EUCTR2014‐004718‐27‐PL.

Methods	Title: a study comparing the effectiveness and safety of tramadol and micronized magnesium lactate as functional excipient to tramadol alone for the treatment of moderate to severe pain due to osteoarthritis (OA). Randomized, multicenter, single‐blinded, parallel‐group study that seeks to assess the efficacy, safety and tolerability of the combination of IR tramadol with micronized magnesium lactate in managing chronic pain in people with OA of the hip or knee, or both
Participants	Adults with clinical diagnosis of OA of hip or knee (or both), based on ACR and radiographic criteria (presence of knee or hip joint symptoms (pain, stiffness, disability) and signs (bony crepitus), and radiographic evidence of OA (functional class I–III)). Inclusion criteria Men (not less than 35% of all participants) and women aged 18–75 years (with negative pregnancy test at baseline) of non‐childbearing potential or if of childbearing potential, using a medically acceptable form of contraception Baseline numeric rating scale PI score NRS‐11 = 4 (at day 1) before randomization to study treatments. Suboptimal response to non‐opioid treatment as judged by investigator Willing to withhold any medicines that may interfere with tramadol metabolism for 2 weeks prior to start of the study and continue to withhold them during treatment periods.
Interventions	Non‐inferiority study. Main objective is to evaluate efficacy, safety and tolerability of the new formulation composed of tramadol 50 mg and micronized magnesium lactate 75 mg of magnesium ions in the application of daily dose tramadol 150 mg/magnesium lactate 225 mg for the management of chronic pain. Secondary objective is to assess acceptance during disease treatment and to collect data on quality of life and the impact on the economy (cost‐effectiveness analysis and cost utility analysis).
Outcomes	Major outcome PI: change between baseline (V1) to end of treatment (V4 or the day of discontinuation) of PI measured on 11‐point PI‐NRS that is achieved on the day of therapy discontinuation or at the end of the trial. Minor outcome Quality of life and impact on the economy on the day of therapy discontinuation or at the end of the trial.
Notes	World Health Organization International Clinical Trials Registry Platform Main ID: EUCTR2014‐004718‐27‐PL URL: www.clinicaltrialsregister.eu/ctr‐search/search?query=eudract_number:2014‐004718‐27 Contact Information: Department of Pharmacodynamics Address: 1B Banacha Street, 02‐097, Warsaw, Poland Telephone: +4822116 61 26 Email: farmakodynamika@wum.edu.pl Affiliation: Medical University of Warsaw