Fentanyl
Adverse effects
Fentanyl's most common side-effects (more than 10% of patients) include diarrhea, nausea, constipation, dry mouth, somnolence, confusion, asthenia (weakness), sweating, and less frequently (3 to 10% of patients) abdominal pain, headache, fatigue, anorexia and weight loss, dizziness, nervousness, hallucinations, anxiety, depression, flu-like symptoms, dyspepsia (indigestion), dyspnea (shortness of breath), hypoventilation, apnea, and urinary retention. Fentanyl use has also been associated with aphasia.[6]
Despite being a more potent analgesic, fentanyl tends to induce less nausea, as well as less histamine-mediated itching, in relation to morphine.[33]
Fentanyl may produce more prolonged respiratory depression than other opioid analgesics.[34][35][36][37][38][39][40] In 2006 the U.S. Food and Drug Administration (FDA) began investigating several respiratory deaths, but doctors in the United Kingdom were not warned of the risks with fentanyl until September 2008.[41] The FDA reported in April 2012 that young children had died or become seriously ill from accidental exposure to a fentanyl skin patch.[42]
The precise reason for sudden respiratory depression is unclear, but there are several hypotheses:
• Saturation of the body fat compartment in patients with rapid and profound body fat loss (patients with cancer, cardiac or infection-induced cachexia can lose 80% of their body fat).
• Early carbon dioxide retention causing cutaneous vasodilatation (releasing more fentanyl), together with acidosis, which reduces protein binding of fentanyl, releasing yet more fentanyl.
• Reduced sedation, losing a useful early warning sign of opioid toxicity and resulting in levels closer to respiratory-depressant levels.
Fentanyl has a therapeutic index of 270.[43]
Overdoses and fatalities
In July 2014, the Medicines and Healthcare Products Regulatory Agency (MHRA) issued a warning about the potential for life-threatening harm from accidental exposure to transdermal fentanyl patches, particularly in children,[44] and advised that they should be folded, with the adhesive side in, before being discarded. The patches should be kept away from children, who are most at risk from fentanyl overdose.[45] Musician Prince died of an accidental overdose of fentanyl in April 2016.[46]
https://en.wikipedia.org/wiki/Fentanyl
Imo - Prince at 112 lbs was very vulnerable to OD...
