Inhibits AChE selectively over BChE, with a bimolecular rate constant similar to pyridostigmine. [11C]MDDP; N-[11C]Methyl-3-[[(dimethylamino)carbonyl]oxy]-2-(2',2'-diphenylpropionoxymethyl)pyridinium. Used as PET imaging of a novel potential heart acetylcholinesterase tracer by Wang et al.