Veridium Six
Veridium Six was a lethal poison effective against Klingons. It had no known antidote.

In early 2367,  K'mpec was poisoned with Veridium Six. The poison slowly built up through small doses introduced into his bloodwine until the level became fatal. ()

See also
Veridium

External link

de:Veridium Sechs
Drugs
Poisonous substances