The only way that medical professionals are able to treat whooping cough is if it is diagnosed within three weeks of the initial infection, in which case, you will be prescribed antibiotics in the hope that it will reduce symptoms and help stop the spread of the infection to others. After that three-week mark, you are no longer contagious and antibiotics will no longer be useful in the reduction of symptoms. At this point, the symptoms will most likely eventually go away on their own as you slowly recover.