OBJECTIVES: Low back pain is a serious problem that results in lost time from work and reduced quality of life. The annual cost of low back pain in the United States is estimated to be billions of dollars. The primary objective of this study was to characterize the most commonly used drug therapies for treatment of low back pain in a managed care organization (MCO). METHODS: We performed a retrospective analysis on enrollment, medical, and pharmacy claims data from 19 discounted, fee-for-service, independent practice association model plans affiliated with a large MCO. Commercial members with a claim for low back pain identified by appropriate ICD-9 codes during a specified 6-month period were included for analysis. Results were stratified based on the following treatment patterns: new treatment, ongoing treatment, and no treatment. RESULTS: About half of the 96,024 diagnosed patients did not fill a prescription, and the new and ongoing treatment groups were about evenly split. Mean age was 42 years, with 46.7% male. About half of subjects received >1 drug. In both the new and ongoing groups hydrocodone/acetaminophen was the most common pain medication for both groups, prescribed in 27.7% and 41.2% of cases, respectively. Naproxen was the second most prescribed drug for newly treated patients (25.8%) and cyclopbenzaprine (21%) the second most prescribed drug in the ongoing group. Oxycodone/acetaminophen was used in 7.6% of the newly treated patients and in 13% of the ongoing group. Oxycodone was used in 8.1% of the ongoing group, but was not among the top 20 drugs prescribed in the newly treated group. CONCLUSIONS: We observed titration in treatment for pain in the ongoing users who switched to more potent, long-acting medications to control their low back pain. The increased utilization of narcotic analgesics could have significant quality of care, productivity, disability, and cost implications.