After randomisation, baseline (time 0) pain score will be recorded. If the baseline pain score falls outside the range of 60 to 80 mm on the VAS or 6-8 on WBF, the patient will be withdrawn from the study (randomised but not treated). Patients who have a pain score between 60 and 80 mm on the VAS or 6-8 on WBF at screening, validation and baseline (time 0) will be eligible to receive treatment.