Non-Prescribed Buprenorphine Use Mediates the Relationship between Heroin Use and Kratom Use among a Sample of Polysubstance Users.

In Asia, (e.g., "kratom") has been used to mitigate alcohol and drug dependence. Some preliminary findings suggest kratom's potential use as an informal harm-reduction method in the United States, such as an opioid substitute or as a means of lessening opioid withdrawal symptoms. To determine correlates of past-year kratom use among a sample of polysubstance users enrolled in residential recovery programs in Kentucky, an anonymous survey was completed by clients in April 2017. Logistic regression was used to identify significant associations with past-year kratom use. Of the final sample ( = 478), 10.4% reported past-year kratom use. Past-year heroin use, but not past-year prescription opioid (e.g., oxycodone, hydrocodone) use, was significantly associated with kratom use, such that individuals who reported past-year heroin use were 2.5 times more likely to also report past-year kratom use. Non-prescribed buprenorphine (i.e., Suboxone) use partially mediated the relationship between past-year heroin and kratom use by explaining 36% of the association between the two drugs. Though amphetamines were highly preferred, past-year use was negatively correlated with past-year kratom use. Rates of past-year kratom use were lower than rates of alcohol and illicit drug use. Kratom was not preferred over heroin or prescription opioids.