Unasyn (generic: ampicillin/sulbactam) is a prescription medication used to treat bacteria that cause infections, including those of the skin, stomach, and women’s reproductive system. It is a single injection containing 2 medications, ampicillin and sulbactam.

Ampicillin belongs to a group of drugs called penicillin antibiotics, which help stop the growth of bacteria. Sulbactam belongs to a group of drugs called beta lactamase inhibitors, which work by preventing bacteria from destroying ampicillin.

This medication is available in an injectable form to be given directly into a vein (IV) or muscle (IM) by a healthcare professional.

Common side effects of Unasyn include diarrhea, rash, and pain at site of injection.