You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is A patient is having a malignancy and has been suffering from severe pain. Which of the following opioid analgesics can be used as transdermal patch for alletion of pain in him? and explain in detail?
(Ref: KDT 6/e p459) Fentanyl can be used as a transdermal patch for prolonged treatment of cancer associated pain.