Which route of administration is preferred if immediate analgesia and rapid titration are necessary?

Intravenous (IV)

The IV route is preferred as the fastest and most amenable to titration. A PCA bolus can be delivered; however, the pump will limit the dosage that can be delivered unless the parameters are changed. Intraspinal administration requires special catheter placement and there are more potential complications with this route. Sublingual is reasonably fast, but not a good route for titration, medication variety in this form is limited.