. Examples include amoxicillin / potassium clavulanate (Augmentin) and piperacillin / tazobactam (Zosyn). These medications help treat the infection effectively.