Pyrithiamine is the pyridine analog of thiamine that prevents growth of organisms that require intact thiamine. [1] 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. [2] 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.[3] [4]

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[1]. Woolley, D.W., and White, A.G.C. Selective reversible inhibition of microbial growth with pyrithiamine. J. Exp. Med. 78(6), 489-497 (1943).
[2]. Woolley, D.W. An enzymatic study of the mode of action of pyrithiamine (neopyrithiamine). J. Biol. Chem. 191(1), 43-54 (1951).
[3]. Vetreno, R.P., Anzalone, S.J., and Savage, L.M. Impaired, spared, and enhanced ACh efflux across the hippocampus and striatum in diencephalic amnesia is dependent on task demands. Neurobiol. Learn Mem. 90(1), 237-244 (2008).
[4]. Zahr, N.M., Sullivan, E.V., Rohlfing, T., et al. Concomitants of alcoholism: Differential effects of thiamine deficiency, liver damage, and food deprivation on the rat brain in vivo. Psychopharmacology (Berl) 233(14), 2675-2686 (2016).