Haloperidol

Brand Name: Haldol

Contents:

Description
Pharmacology
Indications and Usage
Contraindications
Warnings
Precautions
Drug Interactions
Adverse Reactions
Overdose
Dosage
Supplied

Description

Haloperidol (Haldol) is an antipsychotic medication used to treat schizophrenia. It is also used to control certain symptoms associated with Tourette's disorder.

Haloperidol is a butyropherone derivative with antipsychotic properties that has been considered particularly effective in the management of hyperactivity, agitation, and mania. Haloperidol is an effective neuroleptic and also possesses antiemetic properties; it has a marked tendency to provoke extrapyramidal effects and has relatively weak alpha-adrenolytic properties. It may also exhibit hypothermic and anorexiant effects and potentiate the action of barbiturates, general anesthetics, and other CNS depressant drugs.

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Pharmacology

HALDOL Decanoate 50 and HALDOL Decanoate 100 are the long-acting forms of HALDOL (haloperidol). The basic effects of haloperidol decanoate are no different from those of HALDOL with the exception of duration of action. Haloperidol blocks the effects of dopamine and increases its turnover rate; however, the precise mechanism of action is unknown.

Peak plasma levels of haloperidol occur within 2 to 6 hours of oral dosing and about 20 minutes after i.m. administration.

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Indications and Usage

HALDOL Decanoate 50 and HALDOL Decanoate 100 are long-acting parenteral antipsychotic drugs intended for use in the management of patients requiring prolonged parenteral antipsychotic therapy (e. g., patients with chronic schizophrenia).

It may also be of value in the management of aggressive and agitated behavior in patients with chronic brain syndrome and mental retardation and in the symptomatic control of Gilles de la Tourette's syndrome.

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Contraindications

Haloperidol is contraindicated in severe toxic central nervous system depression or comatose states from any cause and in individuals who are hypersensitive to this drug or have Parkinson's disease.

Children: Safety and effectiveness in young children have not been established; therefore, haloperidol is contraindicated in this age group.

Pregnancy and Nursing: Do not administer to pregnant or nursing women.

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Warnings

Tardive Dyskinesia: A syndrome consisting of potentially irreversible, involuntary, dyskinetic movements may develop in patients treated with antipsychotic drugs. Although the prevalence of the syndrome appears to be highest among the elderly, especially elderly women, it is impossible to rely upon prevalence estimates to predict, at the inception of antipsychotic treatment, which patients are likely to develop the syndrome. Whether antipsychotic drug products differ in their potential to cause tardive dyskinesia is unknown. Both the risk of developing tardive dyskinesia and the likelihood that it will become irreversible are believed to increase as the duration of treatment and the total cumulative dose of antipsychotic drugs administered to the patient increase. However, the syndrome can develop, although much less commonly, after relatively brief treatment periods at low doses. There is no known treatment for established cases of tardive dyskinesia, although the syndrome may remit, partially or completely, if antipsychotic treatment is withdrawn.

Chronic antipsychotic treatment should generally be reserved for patients who suffer from a chronic illness that 1) is known to respond to antipsychotic drugs, and 2) for whom alternative, equally effective, but potentially less harmful treatments are not available or appropriate.

Neuroleptic Malignant Syndrome (NMS): A potentially fatal symptom complex sometimes referred to as Neuroleptic Malignant Syndrome (NMS) has been reported in association with antipsychotic drugs. Clinical manifestations of NMS are hyperpyrexia, muscle rigidity, altered mental status (including catatonic signs) and evidence of autonomic instability (irregular pulse or blood pressure, tachycardia, diaphoresis, and cardiac dysrhythmias). Additional signs may include elevated creatine phosphokinase, myoglobinuria (rhabdomyolysis) and acute renal failure.

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The management of NMS should include 1) immediate discontinuation of antipsychotic drugs and other drugs not essential to concurrent therapy, 2) intensive symptomatic treatment and medical monitoring, and 3) treatment of any concomitant serious medical problems for which specific treatments are available. There is no general agreement about specific pharmacological treatment regimens for uncomplicated NMS. If a patient requires antipsychotic drug treatment after recovery from NMS, the potential reintroduction of drug therapy should be carefully considered.

Bronchopneumonia: A number of cases of bronchopneumonia, some fatal, have followed the use of antipsychotic drugs, including HALDOL (haloperidol). It has been postulated that lethargy and decreased sensation of thirst due to central inhibition may lead to dehydration, hemoconcentration and reduced pulmonary ventilation. Therefore, if the above signs and symptoms appear, especially in the elderly, the physician should institute remedial therapy promptly. Although not reported with HALDOL, decreased serum cholesterol and/ or cutaneous and ocular changes have been reported in patients receiving chemically-related drugs.

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Precautions

Haldol should be administered cautiously to patients:

• with severe cardiovascular disorders, because of the possibility of transient hypotension and/or precipitation of anginal pain.

• receiving anticonvulsant medications, with a history of seizures, or with EEG abnormalities, because Haloperidol may lower the convulsive threshold. If indicated, adequate anticonvulsant therapy should be concomitantly maintained. - with known allergies, or with a history of allergic reactions to drugs.

• receiving anticoagulants, since an isolated instance of interference occurred with the effects of one anticoagulant (phenindione).

Taking Haloperidol may cause increased sensitivity to the sun. Avoid exposure to the sun or sunlamps until you know how you react to this medicine. Use a sunscreen or protective clothing if you must be outside for a prolonged period. Do not become overheated in hot weather, during exercise or other activities since heat stroke may occur while you are taking this medicine.

Usage in Children:: The safety and effectiveness of haloperidol in children below the age of 18 have not been established.

Pregnancy & Nursing: There are no adequate and well-controlled studies in pregnant women. There are reports, however, of cases of limb malformations observed following maternal use of Haloperidal along with other drugs which have suspected teratogenic potential during the first trimester of pregnancy. Causal relationships were not established with these cases. Since such experience does not exclude the possibility of fetal damage due to Haldol, haloperidol decanoate should be used during pregnancy or in women likely to become pregnant only if the benefit clearly justifies a potential risk to the fetus.

Since haloperidol is excreted in human breast milk, infants should not be nursed during drug treatment with haloperidol decanoate.

Interference with Cognitive or Motor Performance: Haloperidol decanoate may impair the mental and/or physical abilities required for the performance of hazardous tasks such as operating machinery or driving a motor vehicle. The ambulatory patient should be warned accordingly. The use of alcohol with this drug should be avoided due to possible additive effects and hypotension.

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Drug Interactions

An encephalopathic syndrome (characterized by weakness, lethargy, fever, tremulousness and confusion, extrapyramidal symptoms, leukocytosis, elevated serum enzymes, BUN, and FBS) followed by irreversible brain damage has occurred in a few patients treated with lithium plus Haloperidol. A causal relationship between these events and the concomitant administration of lithium and Haloperidol has not been established; however, patients receiving such combined therapy should be monitored closely for early evidence of neurological toxicity and treatment discontinued promptly if such signs appear. As with other antipsychotic agents, it should be noted that Haloperidol may be capable of potentiating CNS depressants such as anesthetics, opiates, and alcohol.

Haloperidol may antagonize the action of epinephrine and other sympathomimetic agents and reverse the blood pressure-lowering effects of adrenergic-blocking agents, such as guanethidine.

BEFORE USING THIS MEDICINE: INFORM YOUR DOCTOR OR PHARMACIST of all prescription and over-the-counter medicine that you are taking. This especially includes blood pressure medicine and CNS depressants; epinephrine; levodopa; lithium; other medicines for nervous, mental, and emotional conditions; metoclopramide; metyrosine; promethazine; rauwolfia alkaloids; or trimeprazine. Inform your doctor of any other medical conditions, allergies, pregnancy, or breast-feeding.

When haloperidol is used to control mania in cyclic disorders, there may be a rapid mood swing to depression.

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Adverse Reactions

CNS Effects: Extrapyramidal Symptoms (EPS) - EPS during the administration of haldol (haloperidol) have been reported frequently, often during the first few days of treatment. EPS can be categorized generally as Parkinson-like symptoms, akathisia, or dystonia (including opisthotonos and oculogyric crisis). While all can occur at relatively low doses, they occur more frequently and with greater severity at higher doses. The symptoms may be controlled with dose reductions or administration of antiparkinson drugs such as benztropine mesylate USP or trihexyphenidyl hydrochloride USP. It should be noted that persistent EPS have been reported; the drug may have to be discontinued in such cases.

Tardive Dyskinesia: As with all antipsychotic agents HALOPERIDOL has been associated with persistent dyskinesias. Tardive dyskinesia, a syndrome consisting of potentially irreversible, involuntary, dyskinetic movements, may appear in some patients on long-term therapy with haloperidol decanoate or may occur after drug therapy has been discontinued. The risk appears to be greater in elderly patients on high-dose therapy, especially females. The symptoms are persistent and in some patients appear irreversible. The syndrome is characterized by rhythmical involuntary movements of tongue, face, mouth or jaw (e. g., protrusion of tongue, puffing of cheeks, puckering of mouth, chewing movements). Sometimes these may be accompanied by involuntary movements of extremities and the trunk. There is no known effective treatment for tardive dyskinesia; antiparkinson agents usually do not alleviate the symptoms of this syndrome. It is suggested that all antipsychotic agents be discontinued if these symptoms appear.

Tardive Dystonia: Tardive dystonia, not associated with the above syndrome, has also been reported. Tardive dystonia is characterized by delayed onset of choreic or dystonic movements, is often persistent, and has the potential of becoming irreversible.

Other CNS Effects: Insomnia, restlessness, anxiety, euphoria, agitation, drowsiness, depression, lethargy, headache, confusion, vertigo, grand mal seizures, exacerbation of psychotic symptoms including hallucinations, and catatonic-like behavioral states which may be responsive to drug withdrawal and/ or treatment with anticholinergic drugs.

Side effects, that may go away during treatment, include mild drowsiness, dizziness, changes in menstrual cycle, or swelling or pain in breasts. If they continue or are bothersome, check with your doctor. CHECK WITH YOUR DOCTOR AS SOON AS POSSIBLE if you experience severe drowsiness or sleepiness, drooling, difficulty speaking or swallowing, muscle stiffness, fever, restless body movements, mild hand or leg tremors, or other unusual body movements or muscle twitching. If you notice other effects not listed above, contact your doctor, nurse, or pharmacist.

Drug Abuse and Dependence

Withdrawal Emergent Neurological Signs: Generally, patients receiving short-term therapy experience no problems with abrupt discontinuation of antipsychotic drugs. However, some patients on maintenance treatment experience transient dyskinetic signs after abrupt withdrawal. In certain of these cases the dyskinetic movements are indistinguishable from the syndrome described below under "Tardive Dyskinesia" except for duration. Although the long-acting properties of haloperidol decanoate provide gradual withdrawal, it is not known whether gradual withdrawal of antipsychotic drugs will reduce the rate of occurrence of withdrawal emergent neurological signs.

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Overdose

Signs and Symptoms

Symptoms of Haloperidol / Haldol overdose may include agitation, very dry mouth, unusual drowsiness or deep sleep, slow or shallow breathing, rapid or irregular pulse, and muscle weakness, rigidity, or tremor.

Treatment

If you or someone you know may have used more than the recommended dose of this medicine, contact your local poison control center or emergency room immediately.

Since there is no specific antidote, treatment is primarily supportive. A patent airway must be established by use of an oropharyngeal airway or endotracheal tube or, in prolonged cases of coma, by tracheostomy. Respiratory depression may be counteracted by artificial respiration and mechanical respirators. Hypotension and circulatory collapse may be counteracted by use of intravenous fluids, plasma, or concentrated albumin, and vasopressor agents such as metaraminol, phenylephrine and norepinephrine. In case of severe extrapyramidal reactions, antiparkinson medication should be administered, and should be continued for several weeks, and then withdrawn gradually as extrapyramidal symptoms may emerge. ECG and vital signs should be monitored.

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Dosage

Sometimes haloperidol must be taken for several days to several weeks before its full effect is reached.

Do not exceed the recommended dosage or take this medicine for longer than prescribed. Exceeding the recommended dose or taking this medicine for longer than prescribed may be habit forming.

• Follow the directions for using this medicine provided by your doctor.
• Store this medicine at room temperature, in a tightly-closed container, away from heat and light.
• Take this medicine everyday at evenly spaced intervals.
• If you miss a dose of this medicine, take it as soon as possible. Take the remaining doses for the day at evenly spaced intervals. Do not take 2 doses at once.
• This medicine may be taken with food if it upsets your stomach.

Additional Information:: Do not share this medicine with others for whom it was not prescribed. Do not use this medicine for other health conditions. Keep this medicine out of the reach of children.

Adults: 1 to 2 mg 2 or 3 times daily, initially, followed by upward adjustment as tolerated until the desired effect is achieved or limiting side effects appear. Clinical experience has shown that it is seldom necessary to employ dosages greater than 4 to 6 mg 3 times daily. However, 30 to 40 mg daily may be required in severely disturbed patients who remain inadequately controlled by lower doses. Up to 100 mg daily has been used occasionally in particularly resistant patients. Nevertheless, the safety of prolonged administration of the higher doses has not been established. After a therapeutic response has been achieved, dosages should be gradually adjusted downwards until a schedule providing adequate maintenance is reached.

Maintenance dosages are commonly in the range of 1 to 2 mg 3 or 4 times daily.

Children, Elderly & Debilitated Patients: Lower doses are recommended in these patients since they may be more sensitive to the drug.

Initial daily doses ranging from 0.5 to 1.5 mg (0.25 to 0.5 mg, 2 or 3 times a day) should be employed. Upward adjustment of these doses should be made gradually; maximum and maintenance doses should be individualized and are generally lower in this type of patient.

Discontinuation: After you stop taking this medicine, your body may need time to adjust. Check with your doctor if you experience trembling of fingers and hands, or uncontrolled movements of mouth, tongue, and jaw.

IF USING THIS MEDICINE FOR AN EXTENDED PERIOD OF TIME, obtain refills before your supply runs out.

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How Supplied

Haloperidol comes in an injectable solution.

Tablets: 1 mg, 2 mg, 5 mg, 20 mg.

The information in this monograph is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects. This information is generalized and is not intended as specific medical advice. If you have questions about the medicines you are taking or would like more information, check with your doctor, pharmacist, or nurse. Last updated 3/03.

Copyright © 2003 Healthyplace Inc. All rights reserved.

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