Neuraxial direct drug delivery occurs by accessing the epidural or subarachnoid space by a needle or an infusion system for severe and refractory pain.
Direct delivery of drugs to the CSF where the drug circulates, and adsorbs onto CNS effector sites without systemic toxicity and allows rapid pain control (Brogan SE).
Should be considered when pain cannot be contained by systemic drugs or because of dose limiting toxicity.
Intrathecal drug delivery has replaced the epidural route as the latter is associated with more frequent treatment failure because of catheter displacement, epidural fibrosis which impedes CSF flow.
Technical difficulties with long-term epidural infusions occurs 55% of the time, and with intrathecal infusions 5%.