A combination of isradipine and naltrexone blocks cocaine's enhancement of a cocaine place preference.

Rats were conditioned by pairing cocaine with one side of an alley and placebo with the other. After conditioning, compared to Baseline and a placebo-control group, rats spent more time in the place of cocaine experience. Subsequently, there were further tests except now cocaine was given just before the test session in addition to one of two other kinds of injections. One of these additional injections was a placebo and the other was a combination of a small dose of isradipine (1 mg/kg) and a dose of naltrexone (3 mg/kg) (ISR + NTX). Measures of gross activity (movement from one side of the alley to the other) were taken during testing. ISR + NTX blocked cocaine's ability to sustain a place preference. ISR + NTX also blocked sensitization of cocaine's ability to enhance locomotor activity. This blockade of cocaine's usual effects indicates that ISR + NTX may have a role in treating cocaine use disorders.