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
Key takeaways
- Ziconotide is FDA-approved under the brand name PRIALT for severe chronic pain managed with intrathecal therapy.
- It works by blocking N-type calcium channels that carry pain signals in the spinal cord.
- The label carries a boxed warning.
- Clinical research includes a completed Phase 3 trial and 14 total registered trials.
- Reported adverse events most often involve pain, neuropsychiatric symptoms, and device-related issues tied to the infusion system.
What Ziconotide Is
Ziconotide is a synthetic peptide classified as an N-type calcium channel antagonist. It is delivered directly into the spinal fluid through an intrathecal infusion system rather than taken by mouth or injected into a vein. According to its label, ziconotide binds to N-type calcium channels on nociceptive nerve fibers in the dorsal horn of the spinal cord. This binding is thought to block the release of excitatory neurotransmitters from pain-signaling nerve terminals, reducing pain transmission, though the exact mechanism in humans has not been fully established.
What Ziconotide Is Approved For
Ziconotide, sold as PRIALT, is approved for managing severe chronic pain in adults who require intrathecal therapy. It is intended for patients who have not tolerated or responded adequately to other treatments, including systemic analgesics, adjunctive therapies, or intrathecal morphine. The label carries a boxed warning, reflecting the need for careful clinical oversight when using this therapy.
What the Evidence Shows
Fourteen clinical trials involving ziconotide are registered. A completed Phase 3 trial, "Prialt (Ziconotide) In Severe Chronic Pain," evaluated the compound in this patient population. Additional research includes an ongoing observational study of PRIALT in clinical practice and a planned trial examining intrathecal ziconotide for chemotherapy-induced peripheral neuropathy.
Reported Side Effects
Adverse event reports for ziconotide most frequently describe pain and issues related to the intrathecal delivery device, reported 362 and 313 times respectively. Reports of off-label use and drug ineffectiveness were also common. Neuropsychiatric effects appear prominently, including confusional state and hallucination (205 and 168 reports), alongside nausea (205) 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, marketed as PRIALT, is approved for managing severe chronic pain in adults who need intrathecal therapy. It is generally used when patients have not responded to or cannot tolerate other treatments like systemic analgesics or intrathecal morphine.
How does ziconotide work?
Ziconotide blocks N-type calcium channels on nerve fibers that carry pain signals into the spinal cord's dorsal horn. This is thought to reduce the release of neurotransmitters involved in transmitting pain, though its exact mechanism in humans is not fully confirmed.
Does ziconotide have a boxed warning?
Yes, the FDA label for ziconotide includes a boxed warning. This signals that prescribers and patients should be aware of important safety considerations associated with its use.
What side effects have been reported with ziconotide?
The most commonly reported issues include pain, problems with the intrathecal infusion device, confusional state, hallucination, nausea, and dizziness. These come from adverse event reports, which reflect reported occurrences rather than confirmed rates or causes.
Is ziconotide still being studied in clinical trials?
Yes, ziconotide has 14 registered clinical trials, including a completed Phase 3 study in severe chronic pain. Newer research is exploring its use for chemotherapy-induced peripheral neuropathy.
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Content is editorial information, not medical advice. Talk to your doctor before any treatment decision.
Sources: FDA label (DailyMed) ClinicalTrials.gov FDA FAERS PubChem
Updated 2026-11-07