Ziconotide

Also known as: Prialt, SNX-111, omega-conotoxin MVIIA

A synthetic cone-snail toxin peptide that blocks N-type calcium channels, FDA-approved in 2004 as Prialt for intrathecal treatment of severe chronic pain.

Last updated October 26, 2026

Mechanism of Action

Ziconotide is a synthetic 25-amino-acid peptide identical to omega-conotoxin MVIIA from the venom of the marine cone snail Conus magus. It selectively blocks N-type voltage-gated calcium channels (Cav2.2) on primary afferent nerve terminals in the dorsal horn of the spinal cord, reducing release of pain neurotransmitters such as glutamate, substance P and CGRP. It does not act on opioid receptors, so it does not cause tolerance or respiratory depression, but it must be delivered directly into the cerebrospinal fluid because it does not cross the blood-brain barrier.

Half-life: ~4.6 hours in cerebrospinal fluid
Administration Routes: Intrathecal
Research Status: Clinical

Reported Benefits

FDA-approved for severe chronic pain in patients who need intrathecal therapy and are intolerant of or refractory to other treatments
Reduced pain scores versus placebo in randomized trials in cancer/AIDS pain and severe chronic non-malignant pain
Non-opioid mechanism without tolerance or respiratory depression

Potential Side Effects

Boxed warning: severe psychiatric symptoms and neurological impairment (confusion, hallucinations, depression, reduced consciousness)
Dizziness, nausea and nystagmus
Confusion, memory impairment and gait problems
Elevated creatine kinase
Meningitis risk related to the intrathecal catheter or pump

Common Dosing

Given only as a continuous intrathecal infusion through an implanted or external microinfusion pump, started at a low dose and titrated slowly over weeks because side effects are dose-related. Implantation, refills and titration are handled by pain-management specialists. Dosing is set and supervised by the prescribing clinician.

The dosing information above is aggregated from research literature and anecdotal community reports for educational purposes only. It is not a recommendation, prescription, or medical advice. Peptides are sold as research chemicals only and are not intended for human use.

Contraindications

Pre-existing history of psychosis
Contraindications to intrathecal therapy, such as infection at the infusion site, uncontrolled bleeding or spinal canal obstruction
Known hypersensitivity to ziconotide

No documented stacking partners for Ziconotide yet.

Intrathecal ziconotide in the treatment of refractory pain in patients with cancer or AIDS: a randomized controlled trial
2004
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A randomized, double-blind, placebo-controlled study of intrathecal ziconotide in adults with severe chronic pain
2006
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Intrathecal ziconotide in the treatment of chronic nonmalignant pain: a randomized, double-blind, placebo-controlled clinical trial
2006
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Yes. The FDA approved ziconotide as Prialt in December 2004 for intrathecal management of severe chronic pain. It is a prescription drug given only through an intrathecal pump under specialist care.

No. It blocks N-type calcium channels in the spinal cord rather than opioid receptors, so it does not cause opioid tolerance or respiratory depression. Its main limits are psychiatric and neurological side effects, which is why titration is slow.