Diagrammatic representation of a section across the top of the skull, showing the membranes of the brain, etc. ("Subarachnoid cavity" visible at left.)
Diagrammatic transverse section of the medulla spinalis and its membranes. (Subarachnoid cavity colored blue.)
Intrathecal administration is a route of administration for drugs via an injection into the spinal canal, or into the subarachnoid space so that it reaches the cerebrospinal fluid (CSF). It is useful in several applications, such as for spinal anesthesia, chemotherapy, or pain management. This route is also used to introduce drugs that fight certain infections, particularly post-neurosurgical. Typically, the drug is given this way to avoid being stopped by the blood–brain barrier, as it may not be able to pass into the brain when given orally. Drugs given by the intrathecal route often have to be compounded specially by a pharmacist or technician because they cannot contain any preservative or other potentially harmful inactive ingredients that are sometimes found in standard injectable drug preparations.
The route of administration is sometimes simply referred to as "intrathecal"; however, the term is also an adjective that refers to something occurring in or introduced into the anatomic spaceorpotential space inside a sheath, most commonly the arachnoid membrane of the brainorspinal cord[1] (under which is the subarachnoid space). For example, intrathecal immunoglobulin production is production of antibodies in the spinal cord.[2] The abbreviation "IT" is best not used; instead, "intrathecal" is spelled out to avoid medical mistakes.[citation needed]
Pethidine has the unusual property of being both a local anaesthetic and opioid analgesic, which occasionally permits its use as the sole intrathecal anaesthetic agent.[citation needed]
An intrathecal pump system can be used to deliver a local anaesthetic, such as ziconotide.[citation needed]
Often reserved for spastic cerebral palsy, baclofen can be administered through an intrathecal pump implanted just below the skin of the abdomen or behind the chest wall, with a catheter connected directly to the base of the spine. Intrathecal baclofen pumps sometimes carry serious clinical risks, such as infection or a possibly fatal sudden malfunction.[citation needed]
^"Route of Administration". Data Standards Manual. Food and Drug Administration. Retrieved 11 March 2011.
^Meinl, E; Krumbholz, M; Derfuss, T; Junker, A; Hohlfeld, R (2008). "Compartmentalization of inflammation in the CNS: a major mechanism driving progressive multiple sclerosis". Journal of the Neurological Sciences. 274 (1–2): 42–4. doi:10.1016/j.jns.2008.06.032. PMID18715571. S2CID34995402.
