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pimozide

 
Dictionary: pim·o·zide   (pĭm'ə-zīd') pronunciation
n.
An antipsychotic drug, C28H29F2N3O, used in the treatment of chronic schizophrenia and in the management of Tourette's syndrome.

[PI(PERIDINE) + moz- (shortening and alteration of IMIDAZOLE) + -IDE.]


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Dental Dictionary: pimozide
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n

trade name: Orap; drug class: antipsychotic, antidyskinetic; action: blocks dopamine effects on central nervous system; uses: motor and phonic tics in Giles de la Tourette’s syndrome.

Drug Info: Pimozide
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Brand names: Orap®

Chemical formula:



Pimozide tablets

What are pimozide tablets?

PIMOZIDE (Orap®) helps to lessen the muscle and speech tics that are caused by Tourette's syndrome. Pimozide can also treat conditions that may cause you to hear or see things that others do not. Generic pimozide tablets are not yet available.

What should I tell my health care provider before I take this medicine?

They need to know if you have any of these conditions:
• an alcohol abuse problem
• blood disease
• cancer
• difficulty urinating
• glaucoma
• heart, kidney, or liver disease
• low potassium or magnesium levels in your blood
• Parkinson's disease
• prostate trouble
• seizures (convulsions)
• an unusual or allergic reaction to pimozide, other medicines, foods, dyes, or preservatives
• pregnant or trying to get pregnant
• breast-feeding

How should I take this medicine?

Take pimozide tablets by mouth with or without food. Follow the directions on the prescription label. Swallow the tablets with a drink of water. If pimozide upsets your stomach you can take it with food. Take your doses at regular intervals. Do not take your medicine more often than directed. Do not stop taking except on your prescriber's advice. Do not drink alcoholic beverages or grapefruit juice products while taking pimozide.

Contact your pediatrician or health care professional regarding the use of this medicine in children. Special care may be needed.

Patients over age 65 years may have a stronger reaction to this medicine and need smaller doses.

What drug(s) may interact with pimozide?

Pimozide has the potential to interact with many medications. The list below contains some of the drugs that can interact:

Do not take pimozide with any of the following medications:
aprepitant
astemizole
bepridil
• certain antibiotics: clarithromycin, dirithromycin, erythromycin, gatifloxacin, grepafloxacin, moxifloxacin, sparfloxacin, or troleandomycin
cimetidine
cisapride
diltiazem
dolasetron
• grapefruit juice
halofantrine
• medicines for fungal infections (examples- fluconazole, itraconazole, ketoconazole, voriconazole)
• medicines for treating HIV virus infection or AIDS (examples- amprenavir, indinavir, nelfinavir, saquinavir, ritonavir)
mefloquine
mibefradil
nicardipine
probucol
quinine
• some medicines for treating depression or other mental problems (examples- amoxapine, fluoxetine, fluvoxamine, maprotiline, nefazodone, paroxetine, sertraline, ziprasidone)
• some medicines for treating heart-rhythm problems (examples- amiodarone, flecainide, disopyramide, dofetilide, ibutilide, procainamide, quinidine, sotalol)
tacrolimus
terfenadine
verapamil
zileuton

Pimozide may also interact with the following medications:
• barbiturates, like phenobarbital
bosentan
carbamazepine
ciprofloxacin
citalopram
• enoxacin
• isoniazid (INH)
levodopa
• medicines for sleep or anxiety
• medicines for treating seizures
norfloxacin
• pain relievers
paroxetine
rifampin
sertraline
• some medicines for treating asthma
• some medicines for treating pain
tacrine

Tell your prescriber or health care professional about all other medicines you are taking, including non-prescription medicines. Also tell your prescriber or health care professional if you are a frequent user of drinks with caffeine or alcohol, if you smoke, or if you use illegal drugs. These may affect the way your medicine works. Check with your health care professional before stopping or starting any of your medicines.

What should I watch for while taking pimozide?

Visit your prescriber or health care professional for regular checks on your progress. It may be several weeks before you see the full effects of pimozide. Do not suddenly stop taking pimozide. You may need to gradually reduce the dose. Only stop taking pimozide on your prescriber's advice.

You may get dizzy or drowsy. Do not drive, use machinery, or do anything that needs mental alertness until you know how pimozide affects you. Alcohol can increase dizziness and drowsiness. Avoid alcoholic drinks.

Do not drink grapefruit juice products while taking pimozide. An ingredient in grapefruit juice can increase the chance of developing serious heart problems from pimozide.

If you are going to have surgery tell your prescriber or health care professional that you are taking pimozide.

What side effects may I notice from taking pimozide?

Side effects that you should report to your prescriber or health care professional as soon as possible:
• change in emotion or behavior such as feeling depressed, angry, or anxious
• change in vision
• difficulty breathing
• difficulty swallowing
• fast, slow or irregular heartbeat (palpitations)
• fever
• inability to control muscle movements in the face, hands, arms, or legs
• increased thirst
• loss of balance or difficulty walking
• menstrual changes
• rash
• restlessness or need to keep moving
• seizures
• stiff muscles or jaw
• seizures
• sexual difficulties
• skin rash
• spasms of the face, tongue, or mouth
• tremors or trembling
• uncontrollable tongue or mouth movements

Side effects that usually do not require medical attention (report to your prescriber or health care professional if they continue or are bothersome):
Less common:
• changes in sexual desire
• constipation
• difficulty sleeping
• difficulty urinating
• excessive watering or drooling of mouth
• headache
• nausea or vomiting
• trouble in controlling urine
• weight gain
More Common:
• dizziness; especially on standing from a sitting or lying postion
• drowsiness
• dry mouth
• weight loss

Where can I keep my medicine?

Keep out of the reach of children in a container that small children cannot open.

Store at room temperature between 20 degrees and 25 degrees C (68 degrees and 77 degrees F). Throw away any unused medicine after the expiration date.

Last updated: 7/1/2002

Important Disclaimer: The drug information provided here is for educational purposes only. It is intended to supplement, not substitute for, the diagnosis, treatment and advice of a medical professional. This drug information does not cover all possible uses, precautions, side effects and interactions. It should not be construed to indicate that this or any drug is safe for you. Consult your medical professional for guidance before using any prescription or over the counter drugs.

Veterinary Dictionary: pimozide
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An antipsychotic agent in humans; used for its long-acting central antiemetic effect in dogs.

Wikipedia: Pimozide
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Pimozide
Systematic (IUPAC) name
1-[1-[4,4-bis(4-fluorophenyl)butyl]-
4-piperidinyl]-1,3-dihydro-
2
H-benzimidazole-2-one
Identifiers
CAS number 2062-78-4
ATC code N05AG02
PubChem 16362
DrugBank APRD00218
Chemical data
Formula C28H29F2N3O 
Mol. mass 461.56
Pharmacokinetic data
Bioavailability at least 40 to 50%
Metabolism hepatic, by cytochrome P450, isoenzymes 3A, and 1A2; metabolites are inactive
Half life 2 to 3 days (average in one study 55 hours)
Excretion urine, and to a lesser extent in feces
Therapeutic considerations
Pregnancy cat.

Teratogenic data in rats exist : drug should only be used when the benefit clearly exceeds the potential harm to the unborn

Legal status

Rx-only, not a controlled narcotic

Routes oral only
 Yes check.svgY(what is this?)  (verify)

Pimozide (sold as Orap) is an antipsychotic drug. It was discovered at Janssen Pharmaceutica in 1963. It has a high potency compared to chlorpromazine (ratio 50-70:1). On a weight basis it is even more potent than haloperidol. It also has special neurologic indications for Tourette syndrome and resistant tics. The side effects include akathisia, tardive dyskinesia, and, more rarely, neuroleptic malignant syndrome and long QT syndrome.

Contents

Uses

Pimozide logo

Pimozide is used in its oral preparation in schizophrenia and chronic psychosis (on-label indications in Europe only), Tourette syndrome and resistant tics (Europe, USA and Canada). In Germany the 1mg tablet is indicated for the treatment of some forms of reactive depression.

Off-label use

Pimozide has been used in the treatment of delusional disorder.[1]

It has been used for delusions of parasitosis.[2]

Use as a Listeria monocytogenes inhibitor has been described.[3]

Chemistry

Pimozide is a diphenylbutylpiperidine derivative.

Pharmacology

Pharmacokinetics

Plasma levels of pimozide can vary widely between patients, and in insufficient response therapeutic drug monitoring may be required to ascertain that the patient is developing adequate plasma levels before withdrawing the drug and attempting other antipsychotics.

Pharmacodynamics

Pimozide blocks the following postsynaptic receptors according to Bezchlinyk-Butler and Jeffries:

  • Extremely strong: D2
  • Strong: D3, ALPHA1, 5-HT2A
  • Moderate to moderately strong: DE1, D4, ALPHA2
  • Weak: ACH, H1
  • Extremely weak: 5-HT1A


Pimozide also inhibits moderately the dopamine-reuptake from the synaptic cleft, accounting for the stimulant properties of the drug. The inhibition of dopamine-reuptake may also explain the synergistic effects of pimozide in the treatment of ADHD when given together with a stimulant.

Contraindications and precautions

  • Contraindicated in patients taking citalopram (Celexa) and escitalopram (Lexapro) due to prolongation of the QTc interval, as per the FDA.
  • Patients with prominent agitation or anxiety
  • Depressed patients
  • Severe intoxication with alcohol, opiates, and psychoactive drugs (e.g. antidepressants, benzodiazepines)
  • Preexisting Parkinson's disease
  • Comedication with nefazodone, clarithromycin and vetoconazol (see below under interactions)
  • Caution: Anticonvulsive treatment in epileptic patients should not be interrupted. Pimozide may in principle lower the seizure-threshold.
  • Caution: Patients under 18 yrs. of age. Side-effects may be particularly frequent and severe. Treatment should be started with low initial dose and the dose increased very slowly.

Side-effects

Pimozide can have severe, potentially fatal side effects. As with other dopamine antagonists pimozide can cause various extrapyramidal side-effects, including tardive dyskinesia and Rabbit syndrome. The frequency of extrapyramidal side-effects is quite high. Neuroleptic malignant syndrome may also occur.

In particular, pimozide is known for causing the unpleasant extrapyramidal side-effect akathisia (commonly referred to as "restless pacing") in a large percentage of those who take it. This "restlessness" can sometimes be treated with anticholinergic drugs (mainly benztropine), beta blockers or benzodiazepines, particularly clonazepam (Klonopin). Unfortunately, in many cases this side effect can be so intense that even large doses of these drugs are unable to counter it, and often is so extreme that self-destructive behaviour, including attempting suicide, may occur.

Pimozide has no significant sedative properties, but behaves in some patients as a mild stimulant. If the drug is given shortly before bedtime, insomnia may result. Excitement, agitation, irritability, tension, anxiety, and nightmares have all been seen.

The drug can also cause depression in quite a number of patients, severe enough to result in suicide.

Pimozide has few but nonetheless existing anticholinerg side-effects (e.g. dry mouth, obstipation, urinary hesitancy), rarely of clinical importance.

Pimozide may rarely cause seizures of the grand-mal-type. Patients with epilepsia should be counselled to maintain anticonvulsive therapy.

Particularly disturbing is a relatively high incidence of the long QT syndrome, which may lead to ventricular tachycardia, torsades de pointes and death via ventricular fibrillation.

There is also specific information of carcinogenity both in animals and humans. The carcinogenity in animals has been proven and the carcinogenity in man is strongly suspected (breast cancer and probably liver tumors).

Because of these serious side effects, Pimozide should only be used after the patient has received full information about the drug and agrees to treatment with it despite the risks (fully informed consent).

Interactions

  • Central Depressants: Action of the other drug may be increased.
  • Drugs competing for the same cytochrome subenzymes: Risk of mutual and uncontrollable increased action. Nefazodone, Clarithromycin and Vetoconazol all lead to increased pimozide plasma levels and to a higher incidence of (potentially serious) side-effects of pimozide.
  • Grapefruit juice: Elimination of Pimozide is inhibited. Avoid drinking grapefruit juice during treatment with Pimozide.

Dosage

Due to its long halflife pimozide is usually given once a day (preferably in the morning, because pimozide may have a rather stimulating effect).

Recommended dose ranges are as follows:

  • Acute psychotic disorders: usually 2 to 12mg daily starting with low doses, then slowly increasing. More than 20mg daily should be avoided, because the benefit-risk ratio is unclear
  • Chronic psychotic disorders: for maintenance of acute results 6mg daily is the usual dose
  • Tics: 1 to 16 mg daily in slowly increasing doses
  • Reactive Depression: 1 to 2mg daily
  • ADHD: not clearly established, start with very small doses (e.g. 0.5 to 1.0mg) and increase slowly according to the clinical reaction and the side-effects encountered.

Animal toxicity and human overdose

The precise lethal dose in humans is unknown. The oral LD50 is 228 mg/kg in mice, 5120 mg/kg in rats, 188 mg/kg in guinea pigs, and 40 mg/kg in dogs.

Generally human overdoses show exaggerations of the pharmacologic effect of Pimozide. These are : ECG-abnormalities, severe extrapyramidal reactions, hypotension, and comatose state with respiratory depression.

Treatment is largely symptomatic. No specific antidote exists. Induction of emesis, gastric lavage and the repeated application of activated charcoal can all be helpful. Monitor and stabilize, if necessary, the vital functions. Hospitialization and/or admittance to intensive care treatment is in most cases necessary. Due to the long halflife of Pimozide, the symptoms of overdose may last for several days.

References

  1. ^ Munro, A. (1999) Delusional disorder. Cambridge: Cambridge University Press. ISBN 0-521-58180-X
  2. ^ van Vloten WA (March 2003). "Pimozide: use in dermatology". Dermatol. Online J. 9 (2): 3. PMID 12639456. http://dermatology.cdlib.org/92/reviews/pimozide/vanvloten.html. 
  3. ^ Lieberman LA, Higgins DE (February 2009). "A small-molecule screen identifies the antipsychotic drug pimozide as an inhibitor of Listeria monocytogenes infection". Antimicrob. Agents Chemother. 53 (2): 756–64. doi:10.1128/AAC.00607-08. PMID 19015342. PMC 2630664. http://aac.asm.org/cgi/pmidlookup?view=long&pmid=19015342. 

External links


 
 
Learn More
Pimozide tablets
Antiarrhythmic Drugs: Interactions
Antipsychotic Drugs

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Dictionary. The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.  Read more
Dental Dictionary. Mosby's Dental Dictionary. Copyright © 2004 by Elsevier, Inc. All rights reserved.  Read more
Drug Info. Gold Standard. Copyright © 2008 by Gold Standard. All rights reserved.  Read more
Veterinary Dictionary. Saunders Comprehensive Veterinary Dictionary 3rd Edition. Copyright © 2007 by D.C. Blood, V.P. Studdert and C.C. Gay, Elsevier. All rights reserved.  Read more
Wikipedia. This article is licensed under the Creative Commons Attribution/Share-Alike License. It uses material from the Wikipedia article "Pimozide" Read more