A high proportion of persons convicted of driving while impaired repeat the offense. Many continue drinking and driving, even when faced with long jail terms. Hence, they pose a serious public health threat. This preliminary study evaluated extended-release, injectable naltrexone suspension (XR-NTX) and supportive therapy in reducing (1) drinking and (2) attempts to drive after drinking among repeat driving while impaired offenders with an ignition interlock device installed in their vehicles.
Treatment-seeking volunteers received medical management therapy and 3 monthly injections of XR-NTX. We compared data on alcohol consumption, alcohol biomarkers, and interlock information before, during, and after treatment using summary measures and Sign tests.
Of 12 consented subjects, 10 received at least 1 injection, and 7 received all 3 injections. All subjects receiving medication reported a decrease in average drinks per day (P < 0.01) and abstinent days (P = 0.02) while on treatment versus pretreatment levels. Average daily drinks decreased by 77%, from 3.0 to 0.69 (P < 0.01), during treatment with XR-NTX. Average drinks per drinking day also declined by 39% during treatment, from 6.6 to 4.0 (P = 0.04). Percent days abstinent increased by 31%, from 56.8 to 81.96 (P = 0.02), which persisted after treatment completion. Biomarkers were consistent with reduced drinking. The percentage of vehicular failures to start due to elevated breath alcohol decreased from 3.1% of tests to 1.29% of tests.
A randomized, controlled clinical trial is needed to demonstrate the efficacy of this promising treatment regimen for repeat offenders.