What Causes Rashes On Arms And Legs After Taking Quadtab?

Hi, I started taking quadtab today based on the prescription of my pulmonologist. She said the number if tablets to take is based on weight. So I took 4 quadtab before breakfast. Is there no overdose ? Also I have rashes in my arms and legs when I started using the medicine and I even have difficulty in breathing. Should I stop quadtab right away ?