Fenmetozole Tosylate is an antagonist of the actions of ethanol, also antagonizes α2-adrenergic receptor, and acts as an antidepressant drug.

Fenmetozole acts as an antagonist of α2-adrenergic receptor[3].

In mice, fenmetozole antagonizes both the ethanol induced increase in locomotor activity at 2.0 g/kg and the decrease caused by 4.0 g/kg. Moreover, fenmetozole attenuates the ethanol-induced reduction in cerebellar cyclic guanosine monophosphate content, but it significantly elevates cGMP levels in this tissue. Fenmetozole does not change ethanol induced increases in punished drinking in a conflict test, but when given at a high dose, fenmetozole decreases both punished and unpunished responding. Fenmetozole fails to precipitate ethanol withdrawal-like reactions when it is given to physically-dependent, intoxicated rats. Fenmetozole (15-30 g/kg) reduces ethanol-induced impairment of the aerial righting reflex without altering blood or brain ethanol content[1]. Fenmetozole alone has no ffect on punished drinking and does not alter ethanol action in the paradigm except at the highest dose tested (30 mg/kg) in rats[2].

[1]. Frye GD, et al. An evaluation of the selectivity of fenmetozole (DH-524) reversal of ethanol-induced changes in central nervous system function. Psychopharmacology (Berl). 1980;69(2):149-55. [2]. Vogel RA, et al. Differential effects of TRH, amphetamine, naloxone, and fenmetozole on ethanol actions: attenuation of the effects of punishment and impairment of aerial righting reflex. Alcohol Clin Exp Res. 1981 Summer;5(3):386-92. [3]. Stillings MR, et al. Effect of methoxy substitution on the adrenergic activity of three structurally related alpha 2-adrenoreceptor antagonists. J Med Chem. 1986 Sep;29(9):1780-3.