Phenaridine

Phenaridine (2,5-Dimethylfentanyl) is an opioid analgesic that is an analogue of fentanyl. It was developed in the 1970s, and is used for surgical anasthesia. Phenaridine has similar effects to fentanyl. It is slightly less potent than fentanyl in rats. Side effects of fentanyl analogues are similar to those of fentanyl itself, which include itching, nausea and potentially serious respiratory depression which can be life-threatening.