Metabolic N-oxidation products of aliphatic amines as potential mediators in amine pharmacology

Whilst it has long been recognized that many tertiary amines are converted by the body into the corresponding amine oxides, little attention has, until recently, been paid to the metabolic oxidation of the nitrogen occurring in primary and secondary basic amines. Moreover, the extreme water solubility of tertiary amine oxides generally rendered them pharmacologically inert. In contrast, the primary and secondary hydroxylamines derived from aralkylamines are lipophilic substances and could well be involved in the pharmacological activity of this group of drugs. Data are presented on the metabolic formation of these N-oxidation products from a variety of basic drugs, and evidence for the involvement of these metabolites in the pharmacology of these drugs is discussed.