I need to have your advice

In fact, I have a question about irregular pulse. Last month, my uncle started to experience some difficulty while breathing. I have brought to our family doctor and he said that his pulse is irregular which gave him difficulty to breathe. He was very desperate on hearing that he has to live with heart problem through all his life. His health can deteriorate at anytime with all these problems. While surfing on the net, I came through a medication, cordarone, which is used in the treatment of irregular pulse and heart problems.
I’ve told my uncle about this medication and he was glad to hear that there is a medication for his illness.
How long will it take to cure his illness?? Does he need the prescription of a doctor??