Cysteamine metabolites

The chemical and toxicologic characterization of the electrophilic nature of the reactive acetaminophen metabolite has led to the development of effective antidotes—cysteamine and /V-acetylcysteine. Administration of /V-acetylcysteine (the safer... 

Cysteamine apparently is an effective antidote not only in mice ( ) but also in man ( ). At first it was assumed that this compound exerted its effect by serving as an alternative nucelophile in the inactivation of the chemically reactive metabolite. It is also possible, however, that cysteamine may act by inhibiting the formation of the chemically reactive metabolite (41) and by serving as a precursor of sulfate, required for the formation of PAPS. Unfortunately, it is difficult to differentiate among these mechanisms. 

However, as far as the biosynthesis is considered, the cysteinesulfinic (CSA) pathway and the cysteamine pathway are considered as prevalent each tissue showing a preference for the one of the other route In this respect, it is of interest that in these both pathways the intermediate metabolite formed is hypotaurine 5 The metabolism of hypotaurine is not clearly known, although the oxidation of hypotaurine into taurine is... 

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