Intrathecal Administration
Drug delivery directly into the cerebrospinal fluid via injection into the spinal canal. This route bypasses the blood-brain barrier and is used when central nervous system drug exposure is required. Some peptide-based therapies for neurological conditions use intrathecal delivery.
Technical Context
Intrathecal (IT) delivery bypasses the BBB by placing drug directly into the cerebrospinal fluid (CSF) via lumbar puncture or implanted pump/catheter systems. CSF volume is approximately 140mL and is completely exchanged every 6-8 hours. IT delivery achieves high CNS drug concentrations with minimal systemic exposure (reducing peripheral side effects). For peptide therapeutics, IT delivery has been explored for: neuroprotective peptides (targeting CNS pathology directly), analgesic peptides, and enzyme replacement therapies for lysosomal storage diseases. IT administration requires specialised clinical settings and carries risks including infection, headache, and inadvertent neural injury.