Route of Delivery

Oral

Preferred route of opioid delivery; as effective as parenteral opioid at equianalgesic doses.

If oral route not possible (e.g. head and neck tumor, bowel obstruction, nausea/vomiting) one or more of the following routes may be appropriate

Most opioids can be delivered by this route as a continuous infusion or by bolus dosing; methadone can be a skin irritant and must be diluted.

There is little logic for using this route as opioids are well absorbed subcutaneously.

Not commonly used in palliative care; dose is equivalent to subcutaneous dose.

Several opioids are available in patch formulations that are well absorbed through the skin (e.g. fentanyl {Durogesic®}, buprenorphine {Norspan®}).

Transmucosal (fentanyl lozenge {Actiq®}, buccal tablets), rectal suppositories, intranasal spray, sublingual drops.