Quick summary
Ziconotide (Prialt) is an FDA-approved peptide from cone snail venom and the only N-type calcium channel blocker approved for chronic pain. Delivered by intrathecal infusion, it provides potent non-opioid analgesia with no addiction liability.
Overview
Ziconotide (brand name: Prialt) is a synthetic 25-amino acid peptide derived from the omega-conotoxin MVIIA found in the venom of the predatory marine cone snail Conus magus. It is the first and only N-type calcium channel blocker approved for clinical pain management, receiving FDA approval in December 2004. Delivered by continuous intrathecal infusion via an implanted pump, Ziconotide provides potent analgesia in patients with severe chronic pain refractory to systemic analgesics and intrathecal morphine. It is non-opioid and carries no addiction liability.
Mechanism of action
Ziconotide selectively and reversibly binds to N-type voltage-sensitive calcium channels (Cav2.2) located on the presynaptic terminals of primary afferent nociceptive neurons in the dorsal horn of the spinal cord. By blocking calcium influx through these channels, Ziconotide inhibits the depolarization-evoked exocytotic release of pro-nociceptive neurotransmitters including glutamate, substance P, and calcitonin gene-related peptide (CGRP). This interrupts ascending pain signal transmission without affecting opioid receptors, rendering it effective in opioid-tolerant patients. Its 25-amino-acid structure contains three disulfide bridges forming a rigid, loop-constrained backbone that confers high channel selectivity. Cerebrospinal fluid (CSF) delivery is required because the peptide's size prevents oral or systemic bioavailability.
Dosing protocols
| Purpose | Route | Dosage | Frequency | Notes |
|---|---|---|---|---|
| severe chronic pain management (FDA-approved intrathecal) | intravenous | 0.5–19.2 mcg/day | continuous intrathecal infusion | Start at no more than 2.4 mcg/day; titrate by ≤2.4 mcg/day every 24 hours. Maximum approved dose: 19.2 mcg/day. Dose adjustments require specialist supervision. Slow titration minimizes psychiatric and neurological adverse events. |
Dosing information is for educational purposes only. Consult a qualified healthcare professional before using any peptide.
Research summary
Multiple randomized controlled trials (RCTs) established clinical efficacy. A pivotal double-blind RCT (Staats et al., 2004, JAMA) demonstrated a 31.2% reduction in visual analog scale (VAS) pain scores versus 6.0% for placebo in patients with refractory malignant or non-malignant pain. Additional trials confirmed efficacy in cancer pain, AIDS-related pain, and neuropathic pain. Long-term extension studies spanning up to 3 years show sustained analgesia without tolerance development. Narrow therapeutic index and significant CNS side effect burden at higher doses require careful dose titration under specialist supervision.[1][2][3][4]
Evidence grading
Each claimed benefit is graded by the strength of available evidence. Grades reflect study quality, not effect size.
Strong = multiple RCTs · Moderate = limited trials or observational · Preliminary = animal or in vitro only · Insufficient = anecdotal or no published data
Side effects
Side effects vary by individual. This is not an exhaustive list. Report unusual symptoms to a healthcare professional.
Common stacks
Peptides commonly paired with Ziconotide for synergistic effects.
Legal status
FDA-approved (NDA 021060, December 28, 2004) for management of severe chronic pain via intrathecal infusion. Prescription-only; requires implanted intrathecal drug delivery system. Available as Prialt 25 mcg/mL intrathecal solution. REMS program is not required but off-label use outside intrathecal route is not established.
Sourcing & access
Prescription required
Ziconotide is an FDA-approved prescription medication available through licensed healthcare providers, telehealth platforms, and 503A/503B compounding pharmacies.
Frequently asked questions
Ziconotide (brand name Prialt) is a synthetic 25-amino acid peptide derived from the omega-conotoxin MVIIA of the cone snail Conus magus. FDA-approved in December 2004, it is the first and only N-type calcium channel blocker for clinical pain management, delivered by intrathecal infusion.
Ziconotide selectively blocks N-type calcium channels (Cav2.2) on presynaptic nociceptive neurons in the spinal cord, inhibiting release of pain neurotransmitters including glutamate, substance P, and CGRP. It does not affect opioid receptors, making it effective in opioid-tolerant patients with no addiction liability.
Ziconotide has a narrow therapeutic index with significant CNS side effects at higher doses including dizziness, confusion, hallucinations, depression (boxed warning), somnolence, and ataxia. Meningitis risk exists from the intrathecal catheter. Careful dose titration under specialist supervision is required.
It is delivered by continuous intrathecal infusion via an implanted pump. Starting dose is no more than 2.4 mcg/day, titrated by no more than 2.4 mcg/day every 24 hours up to a maximum of 19.2 mcg/day. Oral or systemic delivery is not possible due to the peptide's size.
Research references
- Intrathecal ziconotide in the treatment of refractory pain in patients with cancer or AIDS: a randomized controlled trialPubMed
- A randomized, double-blind, placebo-controlled study of intrathecal ziconotide in adults with severe chronic painPubMed
- Long-term intrathecal ziconotide for chronic pain: an open-label studyPubMed
- Ziconotide: an update and reviewPubMed