What does intrathecal administration involve?

Intrathecal administration refers to the delivery of medication directly into the cerebrospinal fluid (CSF) that surrounds the spinal cord. This method is often utilized to bypass the blood-brain barrier, allowing for more effective concentration of drugs like analgesics, anesthetics, or chemotherapy agents in the central nervous system. By injecting the medication into the intrathecal space, it provides localized effects with potentially fewer systemic side effects compared to other routes of administration.

The other choices describe different methods of drug administration that do not involve the intrathecal space. For instance, injecting into the bloodstream refers to intravenous administration, while administering in the muscle pertains to intramuscular injections. Applying medication to the skin surface is indicative of topical administration. Each of these methods has distinct purposes and pharmacokinetics that differ significantly from intrathecal administration.