A new analgesic, ziconotide intrathecal infusion (Prialt) has been approved for patients who suffer from severe, chronic pain and require intrathecal therapy that cannot be relieved by morphine and other analgesics. It is a product of Elan Pharmaceuticals. The new medication works by targeting and blocking calcium channels on nerves that transmit pain signals.

Ziconotide is a human-made equivalent of a conopeptide found in the venom of the Conus magus snail, and has been shown in clinical trials to be effective in reducing pain for patients that failed all other therapies. Some patients were able to decrease the amount of narcotic that they took for chronic pain.

Patients with a preexisting history of psychosis should not be treated with ziconotide; severe psychiatric symptoms and neurologic impairment may occur during treatment with the medication. All patients should be monitored frequently for evidence of cognitive impairment, hallucinations, or changes in mood or consciousness.

The most frequently reported side effects associated with the drug in clinical trials were asthenia, nausea, vomiting, abnormal gait, ataxia, confusion, dizziness, memory impairment, nystagmus, abnormal vision, and urinary retention.