PCM

PCM (or PentoCyleinicMethylhydrane) was used by the Usurians to pacify their slave populations. It minimized the need for huge numbers of guards and eliminated airborne infection, but had the side-effects of inducing anxiety and debilitating the wills of those affected. It was less effective in the Undercity of Megropolis One and in the mines of Megropolis Three.

There was an antidote to this anxiety-inducing agent, which only higher executive grades were allowed to take (marked "for official use only"). (DW: The Sun Makers)