A method of screening a compound or a composition for use in modulating opioid withdrawal symptoms in a mammal. The method comprises the steps of: selecting a group of test animals； separating the group into two subgroups； inducing Panx1 activation or expression in both subgroups； dosing a first subgroup with a candidate compound； dosing a second subgroup with a placebo； measuring ATP released in spinal microglia of test animals in the first subgroup and in the spinal microglia of test animals in the second subgroup； quantifying the difference in ATP released in spinal microglia of test animals in the first subgroup and in the spinal microglia of test animals in the second subgroup； if the difference in the ATP released in the first subgroup and the APT released in the second subgroup is greater than 25%, then formulating the candidate compound into a pharmaceutical composition.
