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Pain & neurology

Ziconotide

A cone-snail-venom-derived peptide painkiller given directly into spinal fluid for severe chronic pain.

L5Practice-changingApproved — narrow indicationApprovedHigh confidenceLast reviewed 2026-08-23
Intrathecal

Also known as: Prialt, SNX-111

Evidence passport

Last reviewed 2026-08-23

Evidence level
L5Practice-changing
Confidence
High confidence
Human efficacy
78/100
Human safety
70/100
Regulatory status
Approved — narrow indication
Development
Approved
Routes
Intrathecal
Evidence base
Includes human data
Furthest stage
Approved
Source curation
Sources fully curated
Clinical maturity
Approved specialist pain medicine

Overview

Human evidence78/100
Preclinical evidence70/100
Human safety evidence70/100

Clinical maturity: Approved specialist pain medicine

Routes & formulations

Studied / approved routes

Intrathecal

The approved product is delivered by intrathecal infusion from an implanted or external pump directly into the spinal fluid — the only approved route, and a clinical procedure managed by specialists. This registry provides no pump or dosing information.

Route availability is not evidence of efficacy, and evidence from one route does not transfer to another. The Registry never provides dosing or sourcing information.

Peptide lifecycle

  1. Discovery

  2. Preclinical

  3. Phase I

  4. Phase II

  5. Phase III

  6. Approved

Approved

What it is

A synthetic version of a peptide from cone-snail venom that blocks pain signalling in the spinal cord by closing N-type calcium channels.

What people claim

  • Relieves severe chronic pain in selected patients when other options fail

What the evidence actually says

Randomised controlled trials supported approval for its narrow intrathecal indication. It is also the clearest example in this registry of why route is part of the evidence: the same molecule is unmanageable systemically, and only works as a medicine because of where and how it is delivered.

Human evidence

  • Randomised, placebo-controlled intrathecal trials in severe chronic pain populations.

Preclinical evidence

  • Cone-snail conotoxin pharmacology and spinal analgesia models.

Animal and cell findings are Level 1–2 evidence.

Mechanism and pathways

  • Selective blockade of N-type calcium channels in dorsal-horn neurons interrupts pain transmission.

Safety and unknowns

  • Serious neuropsychiatric and neurological adverse effects are labelled; use is restricted to specialist intrathecal therapy with careful titration.
  • Systemic exposure is not the approved use and carries a different risk profile.

Cancer relevance

No concern identified

No established human cancer signal within approved use.

Regulatory status

FDA-approved (Prialt) for management of severe chronic pain in patients for whom intrathecal therapy is warranted and other treatments are inadequate or intolerable. Approval is specific to that intrathecal use in selected patients.

Evidence grade

L5Practice-changingHigh confidence

Replicated large randomised trials, pivotal Phase 3 programmes, or a major regulatory decision.

What would change our rating?

  • Not applicable at this evidence tier.

References and sources

Sources fully curated

Source hierarchy: regulatory documents and trial registries first, peer-reviewed work next, sponsor material flagged as non-independent. We never use supplier or clinic marketing as evidence, and where a verified source has not yet been curated we say so rather than inventing one.

Evidence change history

No recorded changes yet. Baseline position set on 2026-08-23.