Microsomal catalyzed N-hydroxylation of guanfacine and reduction of N-hydroxyguanfacine.

Article Details

Citation

Clement B, Demesmaeker M

Microsomal catalyzed N-hydroxylation of guanfacine and reduction of N-hydroxyguanfacine.

Arch Pharm (Weinheim). 1997 Oct;330(9-10):303-6.

PubMed ID
9396389 [ View in PubMed
]
Abstract

Guanfacine 1 is a well known centrally acting alpha 2-adrenoceptor agonist with antihypertensive activity. The drug belongs to the guanidine class of compounds. The N-oxidative biotransformation of guanfacine was investigated in vitro in the presence of hepatic microsomal fractions from rabbits, pigs, and humans. The N-hydroxylated derivative N-hydroxyguanfacine 2 had to be synthesized as reference for the identification of the metabolite. The corresponding in vitro retroreduction of N-hydroxyguanfacine 2 was also investigated using the same set of enzyme sources. A new HPLC analytical method was developed in order to isolate and quantify the metabolites. A complete metabolic cycle involving the oxidative metabolism of guanfacine could only be observed in the presence of microsomal fractions from rabbitt livers, whereas enzyme sources of all species under investigation catalyzed the N-reduction of N-hydroxyguanfacine 2.

DrugBank Data that Cites this Article

Drug Enzymes
DrugEnzymeKindOrganismPharmacological ActionActions
GuanfacineCytochrome P450 2C19ProteinHumans
Unknown
Substrate
Details
GuanfacineCytochrome P450 3A4ProteinHumans
Unknown
Substrate
Details