my dose is 1 to 2 tabs three times a day (tabs are 10 mg each). I took two and felt a little bit of chest pain. I went to emergency clinic and all was well. I read all the side effects of slow breathing or death, i would just like to know how much is dangerous.

I had cancer and my right kidney was removed. I have recovered but I have servere arthritis in my knee's and methodone was percribed because it dose not contain tylenol which would damage my remaining kidney. So i just wanted to know how much is dangerous?