Penem antibiotics are used to treat various bacterial infections, including serious skin infections and stomach infections. Some also have other uses, such as treating complicated urinary tract infections, bacterial meningitis, and pneumonia. These antibiotics work by killing bacteria and stopping their growth. Penem antibiotics are usually given as injections. Examples include ertapenem (Invanz) and meropenem (Merrem). These medications are powerful options for fighting serious infections and are typically administered in a hospital setting.