Efficacy of a new once daily hydromorphone formulation in comparison with twice daily administration in chronic pain: a randomized, double-blind, cross-over study.

Objective Efficacy and safety of a novel multiple-unit hydromorphone once daily (HOD) was compared to an established hydromorphone twice daily (HTD) regimen in patients with moderate-to-severe chronic pain. Design and methods The results from a randomized, double-blind, multicenter, cross-over trial in patients (n = 37) with chronic malignant or non-malignant pain are reported. The primary efficacy parameter was current pain on 0-100 mm VAS assessed four times daily and prior to intake of rescue medication (immediate-release hydromorphone) throughout the last 5 days with each treatment (after an 8 day build-up period to avoid carry-over effects).