A typical antipsychotic medication.
Used in the treatment of schizophrenia, tics in Tourette syndrome, mania in bipolar disorder, nausea and vomiting, delirium, agitation, acute psychosis, and hallucinations in alcohol withdrawal.
Trade name Haldol.
Administered by mouth, as an injection into a muscle, or intravenously.
Haloperidol typically works within thirty to sixty minutes.
A long-acting formulation available as an injection every four weeks in people with schizophrenia or related illnesses, who either forget or refuse to take the medication by mouth.
It is the most commonly used typical antipsychotic.
Pregnancy US: C (Risk not ruled out)
Bioavailability 60–70% (Oral)
Protein binding 90%
Metabolism Liver-mediated
Elimination half-life 14–26 hours (IV), 20.7 hours (IM), 14–37 hours (oral)
Excretion by bile into feces and in urine
May result in a movement disorder known as tardive dyskinesia which may be permanent, neuroleptic malignant syndrome and QT interval prolongation.
In older people with dementia it results in an increased risk of death.
It should not be used in Parkinson’s disease.
In ICU delirium treated with haloperidol did not lead to a significantly greater number of days alive and out of the hospital at 90 days than placebo.
Used in the control of:
Acute psychosis, such as drug-induced psychosis and psychosis associated with high fever or metabolic disease.
Adjunctive treatment of alcohol and opioid withdrawal.
Agitation and confusion associated with cerebral sclerosis.
Alcohol-induced psychosis.
Hallucinations in alcohol withdrawal.
Hyperactive delirium
Hyperactivity, aggression
Otherwise uncontrollable, severe behavioral disorders in children and adolescents
Schizophrenia
Therapeutic trial in personality disorders, such as borderline personality disorder
Treatment of intractable hiccups
Treatment of neurological disorders, such as tic disorders such as Tourette syndrome, and chorea
Treatment of severe nausea and emesis in postoperative and palliative care, and for palliating adverse effects of radiation therapy and chemotherapy.
Haloperidol was considered indispensable for treating psychiatric emergency situations, although the newer atypical drugs have gained a greater role.
In a comparison of 15 antipsychotics in schizophrenia, it demonstrated standard effectiveness, but because of troublesome adverse effects alternative antipsychotic agents with less likelihood of adverse effects such as parkinsonism, akathisia and acute dystonias are more desirable.
It substantially increases the risk of movement disorders.
Should be given during pregnancy only if the benefit to the mother clearly outweighs the potential fetal risk.
It is found in significant amounts in breast milk, and breastfed children sometimes show extrapyramidal symptoms.
Doses of haloperidol greater than 5 mg increased the risk of side effects without improving efficacy.
Depot forms are also available
Adverse effects:
produce significant extrapyramidal side effects-in a meta-analysis of the comparative efficacy and tolerability of 15 antipsychotic drugs it was the most prone of the 15 for causing extrapyramidal side effects.
With more than 6 months of use 14% percent of users gain weight..
Common side effects:
Extrapyramidal side effects including:
Akathisia
Dystonia
Muscle rigidity
Parkinsonism
Hypotension
Anticholinergic side effects:
Blurred vision
Constipation
Dry mouth
Somnolence
Contraindications to use include: Pre-existing coma,
Acute stroke
Severe intoxication with alcohol or other central depressant drugs
Known allergy.
Known heart disease
When given to people with Alzheimer’s with mild behavioural problems it may make the condition worse.
Elderly patients with dementia-related psychosis have 1.6 to 1.7 times higher risk of death than that of placebo-treated patients.
IV administration association with risk of hypotension or orthostatic collapse.
Patients at risk for the development of QT prolongation with hypokalemia, and concomitant use of other drugs causing QT prolongation.
With a history of leukopenia a complete blood count should be monitored frequently during the first few months of therapy.
With other central depressants actions and side effects of these drugs such as sedation, or respiratory depression are increased.
The doses of concomitantly used opioids can be reduced by 50%.
Drugs metabolized by the CYP3A4 enzyme system: inducers such as carbamazepine, phenobarbital, and rifampicin decrease plasma levels and inhibitors such as quinidine, buspirone, and fluoxetine increase plasma levels.
The metabolism and elimination of tricyclics are significantly decreased, increasing toxicity with anticholinergic and cardiovascular side effects, and lowering of seizure threshold.
Overdose symptoms:
Anticholinergic side effects of dry mouth, constipation, paralytic ileus, difficulties in urinating, decreased perspiration.
Coma in severe cases.
Respiratory depression
Hypotension
Hypertension
Rarely, serious ventricular arrhythmia with or without prolonged QT-time.
Sedation.
Severe extrapyramidal side effects with muscle rigidity and tremors, akathisia.
Treatment of overdose is symptomatic and involves intensive care with stabilization of vital functions.
With early detection of oral overdose, induction of emesis, gastric lavage, and the use of activated charcoal can all be tried.
Antidotes such as bromocriptine or ropinirole may be used to treat the extrapyramidal effects caused by haloperidol.
QT prolongation and severe arrhythmias should be treated with antiarrhythmic measures.
Haloperidol, 10-mg oral tablet.
The bioavailability of oral haloperidol ranges from 60–70%.
The drug is well and rapidly absorbed with a high bioavailability when injected intramuscularly.
The plasma concentrations of haloperidol decanoate reaches a peak at about six days after the injection, falling thereafter, with an approximate half-life of three weeks.
With intravenous injections the bioavailability is 100% and onset of action is seen within seconds.
The half-life is 14.1 to 26.2 hours.
The duration of action is four to six hours.
Plasma levels of four to 25 micrograms per liter are required for therapeutic action, and determination of plasma levels can be used to calculate dose to check compliance.
Its concentration in brain tissue is about 20-fold higher compared to blood levels.
It is only slowly eliminated from brain tissue, explaining the slow disappearance of side effects when the medication is stopped.
It is heavily protein bound in human plasma, with a free fraction of only 7.5 to 11.6%.
Metabolism is by the liver with only about 1% of the drug excreted unchanged in the urine.
Hepatic clearance is primarily by glucuronidation, followed by reduction and CYP-mediated oxidation, primarily by CYP3A4.