Subcutaneous Versus Intravenous Morphine When Switching From Oral to Parenteral Route in Palliative Cancer Patients

Overview

The investigators aim to establish whether the intravenous or the subcutaneous route of administration has clinically significant advantages when parenteral administration of morphine is started with a combination of continuous infusion and bolus doses in palliative cancer patients. Patients admitted to a Hospital palliative medicine unit with an indication for parenteral administration of morphine will be recruited. The patients will have two similar infusion pumps with continuous infusion and bolus function. One infusion pump will be connected to an intravenous line, the other to a subcutaneous line. One pump contains morphine, one placebo. The primary endpoint is the time from initiation of infusion with titration to the final infusion rate that provides pain control is reached.

Intravenous administration has theoretical advantages in more predictable pharmacokinetics and shorter time to maximum effect. Subcutaneous administration is less invasive, requires less specialized personnel and equipment, and probably poses a lower risk of complications than an intravenous line. Traditionally the subcutaneous route has been the recommended first choice for parenteral administration of opioids for palliative cancer patients. The investigators aim to establish whether the intravenous or the subcutaneous route of administration has clinically significant advantages when parenteral administration of morphine is started with a combination of continuous infusion and bolus doses in palliative cancer patients. Patients admitted to a Hospital palliative medicine unit with an indication for parenteral administration of morphine will be recruited. The patients will have two similar infusion pumps with continuous infusion and bolus function. One infusion pump will be connected to an intravenous line, the other to a subcutaneous line. One pump contains morphine, one placebo. The primary endpoint is the time from initiation of infusion with titration to the final infusion rate that provides pain control is reached. Secondary endpoints are time from bolus administration to pain relief, comparison of Tmax, Cmax, and size of AUC0-60 after bolus doses, the number of bolus doses first 24 and 48 hours, and the number of patients reaching acceptable pain relief within 48 hours.