My mother uses Fentanyl patch for pain. It has 50mcg, 75mcg, and 100mcg depending on his level of pain. It stays for 3 days, and then replace with a new one. She used to have vicdin for pain, but it upset her stomach. After we switch to Fentanyl patch, she does not have stomach problem any more. However, every pain killer has some side effects, including nausea, dizzy, constipation etc. So she is taking the stool softner and anti-nausea medicines as well.