Purity >95%. Pyrithiamine is the pyridine analog of thiamine that prevents growth of organisms that require intact thiamine. It inhibits the growth of bacterial and fungal species at a pyrithiamine:thiamine ratio of 10:1 in growth media and induces symptoms of thiamine deficiency in mice at a dietary ratio of 3:1. These effects are reversible with addition of sufficient thiamine in all species. Pyrithiamine inhibits the formation of cocarboxylase from thiamine in chicken blood in a dose-dependent manner. It has been used to induce thiamine deficiency in various disease models, including rat models of alcoholism and diencephalic amnesia, to study the effects of thiamine deficiency on disease pathology.