Side effects of fentanyl analogs are similar to those of fentanyl itself, which include itching, nausea and potentially serious respiratory depression, which can be life-threatening. Fentanyl analogs have killed hundreds of people throughout Europe and the former Soviet republics since the most recent resurgence in use began in Estonia in the early 2000s, and novel derivatives continue to appear.[6]
^Drug Enforcement Administration, Department of Justice (February 2018). "Schedules of Controlled Substances:Temporary Placement of Fentanyl-Related Substances in Schedule I. Temporary amendment; temporary scheduling order". Federal Register. 83 (25): 5188–92. PMID29932611.
^Higashikawa Y, Suzuki S (June 2008). "Studies on 1-(2-phenethyl)-4-(N -propionylanilino)piperidine (fentanyl) and its related compounds. VI. Structure-analgesic activity relationship for fentanyl, methyl-substituted fentanyls and other analogues". Forensic Toxicology. 26 (5): 1–5. doi:10.1007/s11419-007-0039-1. S2CID22092512.
^Jin WQ, Xu H, Zhu YC, Fang SN, Xia XL, Huang ZM, et al. (May 1981). "Studies on synthesis and relationship between analgesic activity and receptor affinity for 3-methyl fentanyl derivatives". Scientia Sinica. 24 (5): 710–20. PMID6264594.
^Huang ZM, Zhou J, Chen XJ, Zheng WJ, Zhang HP, Chi ZQ, et al. (September 1984). "[Analgesic activity and toxicity of potent analgesics, ohmefentanyl and mefentanyl]". Zhongguo Yao Li Xue Bao = Acta Pharmacologica Sinica. 5 (3): 153–8. PMID6239505.