Kudzu Extract Treatment Does Not Increase the Intoxicating Effects of Acute Alcohol in Human Volunteers

Abstract

Background Isoflavone administration in the form of a purified extract from the herbal medication kudzu root has been shown to reduce, but not eliminate, alcohol consumption in alcohol-abusing and alcohol-dependent men. The precise mechanism of this action is unknown, but one possible explanation for these results is that the isoflavones in kudzu might actually increase the intensity or duration of alcohol’s effects and thus delay the desire for subsequent drinks. The present study was designed to test this hypothesis. Methods Twelve (12) healthy adult men and women (27.5±1.89 yrs old) who consumed moderate amounts of alcohol (7.8±0.63 drinks/week) participated in a double-blind, placebo-controlled crossover study in which they were treated with either kudzu extract (total isoflavone dose of 750 mg/day) or matched placebo for nine days. On days 8 and 9, participants received an acute challenge of ethyl alcohol (either 0.35 or 0.7 g/kg alcohol). During the challenges the following measures were collected: subjective effects, psychomotor (body sway), cognitive performance (vigilance/reaction time), physiological measures (heart rate and skin temperature), and plasma ethanol concentration. Results Alcohol resulted in a dose-related alteration in subjective measures of intoxication, impairment of stance stability, and vigilance/reaction time. Kudzu extract did not alter participants’ subjective responses to the alcohol challenge or to alcohol’s effects on stance stability or vigilance/reaction time. However, individuals treated with kudzu extract experienced a slightly more rapid rise in plasma ethanol levels, but only after the 0.7 g/kg dose. This transient effect during the first 30 minutes of the ascending plasma alcohol curve lasted only 10-15 minutes; there were no differences in peak plasma alcohol levels or alcohol elimination kinetics. Additionally, kudzu pretreatment enhanced the effects of the 0.7 g/kg dose of alcohol on heart rate and skin temperature. Conclusions These data suggest that individuals who drink alcohol while being treated with kudzu extract experience no adverse consequences and further, the reported reductions in alcohol intake after kudzu extract treatment are not related to an alteration in alcohol’s subjective or psychomotor effects.

The isoflavone puerarin reduces alcohol intake in heavy drinkers: A pilot study

“…Also consistent with our previous work, subjective reports of craving or desire to drink were not altered by puerarin administration. This strengthens the hypothesis that isoflavones are not reducing drinking by altering the subjective/perceived effects of alcohol (Penetar etal., 2011). …”

A single dose of kudzu extract reduces alcohol consumption in a binge drinking paradigm

“…The correlational analysis of absolute amount of alcohol consumed and breath alcohol levels in this study indicates that the physiological effects and the rate of elimination of ingested alcohol are not altered by kudzu administration. This was demonstrated in our previous study (Penetar et al, 2011) where pharmacokinetic parameters such as peak concentration and elimination time were not affected by kudzu. In that study, however, we did find evidence of an initial more rapid rise in blood alcohol levels in kudzu-treated individuals, suggesting that isoflavones may alter bioavailability of alcohol to the brain during the ascending alcohol absorption phase.…”

“…The apparently lower magnitude of subjective effects compared to the placebo treated group (Figure 4) is due most likely to the fact that the kudzu-treated individuals drank less alcohol during the session, which was reflected in significantly lower breath alcohol levels. When given equal amounts of alcohol, kudzu- and placebo-treated individuals respond similarly (Penetar et al, 2011). …”

Pharmacotherapy for Alcohol Use Disorder

“…124 Following alcohol consumption, kudzu extract appears to contribute to a faster increase in blood alcohol level, likely resulting in more rapid entry of alcohol to the central nervous system, effectively increasing alcohol-related reward from the first drink during an episode. 125 Consequently, elevated alcohol-related reward following the first drink may increase the time to a subsequent drink. Seven-day treatment with a kudzu extract preparation has been shown to significantly decrease consumption of alcohol in the laboratory among heavy drinkers.…”