Ziconotide

] It was developed into an artificially manufactured drug by Elan Corporation. It was approved for sale under the name Prialt by the U.S. Food and Drug Administration on December 28, 2004, and by the European Commission on February 22, 2005.

Mechanism of action

The mechanism of ziconotide has not yet been discovered in humans. Results in animal studies suggest that ziconotide blocks the N-Type calcium channels on the primary nociceptive nerves in the spinal cord.

Therapeutic use

Due to the profound side effects or lack of efficacy when delivered through more common routes, such as orally or intravenously, ziconotide must be administered intrathecally (directly into the spine). As this is by far the most expensive and invasive method of drug delivery and involves additional risks of its own, [cite web |url=http://www.medscape.com/viewarticle/510621_7 |title=Medscape |accessdate=2007-12-21 |format= |work=] ziconotide therapy is generally considered appropriate (as evidenced by the range of use approved by the FDA in US) only for “management of severe chronic pain in patients for whom intrathecal (IT) therapy is warranted and who are intolerant of or refractory to other treatment, such as systemic analgesics, adjunctive therapies or IT morphine”.cite web |url=http://www.uspharmacist.com/index.asp?page=ce/10186/default.htm |title=U.S. Pharmacist |accessdate=2007-12-21 |format= |work=]

However, this must be weighed against the high level of pain management, both in terms of degree and length, and the apparent lack of tolerancecite journal |author=Prommer E |title=Ziconotide: a new option for refractory pain |journal=Drugs Today |volume=42 |issue=6 |pages=369–78 |year=2006 |pmid=16845440 |doi=10.1358/dot.2006.42.6.973534 |url=http://journals.prous.com/journals/servlet/xmlxsl/pk_journals.xml_summaryn_pr?p_JournalId=4&p_RefId=973534] and other signs of dependencecite journal |author=Klotz U |title=Ziconotide--a novel neuron-specific calcium channel blocker for the intrathecal treatment of severe chronic pain--a short review |journal=Int J Clin Pharmacol Ther |volume=44 |issue=10 |pages=478–83 |year=2006 |pmid=17063978 |doi=] even after extended treatment along with the need for alternatives to other therapies that have not worked for the patient. Ziconotide is also contraindicated for patients with certain preexisting mental disorders (e.g. psychosis) due to evidence that they are more susceptible to certain severe side effects. [ [https://www.prialt.com/downloads/product_information.pdf prialt.com] ]

Adverse reactions

The most common side effects are dizziness, nausea, confusion, and headache. Others may include weakness, hypertonia, ataxia, abnormal vision, anorexia, somnolence, unsteadiness on feet, and memory problems. The most severe, but rare side effects are hallucinations, thoughts of suicide, new or worsening depression, meningitis and seizures. Therefore, it is contraindicated in people with a history of psychosis, schizophrenia, clinical depression, and bipolar disorder.

Patents

The drug was patented by Neurex Corp., a U.S. company purchased in 1998 by Élan Corporation, plc of Ireland. U.S. patents assigned to Elan include 5,859,186, 5,795,864, 5,770,690, 5,587,454, and 5,559,095.

References

External links

* [http://www.PRIALT.com Manufacturer website]
* [http://www.sfgate.com/cgi-bin/article.cgi?f=/news/archive/2004/12/28/national1642EST0612.DTL&type=health FDA approves new drug for severe pain] , a December 2004 Associated Press article
* [http://www.elan.com/News/full.asp?ID=657731 Press release announcing FDA approval] from Elan
* [http://www.clinicaltrials.gov/ct/gui/show/NCT00076544 Ziconotide Effectiveness and Safety Trial in Patients with Chronic Severe Pain]