<p>Fluoroquinolones, including Moxifloxacin, are associated with an increased risk of tendinitis and tendon rupture in all ages. The risk of developing fluoroquinolone-associated tendinitis and tendon rupture is further increased in older patients usually over 60 years of age, in patients taking corticosteroid drugs, and in patients with kidney, heart or lung transplants. Fluoroquinolones have neuromuscular blocking activity and may exacerbate muscle weakness in persons with myasthenia gravis. Clostridium difficile-associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including Moxifloxacin, and may range in severity from mild diarrhea to fatal colitis.</p>