The present invention is directed to an implantable drug depot useful for reducing, preventing or treating post-operative pain in a patient in need of such treatment, the implantable drug depot comprising a therapeutically effective amount of clonidine or pharmaceutically acceptable salt thereof and a polymer; wherein the depot is implantable at a site beneath the skin to reduce, prevent or treat post-operative pain, and the depot is capable of releasing (i) about 5% to about 45% of the clonidine or pharmaceutically acceptable salt thereof relative to a total amount of the clonidine or pharmaceutically acceptable salt thereof loaded in the drug depot over a first period of up to 48 hours and (ii) about 55% to about 95% of the clonidine or pharmaceutically acceptable salt thereof relative to a total amount of the clonidine or pharmaceutically acceptable salt thereof loaded in the drug depot over a subsequent period of at least 3 days.