Ziprasidone

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Ziprasidone
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Systematic (IUPAC) name
5-[2-[4-(1,2-benzisothiazol-3-yl)-1-piperazinyl]ethyl]-
6-chloro-1,3-dihydro-2H-indol-2-one
Clinical data
[[Regulation of therapeutic goods |Template:Engvar data]]
Pregnancy
category
  • US: C (Risk not ruled out)
Routes of
administration
oral, intramuscular
Legal status
Legal status
  • ℞ (Prescription only)
Pharmacokinetic data
Bioavailability 100% (intramuscular)
60% (orally)
Metabolism hepatic (aldehyde reductase)
Biological half-life 7 hours
Excretion Urine and feces
Identifiers
CAS Number 146939-27-7
ATC code N05AE04 (WHO)
PubChem CID 60854
IUPHAR/BPS 59
DrugBank DB00246
ChemSpider 54841
Chemical data
Formula C21H21ClN4OS
Molar mass 412.936[[Script error: No such module "String".]]
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Ziprasidone (marketed as Geodon, Zeldox by Pfizer) was the fifth atypical antipsychotic to gain FDA approval (February 2001). In the United States, Ziprasidone is Food and Drug Administration (FDA) approved for the treatment of schizophrenia, and the intramuscular injection form of ziprasidone is approved for acute agitation in schizophrenic patients. Ziprasidone has also received approval for acute treatment of mania and mixed states associated with bipolar disorder. The brand name Geodon has been suggested to bring to mind the phrase 'down (don) to earth (geo)' referring to the goals of the medication.

The oral form of ziprasidone is the hydrochloride salt, ziprasidone hydrochloride. The intramuscular form, on the other hand, is the mesylate salt, ziprasidone mesylate trihydrate, and is provided as a lyophilized powder.

Geodon was one of four drugs which Pfizer in 2009 pleaded guilty to misbranding "with the intent to defraud or mislead". Pfizer agreed to pay $2.3 billion (£1.4 billion) in settlement, and entered a corporate integrity agreement. Pfizer was found to have illegally promoted four of its drugs for use in conditions that had not been approved by the FDA.[1]

Pharmacology

Ziprasidone has a high affinity for dopamine, serotonin, and alpha-adrenergic receptors and a moderate affinity for histamine receptors, where it is believed to act as an antagonist.[2] Ziprasidone also displays some inhibition of synaptic reuptake of serotonin and norepinephrine[2][3], although the clinical significance of this is unknown. The mechanism of action of ziprasidone is unknown. However it has been theorized that its antipsychotic activity is mediated primarily by antagonism at dopamine receptors, specifically D2. Serotonin antagonism may also play a role in the effectiveness of ziprasidone, but the significance of 5-HT2A antagonism is debated among researchers.[4] Ziprasidone has perhaps the most selective affinity for 5-HT2A receptors relative to D2 and 5-HT2C receptors of any neuroleptic.[5][6] Antagonism at histaminic and alpha adrenergic receptors likely explains some of the side effects of ziprasidone, such as sedation and orthostasis.

Pharmacokinetics

The systemic bioavailability of ziprasidone administered intramuscularly is 100%, or 60%, administered orally with food. After a single dose intramuscular administration, the peak serum concentration typically occurs at about 60 minutes after the dose is administered, or earlier. Steady state plasma concentrations are achieved within one to three days. The mean half-life ranges from two to five hours. Exposure increases in a dose-related manner and following three days of intramuscular dosing, little accumulation is observed.

Ziprasidone absorption is not optimally achieved when administered without food. Without a meal preceding dose, the bioavailability of the drug is reduced by approximately 50%.[7][8]

Ziprasidone is hepatically metabolized by aldehyde oxidase; minor metabolism occurs via cytochrome P450 3A4 (CYP3A4).[9] Medications that induce (e.g. carbamazepine) or inhibit (e.g. ketoconazole) CYP3A4 have been shown to decrease and increase, respectively, blood levels of ziprasidone.[10][11]

Adverse effects

Ziprasidone received a black box warning due to increased mortality in elderly patients with dementia-related psychosis.[7] It also slightly increases the QTc interval in some patients and increases the risk of a potentially lethal type of heart arrhythmia known as torsades de pointes. Ziprasidone should be used cautiously in patients taking other medications likely to interact with ziprasidone or increase the QTc interval.[12]

Ziprasidone is known to cause activation into mania in some bipolar patients.[13][14][15]

This medication can cause birth defects, according to animal studies, although this side effect has not been confirmed in humans.[7]

Adverse events reported for ziprasidone include severe chest pains, impaired erectile function and stimulation, sedation, insomnia, orthostasis, life-threatening neuroleptic malignant syndrome, akathisia, and the development of permanent neurological disorder tardive dyskinesia. Rarely, temporary speech disorders may result.

Recently, the FDA required the manufacturers of some atypical antipsychotics include a warning about the risk of hyperglycemia and Type II diabetes with atypical antipsychotics. Some evidence suggests that ziprasidone may not be as bad as some of the other atypical antipsychotics (namely, olanzapine (Zyprexa)) at causing insulin resistance and weight gain.[16][17][18][19] In fact, in a trial of long term therapy with ziprasidone, overweight patients (BMI > 27) actually had a mean weight loss overall.[7] Ziprasidone, though, is not a weight loss drug. The weight loss reflected in this study on ziprasidone was really reflective of patients who had gained weight on other antipsychotics who were now trending back toward their baseline.[citation needed] According to the manufacturer insert, ziprasidone caused an average weight gain of 2.2 kg (4.8 lbs) (which is significantly lower than other atypicals–clozapine and olanzapine).

Off-label uses

In addition to its antipsychotic use, ziprasidone is sometimes prescribed for the treatment of tic disorders. A small study[20] has supported the efficacy of this use.

References

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External links

de:Ziprasidon

hu:Ziprazidon pt:Ziprasidona ru:Зипрасидон

sv:Ziprasidon
  1. "Pfizer agrees record fraud fine". BBC News. British Broadcasting Corporation. 2 September 2009. 
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  5. Marek GJ, Carpenter LL, McDougle CJ, Price LH (2003). "Synergistic action of 5-HT2A antagonists and selective serotonin reuptake inhibitors in neuropsychiatric disorders". Neuropsychopharmacology. 28 (2): 402–12. doi:10.1038/sj.npp.1300057. PMID 12589395. 
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  7. 7.0 7.1 7.2 7.3 "Geodon Prescribing Information" (PDF). Pfizer, Inc. Retrieved 2009-01-26. 
  8. Miceli JJ, Glue P, Alderman J, Wilner K (2007). "The effect of food on the absorption of oral ziprasidone". Psychopharmacol Bull. 40 (3): 58–68. PMID 18007569. 
  9. Sandson NB, Armstrong SC, Cozza KL (2005). "An overview of psychotropic drug-drug interactions". Psychosomatics. 46 (5): 464–94. doi:10.1176/appi.psy.46.5.464. PMID 16145193. 
  10. Miceli JJ, Anziano RJ, Robarge L, Hansen RA, Laurent A (2000). "The effect of carbamazepine on the steady-state pharmacokinetics of ziprasidone in healthy volunteers". Br J Clin Pharmacol. 49 Suppl 1: 65S–70S. doi:10.1046/j.1365-2125.2000.00157.x. PMC 2015057Freely accessible. PMID 10771457. 
  11. Miceli JJ, Smith M, Robarge L, Morse T, Laurent A (2000). "The effects of ketoconazole on ziprasidone pharmacokinetics--a placebo-controlled crossover study in healthy volunteers". Br J Clin Pharmacol. 49 Suppl 1: 71S–76S. doi:10.1046/j.1365-2125.2000.00156.x. PMC 2015056Freely accessible. PMID 10771458. 
  12. {{cite web Patients in general will experience loss of focus and motivation as well as blurry vision to the point that stronger doses may cause thoughts of suicide while the medicine is in the patients system. Thoughts of suicide may occur. Typically side effects will start about an hour after ingestion and peak about four to five hours after ingestion. Patient will most likely be unable to operate machinery or drive a vehicle while the medicine is effecting the patient as blurred vision can be quite severe. Ziprasidone may cause cause dangerous—even fatal—heartbeat irregularities. Geodon generally adheres to the mid section of the prefrontal cortex. It derives from the ideas and thoughts process in the prefrontal cortex in which determines a treatment diagnosis for psychosis. Those who experience the symptoms of psychosis will experience on-going symptoms such as: lack of sleep, insomnia, and uncontrollable desires and experiences. Geodone adheres and corrects the prefrontal cortex by delivering an enzyme called (enzyme-B). This enzyme corrects the basal ganglia function which coorelates with the B-cortex hemispheres. In other words the enzyme delivers a vital nutrient into the system which is release by the geodome once again, called enzyme-b. The process of Geodon is somewhat confusing as it affects both the basal ganglia and prefrontal cortex. By affecting the basal ganglia the prefrontal cortex does what is called: identity change. This is a process in which enzymes are switched from one section of the brain to another. The prefrontal cortex is mainly involved in spacial recognition which will be slightly alleviated by the geodon. Those who experience spacial recognition problems usually suffer from psychosis. |url=http://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm170899.htm |work=MedWatch |title=Geodon (ziprasidone HCl) Dear Healthcare Professional Letter, Mar 2002 |publisher=Food and Drug Administration |accessdate=2009-08-03}}
  13. CF Baldassano, C Ballas, SM Datto, D Kim, L Littman, J O'Reardon, MA Rynn (2003). "Ziprasidone-associated mania: a case series and review of the mechanism". Bipolar Disord. 5 (1): 72–75. doi:10.1034/j.1399-5618.2003.02258.x. PMID 12656943. 
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  19. Newcomer JW (2005). "Second-generation (atypical) antipsychotics and metabolic effects: a comprehensive literature review". CNS Drugs. 19 Suppl 1: 1–93. PMID 15998156. 
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