methonium
noun
me·tho·ni·um
| \ mə-ˈthō-nē-əm
\
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Medical Definition of methonium
: any of several bivalent doubled substituted ammonium ions (as decamethonium or hexamethonium) in which the two quaternary nitrogen atoms are separated by a polymethylene chain
methonium salts used in the treatment of hypertension