Effective treatments of pain for extended periods of time are provided. The treatments include the administration of one or more drug depots intraspinally wherein the drug depots include an effective amount of baclofen formulated within a polyorthoester. By administration of one or more drug depots, one can relieve pain caused by diverse sources, including but not limited to chronic pelvic pain syndromes, spinal disc herniation (i.e. sciatica), spondilothesis, stenosis, discongenic back pain and joint pain, as well as pain that is incidental to surgery. In some embodiments, the relief can be for at least thirty days, at least sixty days, at least one hundred days or at least one hundred and thirty-five days.