Fentanyl physiological effects

The major physiological effects of fentanyl are euphoria, drowsiness, respiratory depression, decreased gastrointestinal mobility, nausea, and muscular rigidity. People build up a tolerance to fentanyl the more they use it, causing them to need more to obtain the same effects they once received from a smaller dose. The high of fentanyl can last 10-72 hours, depending on the ingestion method, the fentanyl derivative used, and the amount taken. 

Fentanyl, a synthetic chemical compound, was discovered to be about 100 times as potent as morphine or heroin. Its chemical structure shown in Fig. 17.11 indicates that it can also be classified as an alkaloid. This compound has been widely used as an anesthetic in surgical procedures, as the physiological effects are much shorter-acting than morphine. And it gives a high like heroin, though short-lived. 

Albrecht M, Henke J, Tacke S, Marker M, Guth B (2014) Effects of isoflurane, ketamine-xylazine and a combination of medetomidine, midazolam and fentanyl on physiological variables continuously measured by telemetry in Wistar rats. BMC Vet Res 10 198... 

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