Fluvoxamine: metabolic fate in animals

Area of Science:

• Pharmacology
• Metabolomics
• Analytical Chemistry

Background:

• Fluvoxamine is a widely used antidepressant.
• Understanding drug metabolism is crucial for efficacy and safety.
• Animal models are essential for preclinical drug fate studies.

Purpose of the Study:

• To investigate the metabolic fate and identify metabolites of fluvoxamine in various animal species.
• To elucidate the primary degradation pathways of fluvoxamine in vivo.

Main Methods:

• Administration of 14C-labeled fluvoxamine to dogs, rats, hamsters, and mice.
• Collection and analysis of urine and feces for radioactivity and metabolites.
• High-performance liquid chromatography (HPLC) for metabolite profiling and isolation.
• Proton nuclear magnetic resonance (NMR) and mass spectrometry (MS) for metabolite identification.

Main Results:

• 32 radioactive substances were isolated, yielding 11 distinct metabolites across the four species.
• The primary metabolic pathway involved degradation of the aliphatic methoxyl group.
• The main metabolite was the carboxylic acid in dogs, rats, and hamsters, while the glucuronidated alcohol was significant in mice.
• Minor metabolites included the methyl ester and products of amino group modification.
• Both (E)- and (Z)-isomers of some metabolites were observed.
• The parent fluvoxamine compound was found in low amounts (<10%) in dog urine.

Conclusions:

• Fluvoxamine is extensively metabolized in dogs, rats, hamsters, and mice.
• The methoxyl group is the main site of degradation, leading to species-specific major metabolites.
• Metabolite profiles indicate potential for stereoisomer formation during degradation.
• These findings provide comprehensive insights into the pharmacokinetic profile of fluvoxamine in preclinical species.