I have a throbbing pain in my achilles and my calf muscle remains in a constant tight state. what is this and what is the treatment?

Avelox : Is a floroquinolone antibiotic with a possible side effect of Achilles' tendon rupture. So caution must be had with Achilles' tendon. Having said that you may be experiencing a simple cramp or even possibly a clot. A cramp would not be serious though it can be painful. A clot needs to be ruled out. I would advise against running or excercising so as not to tear the tendon....

Strain: Can be an Achilles strain but at times this can be a warning of possible Achilles partial tearing or pending tear with further stressful activities. Rest hear stretch NSAIDs right now. If does not subside may need immobilization with boot.