Patients will be randomly assigned to the Celestone group (N = 60) or the control group (N = 60). The allocation of patients into either group will be performed using a computer-generated randomization program. Each patient's randomization number will be concealed until the end of the study from both the patients and the outcome assessor, who will be an independent research coordinator at the investigators pain clinic. The patients will be explained that they will not know which medicine they will receive until the study completion.