Efficacy and Safety of Intrathecal Opioid/Bupivacaine Mixture in Chronic Nonmalignant Pain: A Double Blind, Randomized, Crossover, Multicenter Study by the National Forum of Independent Pain Clinicians (NFIPC).

Objective. Intrathecal opioid/local anesthetic mixtures are a popular alternative in contemporary treatment of chronic nonmalignant pain. Unfortunately, its use is based solely on retrospective studies or anecdotal reports. Materials and Methods. A double blind, randomized, crossover, multicenter study was performed in 24 patients with intrathecal pumps. For four consecutive months, their pumps were refilled with either the original opioid or its mixture with different concentrations of bupivacaine(4, 6, or 8 mg/day). Results. Only one patient experienced mild side effects from intrathecal bupivacaine. A strong placebo response was observed in all patients when they entered the study. Addition of bupivacaine to the intrathecal opioid failed to produce significant improvement in pain control. Conclusion. At currently used doses, intrathecal opioid bupivacaine mixtures are not more efficacious in the treatment of chronic nonmalignant pain than opioid alone.