Ziconotide (PRIALT; SNX-111) is a neuroactive peptide, which was approved by FDA in 2004 for the management of severe chronic pain in adult patients for whom intrathecal therapy is warranted, and who are intolerant of or refractory to other treatment, such as systemic analgesics, adjunctive therapies, or intrathecal morphine. Ziconotide acts as a selective N-type voltage-gated calcium channel blocker, which leads to a blockade of excitatory neurotransmitter release from the primary afferent nerve terminals.