Fentanyl transdermal patch belongs to the opioid class of central analgesics and has analgesic and sedative properties. It is used clinically to relieve moderate to severe chronic pain. This product is a topical patch, should be applied on the flat skin surface of the torso, if there is hair should be removed, and the site of application should also be cleaned and completely dry before use. Fentanyl transdermal patch can cause loss of appetite, drowsiness, dizziness, nausea, vomiting, dry mouth, constipation, palpitations, dizziness, fatigue, weakness, rash, itching, mental confusion, disorientation, withdrawal symptoms, a feeling of euphoria and other adverse reactions after administration. Note that this product is contraindicated in chronic non-cancer pain under 40 years of age, and should not be used for acute pain or postoperative analgesia. Contraindicated in patients with known sensitivity to fentanyl or to the adhesives in this product. Patients must use the drug under the supervision of a medical professional and strictly follow medical advice.