N-type voltage-gated calcium channels (Cav2.2) [1]
N-type calcium channels in rat brain membranes: Kd 1.1 pM (saturation binding), Kd 7 pM (kinetic analysis) [1]
Displacement of 125I-ω-MVIIA: IC50 2 pM, 7.2 pM, 29 pM [1]
Displacement of 125I-ω-GVIA: IC50 45 pM, 55 pM [1]
Inhibition of rat α1B-mediated calcium currents in Xenopus oocytes: IC50 0.4-11 nM depending on splice variant and β3 subunit [1]
Inhibition of native high-voltage-activated calcium currents in rat superior cervical ganglion neurons: IC50 32 nM, 90% inhibition [1]

Since ziconotide only partially decreases high-voltage activation in differentiated human neuroblastoma IMR32 cells, rat superior cervical ganglion neurons, and rat hippocampus neurons, this is because most native cells carry numerous distinct calcium channels. calcium flow. Moreover, ziconomide lessens the calcium currents that HEK cells, tsa-201 cells, and Xenopus laevis oocytes produce when the α1B subunit is expressed [1]. By lowering the release of pronociceptive neurotransmitters in the spinal cord's dorsal horn, ziconotide blocks pain signals and has antinociceptive effects [1].

---

Radioligand binding: ziconotide binds rapidly, reversibly, and with high affinity to N-type calcium channels in rat brain membranes and synaptosomes (Kd 1.1-9 pM) [1]
Electrophysiology: ziconotide inhibits N-type calcium currents in native cells (human neuroblastoma IMR32: 42% inhibition at 10 nM; rat superior cervical ganglion neurons: IC50 32 nM, 90% inhibition; rat hippocampal neurons: 30% inhibition at 3 μM) and heterologous expression systems (HEK cells expressing human α1B: 92% inhibition at 100 nM; tsa-201 cells expressing rat α1B: complete block by 100 nM; Xenopus oocytes expressing rat α1B: IC50 0.4-11 nM). The block shows little use-dependence. [1]
Neurotransmitter release: ziconotide inhibits depolarization-evoked norepinephrine release from rat hippocampus (IC50 ~0.5 nM), rat peripheral sympathetic efferent neurons (IC50 1.2 nM), and rat dorsal root ganglion neurons (IC50 63 nM). It also potently inhibits substance P release from rat spinal cord slices. [1]

In an experimental autoimmune mouse model of encephalomyelitis (EAE), IL-17 was produced in the spleen 25 days after EAE was triggered by MOG35-55 [2]. Ziconotide (it; 25-100 pmol/site; 5 μL; days 4, 10, 15, 20, and 24) similarly decreases IL-1β and IL-23 levels in the CNS.

---

Pre-clinical in vivo: ziconotide (intrathecal) produces potent and long-lasting antinociception in rat models of persistent and chronic pain. In the formalin model, bolus ID50 3 pmol for both phases; 2-day infusion (3 pmol/h) reduced phase I by 42.5% and phase II by 42.7%; 7-day infusion (3 pmol/h) reduced phase I by 20.4% and phase II by 59%. In the hot plate test, 8 pmol bolus increased withdrawal latency by 20%; continuous infusion (3 pmol/h) approximately doubled latency. In a paw incision model, 1 μg bolus (1 h pre-incision) prevented mechanical allodynia and heat hyperalgesia; post-incision ID50 <0.3 μg for allodynia and 0.1 μg for hyperalgesia. In inflammatory pain (CFA), bolus ID50 16 pmol for mechanical hyperalgesia. In neuropathic pain (spinal nerve ligation), bolus ID50 30-100 ng for mechanical allodynia; continuous infusion (10 ng/h for 3 days) ID50 for allodynia. In chronic constriction injury, 100 pmol bolus reversed heat hyperalgesia. ziconotide also shows efficacy when applied locally to sciatic nerve injury site (ID50 <1.0 μg) or microinjected into rostral ventromedial medulla (ID50 2.8 pmol). No tolerance develops during chronic administration. [1]
In EAE model (mouse): ziconotide (25, 50, 100 pmol/site i.t. on days 4,10,15,20,24 post-MOG35-55) reduced mechanical hypersensitivity (inhibition by 20±3%, 46±4%, 25±6% respectively, U-shaped curve) and thermal hyperalgesia (50 and 100 pmol: 35±10% inhibition, with 100 pmol significant; 50 pmol had p=0.0927). It failed to improve cognitive deficits (object location test), motor coordination (rotarod), clinical score, neurological severity score, or body weight loss. It reduced IL-1β and IL-23 in CNS, and IL-17 in spleen. It did not alter IL-10 levels. It reduced GFAP immunostaining in spinal cord but not Iba1 in brain. It partially reduced [18F]-FDG uptake in superior colliculi and cingulate cortex. Intravenous ziconotide (0.2 mg/kg every 3 days) reduced nociception and distance traveled (open field) but not other parameters. [2]

Radioligand binding assay: Binding of 125I-ω-MVIIA to N-type calcium channels in rat brain membranes or synaptosomes. Saturation binding gave Kd values of 1.1 pM (Stoehr and Dooley 1993) and 9 pM (Kristipati et al 1994). Kinetic analysis yielded Kd 7 pM and 18 pM respectively. Displacement experiments using 125I-ω-MVIIA gave IC50 values of 2 pM (Newcomb et al 1995), 7.2 pM (Wang et al 1998), and 29 pM (Lewis et al 2000). Displacement of 125I-ω-GVIA gave IC50 45 pM (Nielsen et al 1999b) and 55 pM (Lewis et al 2000). [1]

Electrophysiological assay (native cells): Inhibition of high-voltage-activated calcium currents in various native neuronal cells. In human neuroblastoma IMR32 cells, 10 nM ziconotide inhibited 42% of total calcium current (Fox 1995). In rat superior cervical ganglion neurons, ziconotide had an IC50 of 32 nM with 90% inhibition (Sanger et al 2000). In rat hippocampal neurons, 3 μM ziconotide inhibited 30% of total calcium current (Wen et al 2005). [1]
Electrophysiological assay (recombinant channels): Inhibition of recombinant α1B-mediated calcium currents in heterologous expression systems. In HEK cells expressing human α1B, 100 nM ziconotide caused 92% inhibition (Bleakman et al 1995). In HEK cells expressing rat α1B, IC50 was 72 nM (Sanger et al 2000). In tsa-201 cells expressing rat α1B, 100 nM produced complete block (Feng et al 2001). In Xenopus oocytes expressing rat α1B with different splice variants and β subunits, IC50 ranged from 0.4 to 11 nM (Lewis et al 2000). [1]
Neurotransmitter release assay: Depolarization-evoked norepinephrine release was measured in rat hippocampal slices, peripheral sympathetic efferent neurons, and dorsal root ganglion neurons. ziconotide inhibited norepinephrine release with IC50 values of ~0.5 nM (Newcomb et al 1995) and 5.5 nM (Wang et al 1998) in hippocampus; 1.2 nM in peripheral sympathetic efferent neurons (Wang et al 1998); 63 nM in dorsal root ganglion neurons (Smith et al 2002). Substance P release from rat spinal cord slices was also potently inhibited. [1]

Animal/Disease Models: Female C57BL/6 mice (18-22 g, 6-8 weeks old) injected with myelin oligodendrocyte glycoprotein [2]
Doses: 25 pmol/site, 50 pmol/site, 100 pmol /site
Route of Administration: intrathecal injection; results on days 4, 10, 15, 20 and 24: Dramatically diminished mechanical hypersensitivity in EAE animals.

---

Animal model of acute pain (formalin test) in rats: 5% formalin was injected into the rat paw. ziconotide was administered intrathecally as a single bolus (10 min before formalin) or by continuous infusion (2-day, 3-day, or 7-day infusion) prior to formalin. Bolus ID50 was 3 pmol for both phase I and phase II responses. For 2-day infusion, 3 pmol/h reduced phase I by 42.5% and phase II by 42.7%; 30 pmol/h reduced phase I by 61.2% and phase II by 86.0%. For 7-day infusion, 3 pmol/h reduced phase I by 20.4% and phase II by 59%; 30 pmol/h reduced phase I by 43.1% and phase II by 86.1%. [1]
Animal model of postoperative pain (paw incision) in rats: A bolus injection of ziconotide (1 μg) given 1 hour before incision prevented mechanical allodynia and heat hyperalgesia. Given 1 day post-incision, ID50 for mechanical allodynia was <0.3 μg and for heat hyperalgesia was 0.1 μg. [1]
Animal model of inflammatory pain (CFA) in rats: Complete Freund's adjuvant was injected into the hind paw. Five days later, an intrathecal bolus of ziconotide reversed mechanical hyperalgesia with an ID50 of 16 pmol. [1]
Animal model of neuropathic pain (spinal nerve ligation) in rats: L5/L6 spinal nerves were ligated. ziconotide was given as an intrathecal bolus (ID50 for mechanical allodynia: 1000 ng, 30-100 ng, or 320 ng/kg depending on study) or by continuous infusion (3-day infusion ID50 10 ng/h for mechanical allodynia). [1]
EAE model in mice: Female C57BL/6 mice were immunized subcutaneously with MOG35-55 peptide (200 μg) emulsified in CFA with M. tuberculosis, and injected intraperitoneally with pertussis toxin (300 ng) on days 0 and 2. ziconotide was administered intrathecally (25, 50, 100 pmol/site in 5 μL PBS) on days 4, 10, 15, 20, and 24 post-immunization. Control received PBS i.t. For intravenous administration, ziconotide (0.2 mg/kg) was injected via retro-orbital route every 3 days starting on day 7 (days 7,10,13,16,19,22,25). Behavioral tests included von Frey for mechanical hypersensitivity, hot plate for thermal nociception, object location test for spatial memory, rotarod for motor coordination, open field for locomotor activity, and clinical score (0-5 scale) and neurological severity score (0-8). Tissue was collected for cytokine ELISA (TNF, IL-1β, IFN-γ, IL-17, IL-23, CCL3, IL-10, leptin), histology (HE and LFB staining), immunohistochemistry (GFAP, Iba1), and microPET imaging with [18F]-FDG. [2]

Absorption, Distribution and Excretion
Intrathecal ziconovide administered 1 hour later at doses of 1 to 10 mcg yielded calculated AUC values of 83.6–608 ngh/mL and Cmax values of 16.4–132 ng/mL; these values are approximately dose-proportional. Due to intrathecal administration and the small molecular size resulting in low membrane permeability, ziconovide is expected to be primarily found in cerebrospinal fluid; plasma concentrations (if detected) remain stable for up to nine months post-administration. A small amount of intravenously administered ziconovide (<1%) is excreted in the urine. In patients receiving 1–10 mcg of ziconovide intrathecally within 1 hour, the calculated apparent volume of distribution was 155 ± 263 mL; this is approximately equivalent to the expected cerebrospinal fluid volume. Although intravenous administration is not recommended, the apparent volume of distribution after intravenous administration of 0.3–10 mcg/kg/day of ziconovide is 30,460 ± 6366 mL.
The cerebrospinal fluid clearance rate of ziconovide was 0.38 ± 0.56 mL/min, and the plasma clearance rate was 270 ± 44 mL/min.
The concentration of ziconovide in brain tissue reached its peak at 0.003% to 0.006% per gram of tissue injection 3–20 minutes after intravenous injection, decreasing to below 0.001%/g after 2 hours. ...The peptide was perfused via an in vivo dialysis probe implanted in the hippocampus. Image analysis and serial sections showed minimal diffusion of ziconovide in the extracellular fluid surrounding the dialysis probe; the peptide remained within 1 mm of the probe after 2 hours. ...In situ perfusion via the carotid artery also confirmed the drug's entry into the brain from the bloodstream. Compared to 14C inulin, the amount of radioactive material crossing the blood-brain barrier after perfusion of radioiodine-labeled ziconovide was statistically significantly higher.
The pharmacokinetics and pharmacodynamics of ziconotide were evaluated within 48 hours following intrathecal injection (1, 5, 7.5, or 10 μg) in 22 patients with chronic non-malignant pain. Plasma and cerebrospinal fluid (CSF) samples were collected within 24 hours. Analgesic effect was monitored using the Visual Analogue Scale for Pain Intensity (VASPI) and the Classification of Pain Relief Scale (CPRS). Pharmacokinetic (PK) parameters were calculated using a non-compartmental model. Plasma ziconotide data were insufficient for pharmacokinetic calculations. In CSF, the median half-life of ziconotide was 4.5 hours. The median CSF clearance and volume of distribution were 0.26 mL/min and 99 mL, respectively. CSF pharmacokinetics of ziconotide showed a linear relationship based on cumulative exposure and peak CSF concentration. Dose-related analgesia was observed. …
Intrathecal injection of ziconotide causes almost no systemic exposure. After entering systemic circulation from cerebrospinal fluid (CSF), ziconopeptide is expected to be degraded into peptide fragments and their constituent amino acids by endopeptidases and exopeptidases present in most organs. Ziconopeptide binds to human plasma proteins at a rate of approximately 50%. Following intrathecal injection of ziconopeptide, its mean volume of distribution (Vd) in CSF is close to the estimated total CSF volume (140 mL). For more complete data on the absorption, distribution, and excretion of ziconopeptide (6 items), please visit the HSDB record page. Metabolism/Metabolites Ziconopeptide is expected to be metabolized by various peptidases after entering systemic circulation; detailed information on ziconopeptide metabolism is not currently available. Following intrathecal injection, ziconopeptide is rapidly distributed and/or metabolized in the spinal CSF, followed by relatively rapid transport of metabolites from CSF to plasma. The relative contributions of intraspinal and extraspinal transport and intraspinal metabolism are unclear. However, there is evidence that ziconopeptide can be rapidly transported into the bloodstream, and its metabolism within the spinal cord may play an important role. Once in the bloodstream, the compound is rapidly metabolized through normal proteolytic mechanisms, ultimately breaking down into its constituent amino acids; it can be inferred that these amino acids will be further metabolized or integrated into proteins through normal physiological processes. Ziconopeptide is cleaved at multiple sites on its peptide chain by endopeptidases and exopeptidases. During continuous intrathecal administration, after ziconopeptide enters the systemic circulation from the cerebrospinal fluid, it is expected to be rapidly degraded into peptide fragments and its constituent free amino acids by proteolytic cleavage by various peptidases/proteases commonly found in most organs (e.g., kidneys, liver, lungs, muscles, etc.). In vitro studies have shown that the hydrolytic activity of ziconopeptide in human and animal cerebrospinal fluid and blood is extremely low. The bioactivity of the various expected proteolytic degradation products of ziconopeptide has not been evaluated.

---

Biological Half-Life
In patients who received intrathecal injections of 1–10 mcg of ziconopeptide within 1 hour, the calculated elimination half-life was 4.6 ± 0.9 hours. Although intravenous administration is not recommended, intravenous administration of ziconopeptide at doses of 0.3–10 mcg/kg/day results in an elimination half-life of 1.3 ± 0.3 hours. Following intrathecal administration, the terminal half-life of ziconopeptide in cerebrospinal fluid is approximately 4.6 hours (range 2.9–6.5 hours).

---

Pharmacokinetics in humans: Following intrathecal administration, the measured half-life (t1/2) of ziconotide in cerebrospinal fluid is approximately 4.5 hours, similar to the slow component of elimination observed in rats and monkeys. ziconotide was not detectable in the plasma of the majority of patients, indicating poor ability to cross the blood-brain barrier. [1]
Pharmacokinetics in animals: In rats and cynomolgus monkeys, the slow component of drug elimination was observed (Bowersox et al 1997). [1]

Effects During Pregnancy and Lactation
◉ Overview of Use During Lactation
Currently, there is no information on the clinical use of ziconopeptide during lactation. After intrathecal injection, ziconopeptide is usually undetectable or only detectable in very small amounts in plasma, and due to its molecular weight of 2639 Daltons, the concentration in breast milk may be very low. Furthermore, ziconopeptide is likely to be partially destroyed in the infant's gastrointestinal tract, and the amount absorbed by the infant may be minimal. If the mother needs to use ziconopeptide, breastfeeding should not be discontinued. Sedation of breastfed infants should be monitored, as sedation may lead to respiratory depression or feeding difficulties.
◉ Effects on Breastfed Infants
As of the revision date, no relevant published information was found.
◉ Effects on Lactation and Breast Milk
As of the revision date, no relevant published information was found.

---

Protein Binding
Zicoconopeptide binds to human plasma proteins at a rate of approximately 50%.

---

Interaction
Ziconovitide is a selective, potent, and reversible blocker of neuronal N-type voltage-sensitive calcium channels (VSCCs). Morphine is a μ-opioid receptor agonist that inhibits N-type VSCC channels via a G protein-coupled mechanism. Both drugs have analgesic effects when administered intrathecally (spinal cord). This study investigated the acute and chronic (7-day) interactions of intrathecal ziconovitide and morphine on nociceptive sensation in various animal models of pain. In the acute study, intrathecal administration of either morphine or ziconovitide alone dose-dependently inhibited formalin-induced tonic withdrawal and plantar pressure withdrawal responses. Combination administration of ziconovitide and morphine additively inhibited formalin-induced tonic withdrawal and significantly shifted the dose-response curve of morphine in the plantar pressure test to the left. Following chronic (7-day) intrathecal infusion, ziconovitide enhanced the analgesic effect of morphine in the formalin test. Conversely, chronic intrathecal morphine infusion can induce analgesia tolerance but does not affect the nociceptive effect of ziconovide. The analgesic effect of ziconovide alone is the same as that observed when ziconovide is co-administered with morphine in morphine-tolerant rats. In hot plate and tail dip tests, chronic intrathecal morphine infusion led to rapid tolerance, while ziconovide produced sustained analgesia without diminishing efficacy throughout the infusion. Although the co-administration of ziconovide and morphine produced significant synergistic analgesia in the initial phase of sustained infusion, it did not prevent the development of morphine analgesia tolerance. These results suggest that: (1) acute intrathecal ziconovide and morphine can produce additive or synergistic analgesia; (2) chronic intrathecal morphine infusion leads to analgesia tolerance but does not produce cross-tolerance to ziconovide; (3) long-term intrathecal ziconovide infusion does not produce tolerance or cross-tolerance to morphine analgesia; and (4) intrathecal ziconovide infusion does not prevent or reverse morphine tolerance. In clinical studies, ziconopeptide can be used in combination with anticonvulsants, antidepressants, antipsychotics, anxiolytics, and sedatives. It may interact with central nervous system depressants (increasing the incidence of adverse central nervous system reactions, such as dizziness, confusion, and decreased level of consciousness). Dosage adjustment or discontinuation of ziconopeptide or any concomitant central nervous system depressants may be necessary. It may also interact with antidepressants or anticonvulsants (increasing serum creatine kinase [CK, creatine phosphokinase, CPK]).

---

Adverse events in clinical trials: In Phase 3 trials, ziconotide was associated with dizziness, nystagmus, nausea, postural hypotension, somnolence, confusion, abnormal gait, ataxia, memory impairment, blurred vision, and sedation. Adverse events were more frequent in the ziconotide group than placebo. Their occurrence was reduced by initiating infusion at lower doses or using smaller/less frequent dose increments. Adverse events generally resolved upon dose reduction, slowing of dose escalation, or drug discontinuation. [1]
Therapeutic index: The therapeutic index of intrathecal ziconotide tends to be low. In animal studies, antinociceptive effects at higher doses are accompanied by motor deficits. It may cause hypotension if it enters systemic circulation due to inhibition of sympathetic neurotransmission. [1]
In EAE mouse model: ziconotide treatment (i.t. 50 pmol/site) did not cause significant adverse effects reported; however, it lacked efficacy on many parameters compared to CTK 01512-2. [2]

[1]. Ziconotide: a review of its pharmacology and use in the treatment of pain. Neuropsychiatr Dis Treat. 2007 Feb;3(1):69-85.

[2]. Beneficial Effects of the Calcium Channel Blocker CTK 01512-2 in a Mouse Model of Multiple Sclerosis. Mol Neurobiol. 2018 Dec;55(12):9307-9327.

Ziconotide (also known as SNX-111) is a neurotoxic peptide derived from the cone snail (Conus magus), composed of 25 amino acids and containing three disulfide bonds. Other similar peptides, collectively known as conotoxins, also exist, some of which have been shown to effectively bind to specific calcium channel subsets; ziconotide is used in part because its synthesis does not result in the loss of correct bonds or structural elements. Ziconotide is used to treat severe chronic pain unresponsive to other methods by inhibiting N-type calcium channels involved in nociceptive signaling. On December 28, 2004, ziconotide was approved by the U.S. Food and Drug Administration (FDA) and marketed by TerSera Therapeutics LLC. under the brand name Prialt. To date, ziconotide is the only calcium channel blocking peptide approved by the FDA. Ziconotide is a synthetic non-opioid multibasic peptide composed of 25 amino acids, an analogue of ω-conotoxin derived from the marine snail Conus magus, and possesses analgesic activity. Ziconovide appears to block neuronal N-type voltage-sensitive calcium channels (NCCBs), thereby inhibiting transmission from primary nociceptors in pain receptors. This drug may have significant analgesic effects on treatment-resistant pain.
See also: Ziconovide acetate (salt form).
Indications
Ziconovide is indicated for the treatment of patients with severe chronic pain unresponsive to other treatments and requiring intrathecal analgesia.
Ziconovide is indicated for the treatment of patients with severe chronic pain requiring intrathecal (IT) analgesia.
Mechanism of Action
Nociceptive pain signaling is a complex processing pathway involving peripheral nociceptors, primary afferent nerve fibers, and downstream central nervous system neurons in the spinal cord. Voltage-gated calcium channels (VGCCs) are important regulatory components of neural signaling, including N-type (Cav2.2) heteropolymer high-voltage calcium channels. Chronic pain, including inflammatory and neuropathic pain, typically involves the aberrant upregulation of voltage-gated calcium channel (VGCC) activity. This upregulation can be achieved through multiple cellular mechanisms and can lead to hyperalgesia and hyperalgesia. Specifically, activation of N-type channels is known to mediate the release of neurotransmitters substance P (SP), calcitonin gene-related peptide (CGRP), and glutamate in less myelinated Aδ and C fibers. These neurotransmitters affect downstream neural activation and pain perception. Furthermore, SP and CGRP can induce inflammation, potentially exacerbating pre-existing inflammatory chronic pain. Ziconotoxin, a neurotoxic peptide belonging to the ω-conotoxin class derived from the cone snail (Conus magus), inhibits N-type VGCCs. Although its exact mechanism is not fully elucidated, it is generally believed that ω-conotoxins act by directly blocking ion pores, preventing transmembrane transport of calcium ions. Further studies involving chimeric subunit expression and molecular modeling have shown that inserting the Met12 residue of ziconopeptide into the hydrophobic pocket formed by the Ile300, Phe302, and Leu305 residues of Cav2.2 enhances its binding affinity and may be associated with adverse toxicity. Ziconopeptide is an N-type calcium channel blocker (NCCB). Voltage-gated calcium channel (VSCC) transmission plays a crucial role in pain transmission. N-type VSCCs are present in high concentrations in dorsal root ganglion cells responsible for spinal cord pain processing. Ziconopeptide selectively and reversibly binds to and blocks these channels without interacting with other ion channels or cholinergic, monoaminergic, or μ and δ opioid receptors. Therefore, ziconopeptide inhibits spinal cord pain signal transduction.

---

Therapeutic Use
Ziconotide intrathecal injection is used to treat severe chronic pain in patients who cannot tolerate or cannot obtain adequate analgesia from other therapies (e.g., systemic analgesics, adjunctive therapy, intrathecal morphine therapy), especially in cases requiring intrathecal treatment.

---

Drug Warnings
/Black Box Warning/ Warning: Neuropsychiatric adverse reactions. Ziconotide is contraindicated in patients with a history of psychosis. Serious psychiatric symptoms and neurological dysfunction may occur during ziconotide treatment. All patients should be closely monitored for signs of cognitive impairment, hallucinations, or altered mood or consciousness. If severe neurological or psychiatric symptoms occur, ziconotide treatment should be discontinued. Meningitis has occurred in patients receiving ziconotide, primarily in patients treated via extracorporeal microinfusion devices and catheters. Meningitis may be due to accidental contamination of the microinfusion device or due to hematogenous or direct transmission of cerebrospinal fluid (e.g., from an infected pump or catheter access). Patients should be monitored for signs and symptoms of meningitis (e.g., fever, headache, neck stiffness, altered mental status, nausea or vomiting, seizures). Preparation of ziconopeptide solution and infusion of the drug reservoir should be performed by trained and qualified personnel under aseptic conditions. If meningitis is suspected (especially in immunocompromised patients) or confirmed, appropriate measures should be taken immediately (cerebrospinal fluid culture, anti-infective therapy, removal of the microinfusion device and catheter).
The use of Prialt has been associated with central nervous system-related adverse events, including psychiatric symptoms, cognitive impairment, and decreased alertness/slowed reaction time. In 1254 patients treated in clinical trials, the reported incidence of cognitive adverse events was as follows: confusion (33%), memory impairment (22%), speech impairment (14%), aphasia (12%), thought disorders (8%), and amnesia (1%). Cognitive impairment may gradually develop over several weeks of treatment. If signs or symptoms of cognitive impairment occur, the dose of Prialt should be reduced or the drug discontinued, but other possible causes should also be considered. The various cognitive effects of ziconovide are usually reversible within 2 weeks after discontinuation. The median recovery time for various cognitive effects is 3 to 15 days. Older adults (≥65 years) are at higher risk of confusion. Cognitive impairment (e.g., confusion, memory impairment, speech impairment, aphasia, thought disorders, amnesia) has been reported in patients treated with ziconovide. Cognitive impairment may develop gradually over several weeks and is usually reversible upon discontinuation. If cognitive impairment occurs, the dose of ziconovide should be reduced or discontinued; other possible causes of cognitive impairment should be considered. For more complete data on ziconovide (17 in total), please visit the HSDB record page.

---

Pharmacodynamics
Ziconovide inhibits N-type calcium channels involved in nociceptive signaling, primarily acting on the dorsal horn of the spinal cord. Although binding is reversible, caution should be exercised to ensure efficacy and minimize adverse reactions, and ziconovide has a narrow therapeutic window. Patients taking ziconopeptide may experience cognitive and neuropsychiatric symptoms, decreased level of consciousness, and elevated serum creatine kinase levels. Furthermore, ziconopeptide may increase the risk of infections, including severe meningitis. Patients who discontinue opioids upon starting ziconopeptide are advised to gradually reduce the dose.

---

ziconotide is marketed as Prialt® by Elan Pharmaceuticals. It is approved for the symptomatic management of severe chronic pain, particularly in patients refractory to morphine and for whom intrathecal therapy is viable. It is delivered via a programmable surgically implanted infusion pump (e.g., Medtronic SynchroMed EL, SynchroMed II, or CADD-Micro Ambulatory Infusion Pump) or an external microinfusion device. The dose is titrated incrementally. Prolonged administration does not lead to addiction or tolerance. [1]
In clinical trials (Phase 3): In cancer/AIDS patients (68 patients), continuous intrathecal infusion (0.1-2.4 or 0.4-7.0 μg/h for up to 6 days) provided average 53% reduction in VASPI pain scores with no loss of efficacy during maintenance. In non-malignant chronic pain (169 patients), average reduction 31%. In a third trial (220 patients) with slower titration (max 0.9 μg/h over 3 weeks), average improvement 15% and 24% less opioid consumption. In postoperative pain (18 patients, 0.7 or 7.0 μg/h for 48-72 h), significant pain relief and reduced morphine consumption. [1]
Open-label studies: In a patient with brachial plexus avulsion pain, continuous intrathecal infusion (0.3-3 ng/kg/h for 8 days) produced complete pain relief (pain score 85 mm to 0 mm). In neuropathic pain patients, intrathecal infusion over 1 hour (1-10 μg) produced dose-dependent analgesia lasting up to 48 hours. Single epidural doses (5-10 μg) produced significant pain relief. [1]
Recommended dosing: The manufacturer recommends a "start low, go slow" approach. Initiate infusion at ≤0.1 μg/h and titrate upwards no more frequently than 2-3 times per week to minimize adverse events. [1]

C102H172N36O32S7

2639.13408

2637.098

107452-89-1

Ziconotide acetate;914454-03-8;Ziconotide TFA

16135415

Typically exists as solid at room temperature

1.6±0.1 g/cm3

1.710

-17.05

42

46

40

177

5480

22

NCCCCC1NC(=O)CNC(=O)C(CCCCN)NC(=O)C(N)CSSCC2C(NC(C(NCC(NC(C(NC3C(NC(C(NC(C(NCC(NC(C(NC(C(=O)N)CSSCC(C(N2)=O)NC(=O)C(CC(=O)O)NC(=O)C(CC2=CC=C(O)C=C2)NC(=O)C(CCSC)NC(=O)C(CC(C)C)NC(=O)C(CCCNC(=N)N)NC(=O)C(CO)NC(=O)C(CSSC3)NC(=O)C(CCCCN)NC(=O)C(C)NC(=O)CNC1=O)=O)CCCCN)=O)=O)CO)=O)CCCNC(=N)N)=O)=O)CO)=O)=O)C(O)C)=O

BPKIMPVREBSLAJ-QTBYCLKRSA-N

InChI=1S/C102H172N36O32S7/c1-50(2)34-63-91(161)127-62(26-33-171-5)90(160)129-64(35-53-22-24-54(143)25-23-53)92(162)130-65(36-78(148)149)93(163)135-72-48-175-173-45-69(80(108)150)133-86(156)58(18-8-12-29-105)121-76(146)39-117-85(155)66(41-139)131-88(158)61(21-15-32-114-102(111)112)126-96(166)70-46-176-177-47-71(97(167)132-68(43-141)95(165)125-60(87(157)128-63)20-14-31-113-101(109)110)134-89(159)59(19-9-13-30-106)123-81(151)51(3)119-74(144)37-115-83(153)56(16-6-10-27-103)120-75(145)38-116-84(154)57(17-7-11-28-104)124-82(152)55(107)44-172-174-49-73(137-98(72)168)99(169)138-79(52(4)142)100(170)118-40-77(147)122-67(42-140)94(164)136-70/h22-25,50-52,55-73,79,139-143H,6-21,26-49,103-107H2,1-5H3,(H2,108,150)(H,115,153)(H,116,154)(H,117,155)(H,118,170)(H,119,144)(H,120,145)(H,121,146)(H,122,147)(H,123,151)(H,124,152)(H,125,165)(H,126,166)(H,127,161)(H,128,157)(H,129,160)(H,130,162)(H,131,158)(H,132,167)(H,133,156)(H,134,159)(H,135,163)(H,136,164)(H,137,168)(H,138,169)(H,148,149)(H4,109,110,113)(H4,111,112,114)/t51-,52+,55-,56-,57-,58-,59-,60-,61-,62-,63-,64-,65-,66-,67-,68-,69-,70-,71-,72-,73-,79-/m0/s1

2-[(1R,4S,7S,13S,16R,21R,24S,27S,30S,33S,36S,39S,42R,45S,48S,54S,60S,63R,68R,71S,77S)-63-amino-13,45,54,60-tetrakis(4-aminobutyl)-4,36-bis(3-carbamimidamidopropyl)-16-carbamoyl-71-[(1R)-1-hydroxyethyl]-7,39,77-tris(hydroxymethyl)-27-[(4-hydroxyphenyl)methyl]-48-methyl-33-(2-methylpropyl)-30-(2-methylsulfanylethyl)-2,5,8,11,14,23,26,29,32,35,38,41,44,47,50,53,56,59,62,69,72,75,78,85-tetracosaoxo-18,19,65,66,81,82-hexathia-3,6,9,12,15,22,25,28,31,34,37,40,43,46,49,52,55,58,61,70,73,76,79,84-tetracosazatricyclo[40.37.4.221,68]pentaoctacontan-24-yl]acetic acid

Zicontide Acetate

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

---

Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

View More

Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

---

Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

View More

Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

---

Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

---

 (Please use freshly prepared in vivo formulations for optimal results.)