The Great Paracelsus (Philipus Aureolus Theophrastus Bonihastus von Hohenheini-Paracelsus, 1493-1541) is remembered by toxicologists for his famous quote: "All substances are poisons; there is none which is not a poison. The right dose differentiates a poison from a remedy-"' Indeed, the basic principle from the quotation still applies today. The right dose of morphine that will produce a blood level of approximately 0.07 mg,/L to 0.083 mg/L is essential for the relief of pain. An overdose that results in a markedly increased blood level (0.2 mg/L to 2.3 mg/L) can cause death due to central nervous system depression. In general, the same applies to all chemical substances.
Pharmacogenomics and its applications
White, R., & Wong, SHY. (2005). Pharmacogenomics and its applications. MLO: Medical Laboratory Observer, 37(3), 20-27.