Obstetrics
Fentanyl is sometimes given intrathecally as part of spinal anesthesia or epidurally for epidural anaesthesia and analgesia. Because of fentanyls high lipid solubility, its effects are more localized than morphine, and some clinicians prefer to use morphine to get a wider spread of analgesia. It is widely used in obstetrical anesthesia because of its short time to action peak (about 5 min. ), the rapid termination of its effect after a single dose, and the occurrence of relative cardiovascular stability. In obstetrics, the dose must be closely regulated in order to prevent large amounts of transfer from mother to fetus. At high doses, the drug may act on the fetus to cause postnatal respiratory distress. For this reason, shorter acting agents such as alfentanyl or remifentanil may be more suitable in the context of inducing general anaesthesia. Pain management
The bioavailability of intranasal fentanyl is about 70–90%, but with some imprecision due to clotted nostrils, pharyngeal swallow, and incorrect administration. For both emergency and palliative use, intranasal fentanyl is available in doses of 50, 100, and 200 µg. In emergency medicine, safe administration of intranasal fentanyl with a low rate of side effects and a promising pain-reducing effect was demonstrated in a prospective observational study in about 900 out-of-hospital patients.In children, intranasal fentanyl is useful for the treatment of moderate and severe pain and is well tolerated. Chronic pain
It is also used in the management of chronic pain including cancer pain. Often, transdermal patches are used.
In contexts of poly-substance use, blood fentanyl concentrations of approximately 7 ng/ml or greater have been associated with fatalities. Over 85% of overdoses involved at least one other drug, and there was no clear correlation showing at which level the mixtures were fatal. The dosages of fatal mixtures varied by over three magnitudes in some cases. This extremely unpredictable volatility with other drugs makes it especially difficult to avoid fatalities.Naloxone can completely or partially reverse an opioid overdose. In July 2014, the Medicines and Healthcare products Regulatory Agency (MHRA) of the UK issued a warning about the potential for life-threatening harm from accidental exposure to transdermal fentanyl patches, particularly in children, 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. In the US, fentanyl and fentanyl analogs caused over 29,000 deaths in 2017, a large increase over the previous four years. Most of the recent increases in fentanyl deaths do not involve prescription fentanyl but are related to illicitly made fentanyl that is being mixed with or sold as heroin. Death from fentanyl overdose continues to be a public health issue of national concern in Canada since September 2015. In 2016, deaths from fentanyl overdoses in the province of British Columbia averaged two persons per day.