Efficacy and Safety Study of Gabapentin as add-on to Morphine in Paediatric Patients Affected by Chronic Pain

"Gabapentin: liquid oral formulation (syrup) - 75 mg/ml-three times daily. The starting dose during the optimization period will be defined according to 2 weight groups (5-15kg and \>15kg). Dose will be scaled at Day 1,3,5,14,and 21 according to a specific schedule. Maintenance dosing will be scheduled in accordance to the body weight.~Morphine: background therapy as oral, liquid and solid formulations. Patients with BW≤30kg :liquid oral formulation four times daily throughout the whole treatment period. Patients with BM\>30kg : immediate release solid and/or liquid oral formulation four times daily during titration phase and an extended release solid oral formulation twice daily during the maintenance period."

Placebo liquid oral formulation. Morphine: background therapy as oral, liquid and solid formulations. Patients with BW≤30kg :liquid oral formulation four times daily throughout the whole treatment period. Patients with BM\>30kg : immediate release solid and/or liquid oral formulation four times daily during titration phase and an extended release solid oral formulation twice daily during the maintenance period.