Intrathecal betamethasone for cancer pain: A study of its analgesic efficacy and safety

BACKGROUND: A preliminary study has shown effective cancer pain relief by intrathecal betamethasone (ITB). However, further evidence is needed to support this new approach. METHODS: Cancer patients with opioid‐resistant pain received lumbar intrathecal administration of betamethasone 2 or 3 mg once a week for 28 days. Immediate and short‐term analgesia (using a percentage pain reduction scale and a numerical rating scale, NRS) and long‐term analgesia (using NRS) were assessed. Patients were classified into two groups according to the most painful site of metastasis: vertebral column and/or surrounding nerve plexus metastases (group A) and other metastases distal from the vertebral column (group B). RESULTS: A total of 104 patients received ITB. Pain relief was observed not only in the lower half but also in the upper half of the body. The proportion of group A patients who experienced immediate analgesia was 81% (47/58), which was significantly greater than that of group B (P < 0.001). A decrease in NRS scores 1 day after ITB administration was observed in significantly more patients in group A than in group B (P < 0.001). Long‐term analgesia was also recorded in a greater proportion of patients in group A than in group B in the 7‐day (59%, 38/64 vs 6%, 2/33) and 28‐day periods (71%, 40/56 vs 31%, 8/26) (P < 0.001). No adverse effects related to neurotoxicity were recorded. CONCLUSION: Intrathecal injection of betamethasone produced analgesia for opioid‐resistant cancer pain, and may be a potent therapeutic option for intolerable pain from vertebral column and/or surrounding nerve plexus metastases.