Fentanyl, which is sold under “Duragesic”, is an opioid pain medication “used to treat moderate to severe chronic pain around the clock.” This treatment is available as a transdermal patch, a tablet, nasal spray, or as an injection. As for Fentanyl transdermal patch, it is mainly used to treat chronic pain when other pain treatments such as non-opioid pain medicines do not treat one’s pain well enough or they cannot tolerate them. According to healthline.com, “Fentanyl works in your brain to change how your body feels and responds to pain”. Bear in mind, though, that these transdermal patches can cause drowsiness. Therefore, you need to avoid driving or doing any other activity that requires alertness until you know how this medicine affects you. Besides, Fentanyl can also cause other side effects such as nausea, dizziness, constipation, headache, and trouble sleeping- All of which may go away within a few days. However, if you experience any of the following side effects, you must call a doctor right away: Serious breathing problems, severely low blood pressure, or addiction when you stop using this drug. Based on the information posted on healthline.com, Fentanyl can lead to opioid withdrawal syndrome in a newborn, if their mother uses this drug for a long time during pregnancy. Needless to say this side effect can be life-threatening for the baby.