Effectiveness of Ketamine in Malignant Neuropathic Pain Relief

Overview

To see whether the addition of low-dose ketamine to a subcutaneous morphine infusion improves analgesia in patients with neuropathic cancer pain.

Patients with cancer pain judged to have a neuropathic component and receiving pain treatment with a subcutaneous infusion of morphine will be included in a randomized, double blind, placebo-controlled, crossover study. All patients will be recruited from hospital wards (Haukeland University Hospital, Bergen). In the case of patient withdrawal or dropout, new patients will be recruited so that the total number of patients completing the study will be 20. Data from patients not completing the study will solely be used to provide information about adverse effects. The basic treatment with subcutaneous morphine infusion will be supplemented with a separate subcutaneous infusion of ketamine 1 mg/kg/ 24 hours or NaCl 9 mg/ml (placebo). After 48 hours (phase 1) there will be a "wash-out" period of minimum 10 hours to minimize carryover effects before the treatment is replaced by the alternative treatment for a further 48 hours (phase 2) in a standard crossover design. The treatment duration is based on ketamine's short plasma half-life which is less than 2 hours after initial equilibration. Pain intensity (using NRS) will be recorded at rest and on movement x 4 daily. Rescue medication in the form of morphine subcutaneous bolus may be given to the patient as required. There will be a" lockout" time of 1 hour which means that the rescue dose of morphine can be repeated every 60 minutes if necessary, providing the patient is awake and has a respiratory rate of 8 or more per minute.Randomization will be performed by Haukeland University Hospital Pharmacy. The study drug/ placebo will also be prepared by the hospital pharmacy according to a standard instruction.

Conditions

Interventions

Eligibility

Locations (1)

Outcomes