The drug you're referring to is likely fentanyl. Fentanyl can be administered transdermally for chronic pain management through patches, but if given intravenously (IV) too quickly or in high doses, it can lead to a side effect known as chest wall rigidity, which can be a serious and life-threatening complication. It's important for healthcare professionals to be aware of this potential side effect when using fentanyl IV and to administer it carefully and in controlled doses
Hope you understand