Intrathecal administration route

Intrathecal administration is a high-risk route of administration for medicines via an injection into the spinal canal. Medicines injected by the intrathecal route reach the cerebrospinal fluid (CSF) that surrounds the brain and spinal cord. Intrathecal administration can form part of chemotherapy treatment for some cancers, such as leukaemias or lymphomas. It may also be used in anaesthesia, infection and neurological disorders.

Unsafe medicines for intrathecal administration

Not all injectable medicines are safe for intrathecal administration. Inadvertent intrathecal administration of medicinal products, including muscle relaxants, local anaesthetics, opioids, antifibrinolytics, and chemotherapy, has led to severe harm. Harms include paralysis, spinal cord injury, seizures and death.

One of the most well-known types of chemotherapy that can cause death if inadvertently administered via the intrathecal route are the vinca alkaloids (vincristine, vinblastine, vindesine and vinorelbine). Vinca alkaloids are only suitable for intravenous administration. Further information on how to manage vinca alkaloids can be found in the SPS article on preventing harm from incorrect vinca alkaloid administration.

All NHS Trusts that provide an intrathecal chemotherapy service must comply with the national guidance on the safe administration of intrathecal chemotherapy (archived by the Department of Health) to protect patients. The SPS article on managing an intrathecal chemotherapy service provides more information.

Formulation suitability for intrathecal administration

When assessing the suitability of an injectable medicine for intrathecal administration, an injectable medicine that is licensed for intrathecal administration should be used where possible. Administration should be undertaken following the Summary of Product Characteristics (SmPC).

If considering a medicinal product that is not licensed for the intrathecal route, it is essential to assess its properties. The formulation may not be suitable for the intrathecal route due to its excipients, pH, osmolarity or endotoxin level. Giving an unsuitable formulation can increase the risk of infection, neurotoxicity or adverse effects.

The SPS article on choosing an injectable medicine for intrathecal administration and the SPS resource on intrathecal administration provide further information on making an informed risk assessment and assessing suitability for intrathecal administration.

Preparing and administering an intrathecal medicine

All medicines intended for intrathecal administration must be prepared and administered using dedicated neuraxial devices and connectors (NRFit™). These are specific syringes, needles and devices with safe connectors that will not connect to intravenous Luer connectors.

There is an NHS England National Patient Safety Alert – Transition to NRFit™ connectors for intrathecal and epidural procedures, and delivery of regional blocks that all NHS providers must comply with to ensure the risk of misconnection and wrong route error is reduced.

The physiochemical and microbiological stability of the injectable medicine and neuraxial syringe must be considered. The SPS article on shelf lives of aseptically prepared medicines in NRFit syringes provides more information.

Update history