In my fantasy story, there is a kind of sedative referred to as "Violet Toxin" in the common tongue. It's kinda a hand wave multi-purpose liquid. In small, heavily diluted doses, it works like a traditional sedative and can also act as a painkiller. In stronger doses, small concentrations of the liquid, it functions as a tranquilizer. And in high concentrations and overdoses it can induce sustained loss of memory prior to the point where the sedative was introduced to the body, provided it doesn't kill you from overdosing, for as long as there is some concentration of it. Does such a chemical or mixture thereof exist in real life that I can use for reference?