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Heliyon May 2024Managing severe chronic pain is a challenging task, given the limited effectiveness of available pharmacological and non-pharmacological treatments. This issue continues... (Review)
Review
Managing severe chronic pain is a challenging task, given the limited effectiveness of available pharmacological and non-pharmacological treatments. This issue continues to be a significant public health concern, requiring a substantial therapeutic response. Ziconotide, a synthetic peptide initially isolated from in 1982 and approved by the US Food and Drug Administration and the European Medicines Agency in 2004, is the first-line intrathecal method for individuals experiencing severe chronic pain refractory to other therapeutic measures. Ziconotide produces powerful analgesia by blocking N-type calcium channels in the spinal cord, which inhibits the release of pain-relevant neurotransmitters from the central terminals of primary afferent neurons. However, despite possessing many favorable qualities, including the absence of tolerance development, respiratory depression, and withdrawal symptoms (largely due to the absence of a G-protein mediation mechanism), ziconotide's application is limited due to factors such as intrathecal administration and a narrow therapeutic window resulting from significant dose-related undesired effects of the central nervous system. This review aims to provide a comprehensive and clinically relevant summary of the literatures concerning the pharmacokinetics and metabolism of intrathecal ziconotide. It will also describe strategies intended to enhance clinical efficacy while reducing the incidence of side effects. Additionally, the review will explore the current efforts to refine the structure of ziconotide for better clinical outcomes. Lastly, it will prospect potential developments in the new class of selective N-type voltage-sensitive calcium-channel blockers.
PubMed: 38779019
DOI: 10.1016/j.heliyon.2024.e31105 -
Journal of Clinical Medicine Mar 2024Ziconotide is an intrathecal drug administered for the treatment of chronic pain. The current literature lacks an exhaustive benefit/risk assessment on this drug. We... (Review)
Review
BACKGROUND
Ziconotide is an intrathecal drug administered for the treatment of chronic pain. The current literature lacks an exhaustive benefit/risk assessment on this drug. We herein focus on Ziconotide's pharmacology and clinical applications.
METHODS
Literature research was conducted to identify studies on Ziconotide administration for the treatment of chronic pain, published between January 1990 and March 2023 and located via PubMed, Embase, Medline, Cinahl, and Web of Science, using the following keywords: Ziconotide, Omega conotoxin, Prialt, SNX-111, intrathecal therapy, and neuropathic pain. Only publications written in English were selected.
RESULTS
Among the 86 selected studies, we found 4 Randomized Controlled Trials (RCTs) and 3 prospective long-term studies concerning the intrathecal use of Ziconotide as a monotherapy in chronic pain. Other studies described the intrathecal infusion of Ziconotide combined with other drugs. Overall, Ziconotide has been proved to have strong efficacy for relieving chronic pain, although patients with co-morbid psychiatric disorders require a careful monitoring when treated with Ziconotide.
CONCLUSIONS
Overall, the use of Ziconotide, as a monotherapy or in conjunction with other therapies for the treatment of chronic pain, was reported to be efficacious. Overall, its use in patients with chronic pain refractory to other pharmacologic agents outweighs the possible adverse consequences, thus resulting in a favorable benefit/risk assessment.
PubMed: 38541869
DOI: 10.3390/jcm13061644 -
Neuromodulation : Journal of the... Jan 2024The aim of this study was to investigate the physicochemical stability of morphine-bupivacaine-ziconotide mixtures used in intrathecal analgesia in polypropylene...
OBJECTIVE
The aim of this study was to investigate the physicochemical stability of morphine-bupivacaine-ziconotide mixtures used in intrathecal analgesia in polypropylene syringes and intrathecal pumps.
MATERIALS AND METHODS
The stability study method was conceived according to International Council for Harmonisation guidelines. For propylene syringes, six different mixtures of morphine-bupivacaine and ziconotide were assessed over seven days. Two storage temperatures were tested (5 °C ± 3 °C and 25 °C ± 2 °C). For implantable pumps, nine different mixtures were assessed over 60 days and stored at 37 °C. Assays were performed using ultrahigh-pressure liquid chromatography. Turbidity and pH also were measured throughout the study.
RESULTS
Results confirmed excellent physicochemical stability for morphine and bupivacaine in the study for all conditions investigated (pumps at 37 °C, polypropylene syringes at 5 °C ± 3 °C and 25 °C ± 2 °C). Concerning ziconotide, after seven days, our study showed that every 95% confidence interval calculated had lower bounds >90% for all mixtures stored in polypropylene syringes. In implantable pumps, a decrease of the concentration was observed in all the mixtures studied. Moreover, the appearance of a degradation product confirmed the ziconotide degradation.
CONCLUSION
All results are in favor with a physicochemical stable preparation for six mixture profiles when stored in polypropylene syringes at 5 °C ± 3 °C and 25 °C ± 2 °C. For mixtures stored in implantable pumps, the efficacy should decrease over time owing to the degradation of ziconotide. A trade-off between high morphine concentration and increased refill interval will need to be found by clinicians.
PubMed: 38300172
DOI: 10.1016/j.neurom.2023.11.009 -
Proceedings of the National Academy of... Nov 2023Transmembrane Ca2.2 (N-type) voltage-gated calcium channels are genetically and pharmacologically validated, clinically relevant pain targets. Clinical block of Ca2.2...
Transmembrane Ca2.2 (N-type) voltage-gated calcium channels are genetically and pharmacologically validated, clinically relevant pain targets. Clinical block of Ca2.2 (e.g., with Prialt/Ziconotide) or indirect modulation [e.g., with gabapentinoids such as Gabapentin (GBP)] mitigates chronic pain but is encumbered by side effects and abuse liability. The cytosolic auxiliary subunit collapsin response mediator protein 2 (CRMP2) targets Ca2.2 to the sensory neuron membrane and regulates their function via an intrinsically disordered motif. A CRMP2-derived peptide (CBD3) uncouples the Ca2.2-CRMP2 interaction to inhibit calcium influx, transmitter release, and pain. We developed and applied a molecular dynamics approach to identify the dipeptide in CBD3 as the anchoring Ca2.2 motif and designed pharmacophore models to screen 27 million compounds on the open-access server ZincPharmer. Of 200 curated hits, 77 compounds were assessed using depolarization-evoked calcium influx in rat dorsal root ganglion neurons. Nine small molecules were tested electrophysiologically, while one (CBD3063) was also evaluated biochemically and behaviorally. CBD3063 uncoupled Ca2.2 from CRMP2, reduced membrane Ca2.2 expression and Ca currents, decreased neurotransmission, reduced fiber photometry-based calcium responses in response to mechanical stimulation, and reversed neuropathic and inflammatory pain across sexes in two different species without changes in sensory, sedative, depressive, and cognitive behaviors. CBD3063 is a selective, first-in-class, CRMP2-based peptidomimetic small molecule, which allosterically regulates Ca2.2 to achieve analgesia and pain relief without negative side effect profiles. In summary, CBD3063 could potentially be a more effective alternative to GBP for pain relief.
Topics: Rats; Animals; Chronic Pain; Rats, Sprague-Dawley; Peptidomimetics; Calcium; Calcium Channels, N-Type; Sensory Receptor Cells; Ganglia, Spinal
PubMed: 37972067
DOI: 10.1073/pnas.2305215120 -
Angewandte Chemie (International Ed. in... Jul 2023Ziconotide (ω-conotoxin MVIIA) is an approved analgesic for the treatment of chronic pain. However, the need for intrathecal administration and adverse effects have...
Ziconotide (ω-conotoxin MVIIA) is an approved analgesic for the treatment of chronic pain. However, the need for intrathecal administration and adverse effects have limited its widespread application. Backbone cyclization is one way to improve the pharmaceutical properties of conopeptides, but so far chemical synthesis alone has been unable to produce correctly folded and backbone cyclic analogues of MVIIA. In this study, an asparaginyl endopeptidase (AEP)-mediated cyclization was used to generate backbone cyclic analogues of MVIIA for the first time. Cyclization using six- to nine-residue linkers did not perturb the overall structure of MVIIA, and the cyclic analogues of MVIIA showed inhibition of voltage-gated calcium channels (Ca 2.2) and substantially improved stability in human serum and stimulated intestinal fluid. Our study reveals that AEP transpeptidases are capable of cyclizing structurally complex peptides that chemical synthesis cannot achieve and paves the way for further improving the therapeutic value of conotoxins.
Topics: Humans; omega-Conotoxins; Analgesics; Conotoxins; Calcium Channels; Calcium Channel Blockers
PubMed: 37148162
DOI: 10.1002/anie.202302812 -
British Journal of Pharmacology Jun 2024Neuropathic pain affects up to 10% of the global population and is caused by an injury or a disease affecting the somatosensory, peripheral, or central nervous system....
BACKGROUND AND PURPOSE
Neuropathic pain affects up to 10% of the global population and is caused by an injury or a disease affecting the somatosensory, peripheral, or central nervous system. NP is characterized by chronic, severe and opioid-resistant properties. Therefore, its clinical management remains very challenging. The N-type voltage-gated calcium channel, Ca2.2, is a validated target for therapeutic intervention in chronic and neuropathic pain. The conotoxin ziconotide (Prialt®) is an FDA-approved drug that blocks Ca2.2 channel but needs to be administered intrathecally. Thus, although being principally efficient, the required application route is very much in disfavour.
EXPERIMENTAL APPROACH AND KEY RESULTS
Here, we describe an orally available drug candidate, RD2, which competes with ziconotide binding to Ca2.2 at nanomolar concentrations and inhibits Ca2.2 almost completely reversible. Other voltage-gated calcium channel subtypes, like Ca1.2 and Ca3.2, were affected by RD2 only at concentrations higher than 10 μM. Data from sciatic inflammatory neuritis rat model demonstrated the in vivo proof of concept, as low-dose RD2 (5 mg·kg) administered orally alleviated neuropathic pain compared with vehicle controls. High-dose RD2 (50 mg·kg) was necessary to reduce pain sensation in acute thermal response assessed by the tail flick test.
CONCLUSIONS AND IMPLICATIONS
Taken together, these results demonstrate that RD2 has antiallodynic properties. RD2 is orally available, which is the most convenient application form for patients and caregivers. The surprising and novel result from standard receptor screens opens the room for further optimization into new promising drug candidates, which address an unmet medical need.
Topics: Animals; Humans; Male; Mice; Rats; Administration, Oral; Calcium Channel Blockers; Calcium Channels, N-Type; Dose-Response Relationship, Drug; Mice, Inbred C57BL; Neuralgia; omega-Conotoxins; Rats, Inbred Lew
PubMed: 38157867
DOI: 10.1111/bph.16309 -
Pharmacological Research Feb 2024Chronic pain is a complex and challenging medical condition that affects millions of people worldwide. Understanding the underlying mechanisms of chronic pain is a key... (Review)
Review
Chronic pain is a complex and challenging medical condition that affects millions of people worldwide. Understanding the underlying mechanisms of chronic pain is a key goal of preclinical pain research so that more effective treatment strategies can be developed. In this review, we explore nociception, pain, and the multifaceted factors that lead to chronic pain by focusing on preclinical models. We provide a detailed look into inflammatory and neuropathic pain models and discuss the most used animal models for studying the mechanisms behind these conditions. Additionally, we emphasize the vital role of these preclinical models in developing new pain-relief drugs, focusing on biologics and the therapeutic potential of NMDA and cannabinoid receptor antagonists. We also discuss the challenges of TRPV1 modulation for pain treatment, the clinical failures of neurokinin (NK)- 1 receptor antagonists, and the partial success story of Ziconotide to provide valuable lessons for preclinical pain models. Finally, we highlight the overall success and limitations of current treatments for chronic pain while providing critical insights into the development of more effective therapies to alleviate the burden of chronic pain.
Topics: Animals; Humans; Chronic Pain; Neuralgia; Pain Management; Models, Animal; Research
PubMed: 38232910
DOI: 10.1016/j.phrs.2024.107073 -
Neuromodulation : Journal of the... Aug 2023This study aimed to investigate the physicochemical stability of morphine-ropivacaine-ziconotide mixtures used in intrathecal analgesia.
PURPOSE
This study aimed to investigate the physicochemical stability of morphine-ropivacaine-ziconotide mixtures used in intrathecal analgesia.
MATERIALS AND METHODS
Eight mixtures were studied to assess their stability profiles according to the initial drug concentrations used. The solutions obtained were put in implantable pumps and stored at 37 °C over a period of 60 days. Assays were performed using ultra high-pressure liquid chromatography. Turbidity and pH were also measured throughout the study.
RESULTS
Results confirmed excellent physicochemical stability for morphine and ropivacaine. Concerning ziconotide, three of the eight mixtures did not show any sign of chemical instability: average concentrations remained constant throughout the 60 days. A decrease of the concentration was observed for the five other mixtures. Moreover, the appearance of a degradation product linked to oxidation confirmed the ziconotide degradation.
CONCLUSIONS
All these results are in favor of a physicochemical stable preparation for three of the mixture profiles when stored in implantable pumps at 37 °C up to 60 days. For the five others, the efficacy should decrease over time owing to the degradation of ziconotide. The decrease in kinetics of the ziconotide concentration depends on the mixing profile. One possibility is to adapt the filling intervals according to the profile of the mixture. Finally, the results show the period of stability ensuring maximum analgesic efficacy for the eight mixture profiles studied.
Topics: Humans; Ropivacaine; Morphine; Analgesics; omega-Conotoxins; Injections, Spinal; Analgesics, Non-Narcotic
PubMed: 35088750
DOI: 10.1016/j.neurom.2021.10.002 -
Neuromodulation : Journal of the... Aug 2023Recent recommendations on starting dose, smaller dose increments, and longer intervals between dose increase have the potential to increase the safety of ziconotide...
OBJECTIVES
Recent recommendations on starting dose, smaller dose increments, and longer intervals between dose increase have the potential to increase the safety of ziconotide administration in addition to improving its value for money. Ziconotide is not routinely commissioned in England, with one of the concerns being whether it represents the best use of resources. The aim of this project is to conduct a budget impact analysis to estimate the costs or savings associated with the changes in ziconotide dosage in addition to its use in combination with morphine for the management of cancer pain.
MATERIALS AND METHODS
An open, Markov-like cohort decision analytic model was developed to estimate the budget impact of ziconotide in combination with morphine (ziconotide combination therapy) vs morphine monotherapy through intrathecal drug delivery (ITDD) for the management of cancer pain. The perspective adopted was that of the UK National Health Service, with a five-year time horizon. Sensitivity analyses were conducted to evaluate different scenarios.
RESULTS
Ziconotide combination therapy was more expensive than treatment with morphine monotherapy. The total costs of ziconotide combination therapy and morphine monotherapy for the first year were £395,748 and £136,628 respectively. The estimated five-year cumulative budget impact of treatment with ziconotide combination therapy for the five-year time horizon was £2,487,539, whereas that of morphine monotherapy was £913,804. The additional costs in any of the first five years are below the resource impact significance level of £1 million for medical technologies in England.
CONCLUSIONS
The results of this budget impact analysis suggest that although a combination of intrathecal ziconotide in combination with morphine is associated with higher costs to the health care system in England, the incremental costs are not significant. Routine commissioning of ziconotide alone or in combination with morphine would provide an alternative for a population with limited ITDD treatment options.
Topics: Humans; Cancer Pain; State Medicine; Analgesics, Non-Narcotic; Morphine; omega-Conotoxins; Injections, Spinal; Neoplasms
PubMed: 36202713
DOI: 10.1016/j.neurom.2022.08.458