Intratekal

Intratekal, or intrathecal, refers to administration into the intrathecal space of the spinal canal, where cerebrospinal fluid circulates around the spinal cord and nerve roots. This route provides direct access to the central nervous system, allowing drugs to act within the CSF or spinal cord and often permitting lower systemic exposure. The term is used in medical practice to describe injections, infusions, or implanted device–mediated delivery.

Delivery is typically via lumbar puncture for a single dose or through implanted systems such as intrathecal pumps or reservoirs for continuous or timed delivery. Catheter-based administration may also be used, including delivery into the cisternal or ventriculo-spinal compartments in selected cases. Procedures require strict asepsis, patient positioning, and monitoring for adverse effects, particularly respiratory or hemodynamic changes with certain drugs.

Indications include anesthesia and analgesia for spinal surgery or obstetric labor, management of chronic cancer-related pain, and relief of severe spasticity (notably with intrathecal baclofen). It is also used to deliver chemotherapeutic agents for leptomeningeal metastases and, in some regimens, reserve intrathecal administration for diagnostic testing or disease monitoring with specific agents such as methotrexate or cytarabine. In recent years, drugs like ziconotide have been approved for intrathecal use in chronic pain syndromes when other therapies fail.

Common intrathecal agents include opioids (morphine, fentanyl), local anesthetics (bupivacaine, lidocaine), baclofen for spasticity, and various chemotherapeutics. Liposomal cytarabine and other formulations extend exposure in the CSF. Preservative-free preparations are preferred to minimize inflammation.

Risks include infection, chemical or infectious meningitis, post-dural puncture headache, bleeding, nerve injury, catheter or pump complications, and systemic toxicity such as respiratory depression or hypotension with opioids. Careful patient selection, sterile technique, and ongoing monitoring are essential.