Medication of/-tetrahydropalmatine significantly ameliorates opiate craving and increases the abstinence rate in heroin users： a pilot study

Aim： Drug addiction is a chronic brain disease with constant relapse requiring long-term treatment. New pharmacological strategies focus on the development of an effective antirelapse drug. This study examines the effects of levotetrahydropalmatine （l-THP） on reducing heroin craving and increasing the abstinence rate among heroin-dependent patients. Methods： In total, 120 heroin-dependent patients participated in the randomized, double-blinded, and placebocontrolled study using l-THP treatment. The participants remained in a ward during a 4-week period of l-THP treatment, followed by 4 weeks of observation after treatment. The patients were followed for 3 months after discharge. Outcome measures are the measured severity of the protracted abstinence withdrawal syndrome （PAWS） and the abstinence rate. Results： Four weeks of l-THP treatment significantly ameliorated the severity of PAWS, specifically, somatic syndrome, mood states, insomnia, and drug craving, in comparison to the placebo group. Based on the 3 month follow-up observation, participants who survived the initial 2 weeks of l-THP medication and remained in the trial program had a significantly higher abstinence rate of 47.8% （95% confidence interval [CI]： 33%-67%） than the 15.2% in the placebo group （95% CI： 7%-25%）, according to a logrank test （P〈0.0005）. Conclusion：l-THP significantly ameliorated PAWS, especially reducing drug craving. Furthermore, it increased the abstinence rate among heroin users. These results support the potential use of l-THP for the treatment of heroin addiction.