Quinolones are a class of broad-spectrum antibiotics that inhibit bacterial DNA gyrase and topoisomerase IV, enzymes essential for DNA replication and transcription. They are important in clinical practice for treating a variety of infections, including urinary tract and respiratory tract infections, especially when resistance to other antibiotics is a concern. A key clinical consideration is their association with tendonitis and tendon rupture, particularly in older adults or those on corticosteroids.