Incorporation into Endogenous Metabolic Pathways of Small Fragments Derived from I.C.I. 58,834 (Viloxazine)

Abstract

1. Metabolic degradation of the tetrahydro-oxazine ring of 2-(2-ethoxy-phenoxymethyl)-2,3,5,6-tetrahydro-1,4-oxazine (I.C.I. 58,834)* gives rise to one- or two-carbon fragments which are utilized by endogenous metabolic pathways.

2. Evidence of this in dogs is shown by the ¹⁴C-labelled residues in tissues, ¹⁴C-labelled material in blood which has a half-life of three weeks, and elimination of [¹⁴C]urea in urine.

3. The same phenomenon occurs in rat, mouse and man, but to a smaller extent than in the dog.

4. Intravenous administration of [¹⁴C]ethanolamine to a dog gave rise to residual ¹⁴C blood levels with a half-life comparable to that produced by metabolic incorporation of ¹⁴C from ¹⁴C-I.C.I. 58,834.