A systematic review of subcutaneous versus intramuscular or intravenous routes of opioid administration on pain outcomes in cancer and post-surgical clinical populations - challenging current assumptions in palliative care practice.

Objective: The objective of this review is to investigate the use of the subcutaneous route of administration of analgesics, common practice within palliative medicine.

Design: Systematic review using consensus approach, direct comparison of subcutaneous route with intravenous and intramuscular routes.

Results: The limited available evidence demonstrates non-inferiority of the subcutaneous route in both cancer patients and those post-surgery.