Comparison of Morphine and Tramadol in Transforaminal Epidural Injections for Lumbar Radicular Pain

BACKGROUND Transforaminal epidural steroid injections are known to reduce inflammation by inhibiting synthesis of various proinflammatory mediators and have been used increasingly. The anti-inflammatory properties of opioids are not as fully understood but apparently involve antagonism sensory neuron excitability and pro-inflammatory neuropeptide release. To date, no studies have addressed the efficacy of transforaminal epidural morphine in patients with radicular pain, and none have directly compared morphine with a tramadol for this indication. The aim of this study was to compare morphine and tramadol analgesia when administered via epidural injection to patients with lumbar radicular pain. METHODS A total of 59 patients were randomly allocated to 1 of 2 treatment groups and followed for 3 months after procedure. Each patient was subjected to C-arm guided transforaminal epidural injection (TFEI) of an affected nerve root. As assigned, patients received either morphine sulfate (2.5 mg/2.5 ml) or tramadol (25 mg/0.5 ml) in combination with 0.2% ropivacaine (1 ml). Using numeric rating scale was subsequently rates at 2 weeks and 3 months following injection for comparison with baseline. RESULTS Both groups had significantly lower mean pain scores at 2 weeks and at 3 months after treatment, but outcomes did not differ significantly between groups. CONCLUSIONS TFEI of an opioid plus local anesthetic proved effective in treating radicular pain. Although morphine surpassed tramadol in pain relief scores, the difference was not statistically significant.