sentences:  β-hydroxythiofentanyl was anecdotally said to be one of the more favored fentanyl analogues by opiate addicts, but nevertheless its brief career as a street drug did not survive the introduction of the Analogues Act.Betahydroxythiofentanyl has similar effects to fentanyl.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.