Contingency management is effective in promoting abstinence and retention in treatment among crack cocaine users with a previous history of poor treatment response: a crossover trial

A Systematic Review of the Efficacy of Contingency Management for Substance Use Disorders in Low and Middle Income Countries

BACKGROUND

The impact of illicit substance use is especially devastating in low-resourced countries where factors such as poverty, unemployment, and inadequate services impede successful treatment. Contingency management (CM) is a treatment for substance use disorders that has shown to be effective in eliciting behaviour change. The efficacy of CM interventions in low and middle income countries (LMICs) has been under explored.

METHODS

The aim of this systematic review of randomized controlled trials was to assess measures of CM efficacy in addressing substance use disorders, while also considering contextual moderators of CM in LMICs. A search of PubMed, Scopus, and Cochrane library databases yielded 18 studies for inclusion, from which relevant data were extracted using modified versions of the Cochrane Characteristics of Studies tool.

RESULTS

Two studies were located in a low-income country, two in lower-middle income countries, and fourteen in upper middle-income countries. Overall, estimated efficacy estimates were similar to those from higher income countries. However, context-specific challenges that warrant further investigation included limited access to trained staff and structural and financial constraints.

CONCLUSIONS

While CM in LMICs is in its early stages of development, efficacy estimates were not substantially different compared to high income countries. Challenges such as costs, willingness to implement, and the stigma associated with addiction sets the stage for further research in these contexts.

Histopathological and inflammatory response in multiple organs of rats exposed to crack

The aim of this study was to investigate histopathological and inflammatory response in liver and kidney of rats after crack exposure. For this purpose, a total of 32 male Wistar rats were distributed into four groups: (G1) and (G2): received 18 mg/kg of body weight (b.w) of crack cocaine, but Group G2 remained 72 h without exposure after the experimental period (5 days). Experimental group 3 (G3): received 36 mg/kg of body weight (b.w) of crack cocaine. Control Group (CTRL): received only the vehicle (DMSO) administered by intraperitoneal (i.p) route for 5 days. The results showed that crack cocaine induced histopathological changes in liver and kidney. Immunohistochemistry data revealed that G2 group showed a higher immunoexpression of Ki-67 in hepatic and renal tissues. Regarding inflammation, the results showed that all groups exposed to crack cocaine decreased the expression of TNF-α, IL-6, and IL-10 in liver and kidney. In summary, our results showed that the subacute doses of crack cocaine used in this study had cytotoxic, and immunosuppressive effects in liver and kidney of rats, especially at 36 mg/kg dose. Since cellular death and inflammation participates in the multi-step process of chemical carcinogenesis, these data offer new insights into potential ways to understand the pathobiological mechanisms induced by crack cocaine in several tissues and organs.