Ziconotide, a selective N-type voltage-sensitive calcium-channel blocker, approved for the intrathecal treatment of patients with severe chronic pain that is refractory to other treatment modalities, is the subject of a review in the Lancet. The following topics are covered:

• Pharmacology

• Analgesic efficacy

• Toxicity: adverse events with approved dose, toxic effects of high doses, rises in creatinine kinase, intrathecal catheter-associated complications, immunological reactions

• Typical opioid-induced adverse events

• Management of intolerable adverse events

• Switch from intrathecal opioids to intrathecal ziconotide

• Distribution, metabolism, elimination, and drug interactions

• Future developments