Pro
The Royal Dutch Society for the Advancement of Pharmacy wrote in its 1994 report titled "Administration and Compounding of Euthanasic Agents":
“A clear general conclusion may be drawn as concerns the lethal action of the euthanasic agents recommended by the KNMP’s [Royal Dutch Society for the Advancement of Pharmacy] Task Force: the administration of thiopental [a drug that causes unconsciousness] followed by a muscle relaxant–provided the latter is properly administered–causes immediate death without any problems…
Intravenous administration is the most reliable and rapid way to accomplish euthanasia and therefore can be safely recommended.”
1994