The price of fentanyl transdermal patch varies in different sales areas and is about 50-70 RMB per piece. When used, each patch lasts about 3 days. When fentanyl transdermal patch is used, it is often not effective on the first day. Therefore, if it is used for cancer pain relief, two days after using the first fentanyl transdermal patch, a second patch should be applied. At this time, do not remove the previous patch, and remove the previous patch after a day, so as to ensure the blood concentration of fentanyl in the body and enable cancer pain patients to achieve uninterrupted and continuous pain relief, which is conducive to ensuring the comfort of patients.