Haloperidol
Haloperidol is a generic medication for the drug :
Haloperidol medication comes in several different strengths; click on the strength you need to view prices from pharmacies competing to earn your business.
|
Haloperidol 0.500 mg
|
Haloperidol 1 mg
|
Haloperidol 2 mg
|
|
Haloperidol 5 mg
|
Haloperidol 10 mg
|
Haloperidol LA inj. 50 mg/mL
|
|
Haloperidol LA inj. 100mg/ml
|
Pharmacology
Pharmacokinetics
Haloperidol is well absorbed after oral administration. Peak plasma concentrations are achieved within 2 to 6 hours. Its elimination half-life is approximately 20 hours. Following im injection, peak concentrations occur within 10 to 20 minutes, with full pharmacologic effect in 30 to 45 minutes. Intramuscular injection of haloperidol decanoate is followed by gradual release of the drug from fatty tissues, prolonging its duration of action. Peak concentrations are reached in approximately one week. The apparent half-life of the decanoate injection is 3 weeks.
Haloperidol is approximately 92% bound to albumin and is metabolized mainly in the liver. It is a substrate and inhibitor of CYP3A4 and a substrate of CYP2D6. Haloperidol and its metabolites are excreted slowly in the urine and feces.
Indications
Haloperidol is indicated for:
-
Management of psychotic disorders (e.g., schizophrenia)
-
Management of Tourette's disorder
-
Management of manic states
Haloperidol is also used in the management of acute agitation and delirium. It has also been used as an antiemetic, in the treatment of intractable hiccoughs and in the management of severe agitation in patients with acute alcohol withdrawal, although this use is not evidence-based and sedative-hypnotics such as benzodiazepines are preferred.
Precautions
Drug Interactions
Additive sedative effects may occur if haloperidol is used concurrently with other CNS depressants such as alcohol, benzodiazepines or opioids.
Concomitant therapy with inducers of CYP3A4 (such as phenytoin or rifampin) may increase the clearance and decrease the effect of haloperidol.
Inhibitors of CYP2D6 or CYP3A4 (e.g., erythromycin, fluoxetine, fluvoxamine, itraconazole, ketoconazole, paroxetine, quinidine) may decrease the clearance of haloperidol and potentiate its pharmacologic and adverse effects.
Some patients have experienced neurotoxicity (e.g., delirium, seizures) during concomitant therapy with haloperidol and lithium, especially when higher than usual doses were used. Patients should be monitored for signs of neurotoxicity if the two drugs are used concurrently.
Haloperidol may antagonize the effects of dopamine agonists such as levodopa.
Occupational Hazards
See Warnings.
Lactation
Haloperidol is excreted in breast milk, with a milk to plasma concentration ratio of approximately 0.65. Cases of decline in mental and psychomotor development at 12-18 mos have been reported in babies whose mothers took 20-40 mg/day while breast-feeding. Caution is recommended when haloperidol is used in breast-feeding mothers; use the lowest effective dose, monitor infant's developmental progress and watch for adverse effects such as drowsiness or lethargy. It may be advisable not to breast-feed when taking high doses.
Children
Safety and efficacy have not been established for children under 3 years of age.
Food Interactions
Oral liquid formulations should not be mixed with coffee or tea as a precipitate may form.
Pregnancy
There have been some reports of limb defects in infants exposed to haloperidol in the first trimester. Infants exposed at any point during gestation should be observed for possible extrapyramidal effects. The decision to use haloperidol during pregnancy should be based on whether the expected benefit of therapy justifies the potential risk to the exposed fetus.
Contraindications
Haloperidol is contraindicated in patients with hypersensitivity to haloperidol or any component of the formulation, and in patients with severe CNS depression, Parkinson's disease or coma.
Warnings
Tardive Dyskinesia: The use of haloperidol has been associated with the chronic, potentially irreversible movement disorder, tardive dyskinesia. Duration of use, daily dose and possibly total cumulative dose are important risk factors for the development of tardive dyskinesia, although it has occurred following as little as 6 months of continuous therapy. Other risk factors include age, history of acute extrapyramidal side effects, poor antipsychotic response to the drug and female gender. There is no standard treatment for tardive dyskinesia, although discontinuing the antipsychotic, when possible, may lead to remission of symptoms. Fine vermicular movements of the tongue may be an early sign of tardive dyskinesia. Discontinuing the drug when this occurs may prevent full onset of the syndrome.
Neuroleptic Malignant Syndrome: This potentially fatal syndrome characterized by muscle rigidity, fever/hyperthermia, labile blood pressure and fluctuating levels of consciousness, can occur in patients taking haloperidol and other antipsychotics. Dehydration is an additional risk factor. Patients need to be aware of the importance of adequate hydration, particularly in situations involving environmental exposure to extreme heat.
Sedation: Although haloperidol is less sedating than many first-generation antipsychotics, patients should be warned of potential sedative effects that could impair their ability to perform tasks requiring mental alertness.
Adverse Effects
Endocrine
Haloperidol can cause hyperprolactinemia, leading to symptoms such as breast engorgement and lactation, sexual dysfunction, mastalgia or gynecomastia in some patients. Hypoglycemia is a rare side effect.
Hematologic
Mild and transient leukopenia can occur with haloperidol and other antipsychotics. Agranulocytosis is a rare side effect of antipsychotics. If patients taking haloperidol present with sore throat, leukoplakia, erythema, ulcerations of the pharynx, usually within the first 8 weeks of therapy, a white blood cell count should be obtained.
Ophthalmologic
Although haloperidol has a mild anticholinergic effect, the possibility of increased intraocular pressure should be considered when haloperidol is used with other drugs with anticholinergic properties.
CNS
(See also Warnings, Neuroleptic Malignant Syndrome): Haloperidol, like other high-potency first-generation antipsychotics, has a relatively high propensity to cause extrapyramidal side effects such as dystonias (briefly sustained or fixed abnormal movements), akathisia (restlessness) or parkinsonism (e.g., tremor, muscle rigidity, slow movement, blunted or flat affect).
Although haloperidol has a lower propensity than many other antipsychotics to cause anticholinergic side effects such as dry mouth, constipation and urinary retention, these symptoms can emerge when haloperidol is used concurrently with other drugs that have anticholinergic activity.
Haloperidol may lower the seizure threshold, although this occurs more commonly with low-potency antipsychotics.
Cardiovascular
Many antipsychotics, including haloperidol, can cause prolongation of the QTc interval which is associated with the potentially lethal arrhythmia, torsades de pointes. Recurrent syncope, ventricular fibrillation and sudden cardiac death can occur with torsades de pointes. Risk factors for drug-induced QTc prolongation include interaction with other drugs that can prolong the QTc, diabetes, obesity, hypokalemia and congenital long QT syndrome.
Overdose
Symptoms
Symptoms of haloperidol overdose can include extrapyramidal symptoms such as akathisia, dystonic reactions or parkinsonian effects, seizures, hypotension, hypokalemia, altered temperature regulation, arrhythmias, respiratory depression and coma. Neuroleptic malignant syndrome can occur at therapeutic or toxic doses (see Warnings).
Treatment
Do not induce vomiting as the gag reflex may be impaired. Management includes administration of activated charcoal and supportive measures such as maintaining ventilation and monitoring vital signs and renal function. Acute extrapyramidal reactions may respond to the iv administration of an anticholinergic agent such as benztropine or diphenhydramine. Lorazepam, propranolol or an anticholinergic agent may be useful for akathisia. Seizures may be treated with a benzodiazepine such as diazepam. Hypotension can be managed with vasopressors such as norepinephrine, if unresponsive to iv fluids and positioning. Ventricular arrhythmias may respond to sodium bicarbonate and/or lidocaine. If torsades de pointes is present, magnesium or a pacemaker may be effective. Neuroleptic malignant syndrome is usually managed with cooling blankets, cool mist and/or fans for hyperthermia, benzodiazepines and/or dantrolene for muscle rigidity, and hydration.
Hemodialysis, peritoneal dialysis and forced diuresis are not effective in enhancing elimination of haloperidol.
Dosage
Oral: Adults: Psychosis or Tourette's disorder: Initial daily dose is 1.5 to 3 mg, increasing gradually to a usual maintenance dose of 4 to 12 mg daily, in 1 to 2 divided doses. The usual maximum daily dose is 20 mg. In elderly patients, a starting dose of 0.5 to 1 mg daily is recommended.
For behavioral symptoms in elderly patients with dementia, an initial dose of 0.25 to 0.5 mg once or twice daily has been suggested.
Children: 3-12 years (15-40 kg): Initial dose is 0.25 to 0.5 mg/day in 2 to 3 divided doses, increasing by 0.25 to 0.5 mg daily, at intervals of 5 to 7 days, to a maximum of 0.15 mg/kg/day. Usual maintenance dose for psychotic disorders is 0.05 to 0.15 mg/kg/day in 2 to 3 divided doses; for Tourette's disorder, 0.05 to 0.075 mg/kg/day in 2 to 3 divided doses.
Oral haloperidol should be administered with food or milk to avoid GI irritation; the oral concentrate can be mixed with water or an acidic beverage such as juice but should not be mixed with tea or coffee.
IM: Adults: For acute psychosis with agitation/aggression, haloperidol can be administered im at a dose of 2 to 5 mg, in combination with lorazepam. The two drugs can be administered in the same syringe and given as often as every hour, until the patient responds. The usual daily maximum dose of 20 mg applies. For elderly patients, begin with 0.5 to 1 mg haloperidol per dose; it is rarely necessary to go beyond a total of 5 mg.
Long-acting haloperidol decanoate injection is usually administered every 4 weeks in the management of chronic psychotic disorders. The initial dose is approximately 10 to 15 times the previous daily oral dose, with subsequent titration to determine the lowest effective and tolerated dose. The usual range is 50 to 200 mg every 4 weeks. Short-acting preparations may be required for supplementation while dosage titration is taking place.
IV: Adults: Haloperidol has been administered iv in patients with delirium, at a dose of 1 to 2 mg every 2 to 4 hours. In elderly patients a lower dose of 0.25 to 0.5 mg is suggested. Haloperidol decanoate is not to be administered iv.
