Source: FDA label
| Molecular formula | C102H172N36O32S7 |
|---|---|
| Molecular weight | 2639.2 g/mol |
| Registered trials | 14 |
| PubChem CID | 16135415 |
| Brand names | PRIALT |
Boxed warning: The FDA label for this compound includes a boxed warning, the FDA's strongest safety warning. See the full prescribing information for details.
Mechanism of Action
12.1 Mechanism of Action Ziconotide binds to N-type calcium channels located on the primary nociceptive (A-δ and C) afferent nerves in the superficial layers (Rexed laminae I and II) of the dorsal horn in the spinal cord. Although the mechanism of action of ziconotide has not been established in humans, results in animals suggest that its binding blocks N-type calcium channels, which leads to a blockade of excitatory neurotransmitter release from the primary afferent nerve terminals and antinoci
Living with severe chronic pain that no longer responds to standard analgesics can leave few options on the table. Ziconotide is one of the few therapies approved specifically for this narrow, difficult situation.
Key takeaways
- Ziconotide (brand name PRIALT) is FDA-approved for severe chronic pain managed through intrathecal infusion.
- It works by blocking N-type calcium channels involved in pain signal transmission in the spinal cord.
- The label carries a boxed warning.
- At least 14 clinical trials have studied ziconotide, including registry studies following real-world use.
- FAERS reports on ziconotide most often mention pain, device issues, and off-label use, alongside neuropsychiatric effects.
What Ziconotide Is
Ziconotide is an N-type calcium channel antagonist delivered directly into the intrathecal space around the spinal cord. Its label describes binding to calcium channels on primary nociceptive nerve fibers in the dorsal horn, the region of the spinal cord where pain signals are first relayed. This binding is thought to block the release of excitatory neurotransmitters from these nerve terminals, which in animal studies reduced pain signaling. The label notes that the precise mechanism has not been established in humans. The compound's PubChem entry (CID 16135415) reflects its identity as a complex peptide.
What Ziconotide Is Approved For
PRIALT is indicated for the management of severe chronic pain in adult patients for whom intrathecal therapy is warranted. It is intended for patients who are intolerant of, or refractory to, other treatments such as systemic analgesics, adjunctive therapies, or intrathecal morphine. The label carries a boxed warning, meaning prescribers are alerted to significant risks associated with the drug.
What the Evidence Shows
At least 14 clinical trials have registered ziconotide as a study drug. An early placebo-controlled Phase II/III study evaluated intrathecal SNX-111 (ziconotide) in cancer and AIDS patients with chronic pain and has since completed. More recent completed studies include patient registries tracking intrathecal ziconotide management in both the United States (PRIZM) and Europe, following how the therapy is used and tolerated outside of controlled trial settings.
Reported Side Effects
FAERS reports for ziconotide are led by pain (362 reports) and device issue (313), reflecting both the underlying condition being treated and the intrathecal pump delivery system. Off label use (301) and drug ineffective (241) reports are also common. Neuropsychiatric effects appear frequently, including confusional state (205), nausea (205), hallucination (168), and dizziness (157). These figures represent counts of submitted reports, not confirmed incidence rates or evidence of causation.
FAQ
What is ziconotide used for?
Ziconotide, sold as PRIALT, is approved for managing severe chronic pain in adults who need intrathecal therapy and have not tolerated or responded to other treatments like systemic analgesics or intrathecal morphine. It is delivered directly into the intrathecal space around the spinal cord rather than taken orally or injected into a vein.
How does ziconotide work?
Ziconotide blocks N-type calcium channels on nerve fibers in the spinal cord that carry pain signals. This blockade is thought to reduce the release of chemical messengers that transmit pain, based on animal studies, though the exact mechanism in humans has not been fully established.
Does ziconotide have a boxed warning?
Yes, the FDA label for ziconotide includes a boxed warning, which highlights serious risks that prescribers should be aware of before starting therapy.
What are the most commonly reported side effects of ziconotide?
FDA Adverse Event Reporting System data show pain, device issues, and off-label use as the most frequently reported terms, followed by drug ineffectiveness and neuropsychiatric effects such as confusional state, hallucination, and dizziness. These are counts of submitted reports and do not establish that ziconotide caused these events.
Has ziconotide been studied in clinical trials?
Yes, at least 14 clinical trials have registered ziconotide, including an early placebo-controlled study in cancer and AIDS patients with chronic pain and completed patient registries in the United States and Europe tracking real-world intrathecal use.
This page is an editorial information resource. It does not sell, prescribe, or recommend any medication.
Content is editorial information, not medical advice. Talk to your doctor before any treatment decision.
Sources: FDA label (DailyMed) FAERS ClinicalTrials.gov PubChem
Updated 2026-08-10