Objective: We previously demonstrated that short-term treatment with a standardized kudzu extract (NPI-031) reduced alcohol drinking by men and women in a natural setting. The present study was conducted in nontreatment-seeking heavy drinkers to assess the safety and efficacy of 4 weeks of kudzu extract in an outpatient setting.
Method: This randomized between-subject, double-blind, placebo-controlled study involved 2 weeks of baseline, 4 weeks of treatment, and 2 weeks of follow-up. Seventeen men (21-33 years) who reported drinking 27.6 ± 6.5 drinks/week with a diagnosis of alcohol abuse/dependence took either kudzu extract (250 mg isoflavones, t.i.d.) or matched placebo on a daily basis. They reported alcohol consumption and desire to use alcohol using a wrist actigraphy device; twice weekly laboratory visits were scheduled to monitor medication adherence and adverse events.
Results: Medication adherence was excellent and there were no adverse events and changes in vital signs, blood chemistry, and renal or liver function. There was no effect on alcohol craving, but kudzu extract significantly reduced the number of drinks consumed each week by 34-57 %, reduced the number of heavy drinking days, and significantly increased the percent of days abstinent and the number of consecutive days of abstinence.
Conclusions: A standardized formulation of kudzu extract produced minimal side effects, was well-tolerated, and resulted in a modest reduction in alcohol consumption in young nontreatment-seeking heavy drinkers. Additional studies using treatment-seeking alcohol-dependent persons will be necessary to determine the usefulness of this herbal preparation in reducing alcohol use in other populations.