Pefloxacin mesylate dihydrate is primarily used as an antibacterial agent in the treatment of various infections. It is effective against a wide range of gram-negative and gram-positive bacteria, making it suitable for treating respiratory tract infections, urinary tract infections, skin and soft tissue infections, and bone and joint infections. Its ability to penetrate tissues deeply allows it to be particularly useful in managing severe or systemic infections. Additionally, it is often employed in cases where other antibiotics have failed due to bacterial resistance. The compound is typically administered intravenously or orally, depending on the severity and type of infection being treated.