Criteria for discontinuing or modifying allocated interventions {11b}
pain
The patients are allowed to withdraw their consent at any time during the trial. They will then return their medication to the coordinating center. We anticipate that this may be due to either insufficient pain relief despite the maximal allowed dose or the occurrence of side effects. We will not allow modification of the allocated intervention or increase of the dose above the maximal indicated dosages. In such cases, the patient will be taken out of the study and the medication is returned to the coordinating center. Irrespective of duration of treatment, the data from patients that dropped out after initiation of treatment will be included in the intention-to-treat analysis. Additionally, we will describe into detail the characteristics of the patients that dropped out and reason for dropping out.