hello. i am taking quadtab medicine now for a week, i have finished taking the med for 6 mos therapy 2 years ago and already healed. now, i have a hard cough almost 3 weeks already and trying to take other anti cough medicine but no effect, so, i take the quadtab even without prescription of the doctor since this already prescribed by my doctor before, is it ok Doc to take the tab just to cure my cough