Pseudomorphine (also known as oxydimorphine or dehydromorphine) is an inactive, natural dimerisation product of the morphine molecule in tandem and thus a common impurity in morphine concentrations. It was first described by Pelletier in 1835.[1]
This compound may be synthesized by the oxidative coupling of morphine by potassium ferricyanide.[2]
Pseudomorphine contributes very little to morphine's effects. It produces no effects in the central nervous or gastrointestinal systems, but it might have some effects on the circulatory system.[3]