What drugs can be given intrathecally for the treatment of pain?
Medications approved in the United States for intrathecal analgesia by the US Food and Drug Administration (FDA) include two drugs: morphine and ziconotide. Baclofen is FDA approved for intrathecal therapy for spasticity. It is common clinical practice to use other unapproved medications (e.g., other opioids and bupivacaine), and to mix different drugs together in an off-label manner. Theoretically, any soluble analgesic medication can be given intrathecally for the treatment of pain; however, many can be toxic to neural tissue and should be avoided, especially in higher doses and for chronic administration (e.g., ketamine). The Polyanalgesic Consensus Conference published guidelines on drugs, doses, and combinations considered appropriate for intrathecal analgesic therapy that can serve as a guide for practitioners. These recommended drugs are divided into first line, second line, third line, etc. agents and combinations based on clinical experience with efficacy and safety.