Directions for use and doses
IM, in the gluteal region.
Intended exclusively for adults, exclusively for intramuscular administration. Do not administer i.v.
Doses exceeding 3 ml should be avoided to avoid an unpleasant feeling of fullness at the injection site.
Adults: Patients on long-term treatment with oral antipsychotics (mainly haloperidol) may be advised to switch to depot injections. The dose should be adjusted on an individual basis due to significant individual differences in response. Dose selection should be carried out under strict medical supervision of the patient. The choice of the initial dose is carried out taking into account the symptoms of the disease, its severity, the dose of haloperidol or other antipsychotics prescribed during previous treatment.
At the beginning of treatment, it is recommended to prescribe doses 10-15 times higher than the dose of oral haloperidol every 4 weeks, which usually corresponds to 25-75 mg of haloperidol decanoate (0.5-1.5 ml). The maximum initial dose should not exceed 100 mg.
Depending on the effect, the dose can be increased stepwise by 50 mg until the optimal effect is obtained. Typically the maintenance dose corresponds to 20 times the daily dose of oral haloperidol. If symptoms of the underlying disease return during dose titration, treatment with haloperidol decanoate can be supplemented with oral haloperidol. Typically, injections are given every 4 weeks, but due to large individual differences in effectiveness, more frequent use of the drug may be required.
Elderly patients and patients with oligophrenia: a lower initial dose is recommended, for example, 12.5–25 mg every 4 weeks. In the future, depending on the effect, the dose may be increased.
Description of the drug HALOPERIDOL DECANOATE
When used simultaneously with drugs that have a depressant effect on the central nervous system, ethanol may increase central nervous system depression, respiratory depression and hypotensive effects.
With the simultaneous use of drugs that cause extrapyramidal reactions, the frequency and severity of extrapyramidal effects may increase.
With the simultaneous use of drugs with anticholinergic activity, the anticholinergic effects may be enhanced.
When used simultaneously with anticonvulsants, it is possible to change the type and/or frequency of epileptiform seizures, as well as reduce the concentration of haloperidol in the blood plasma; with tricyclic antidepressants (including desipramine) - the metabolism of tricyclic antidepressants decreases and the risk of developing seizures increases.
With simultaneous use, haloperidol potentiates the effect of antihypertensive drugs.
When used simultaneously with beta-blockers (including propranolol), severe arterial hypotension is possible. With the simultaneous use of haloperidol and propranolol, a case of severe arterial hypotension and cardiac arrest has been described.
With simultaneous use, a decrease in the effect of indirect anticoagulants is observed.
When used simultaneously with lithium salts, the development of more pronounced extrapyramidal symptoms is possible due to increased blockade of dopamine receptors, and when used in high doses, irreversible intoxication and severe encephalopathy are possible.
When used simultaneously with venlafaxine, it is possible to increase the concentration of haloperidol in the blood plasma; with guanethidine - the hypotensive effect of guanethidine may be reduced; with isoniazid - there are reports of increased concentrations of isoniazid in the blood plasma; with imipenem - there are reports of transient arterial hypertension.
When used simultaneously with indomethacin, drowsiness and confusion are possible.
When used simultaneously with carbamazepine, which is an inducer of microsomal liver enzymes, it is possible to increase the rate of metabolism of haloperidol. Haloperidol may increase plasma concentrations of carbamazepine. Symptoms of neurotoxicity may occur.
With simultaneous use, the therapeutic effect of levodopa and pergolide may be reduced due to blockade of dopamine receptors by haloperidol.
When used simultaneously with methyldopa, sedation, depression, dementia, confusion, and dizziness are possible; with morphine - myoclonus may develop; with rifampicin, phenytoin, phenobarbital - a decrease in the concentration of haloperidol in the blood plasma is possible.
When used concomitantly with fluvoxamine, there are limited reports of a possible increase in the concentration of haloperidol in the blood plasma, which is accompanied by toxic effects.
When used simultaneously with fluoxetine, the development of extrapyramidal symptoms and dystonia is possible; with quinidine - an increase in the concentration of haloperidol in the blood plasma; with cisapride - prolongation of the QT interval on the ECG.
When used simultaneously with epinephrine, it is possible to “pervert” the pressor effect of epinephrine, and as a result, the development of severe arterial hypotension and tachycardia.
Why is Haloperidol prescribed?
Indications for the use of Haloperidol
Haloperidol is one of the most commonly used antipsychotics in the world. It is known that the antipsychotic Haloperidol is often prescribed for many mental disorders. So this drug is recommended for schizophrenia (hallucinations and delusions), Tourette syndrome (to combat tics and vocalisms), hyperactivity (which can manifest itself in the form of impulsivity, poor concentration, severe aggression, mood instability, serious behavioral disorders, including in children , such as aggressive, explosive hyperexcitability and even to suppress drug-resistant hiccups). We can say that Haloperidol is the “king of neuroleptics,” and by and large, in particular, in terms of the power of its effect and all psychotropic drugs.
Haloperidol as a broad-spectrum drug
Haloperidol is a first-generation drug (a typical antipsychotic) that exerts its antipsychotic effects by blocking dopamine D2 receptors in the brain. When 72% of dopamine receptors are blocked, this drug reaches its maximum effect. Haloperidol is not selective for the D2 receptor. It also has noradrenergic, cholinergic and histaminergic blocking effects. Blocking these receptors is associated with various side effects.
Haloperidol dosage forms
Haloperidol comes in various forms; the oral route is the most common. For oral use, it is available in the form of tablets and oral concentrate. It is also available in nasal spray form. Haloperidol lactate is used as a short-acting parenteral solution, available for intramuscular and intravenous administration. Haloperidol decanoate is available as a long-acting intramuscular formulation.
Pharmacokinetics of Haloperidol
The pharmacokinetics of Haldol varies depending on patient characteristics such as gender, age, weight, and race. The half-life of Haldol is usually 14.5-36.7 hours. The half-life for chronic use is 21 days. The average clearance time for Haldol is approximately 24.2 ml/min. Haloperidol is metabolized in the liver by oxidative N-dealkylation to the metabolites piperidine and 4-fluorobenzoylpropionic acid. It is important for a physician to understand the elimination rate of Haldol because it explains the long-term effects of the drug and the average timeline for tracking side effects.
Haloperidol for psychosis
Haloperidol for psychosis can be used both orally and intramuscularly. For moderate symptoms: 0.5-2 mg 2-3 times a day orally. In some resistant cases, a larger dose may be required. To quickly relieve acute agitation, an intramuscular injection can be administered in a dose of 2 to 5 mg every 8 hours.
Haloperidol for Tourette's syndrome
Haloperidol for Tourette's syndrome is used in a dose of 0.5-2 mg orally 2-3 times a day in cases with moderate severity of symptoms, and in severe cases of this neuropsychiatric disorder it can be higher: from 3 to 5 mg 2-3 times a day day. However, by and large, the safety and consequences of using Haloperidol in children have not been studied.
Can I take Haloperidol during pregnancy?
During pregnancy: There have been no well-controlled studies of the use of Haloperidol in pregnant women. However, there are several case reports of limb malformations in a newborn whose mother took Haloperidol, but the cause-and-effect relationship in these cases has not been properly established. Because these experiences do not rule out the possibility of fetal abnormalities due to Haloperidol, this drug should only be used if the benefit outweighs the potential risk to the fetus.
Side effects of Haloperidol
Haloperidol causes a wide range of neurological side effects, especially in old age; for example, the prevalence of tardive dyskinesia is highest among older patients, especially older women. The main neurological side effects when taking Haloperidol are considered to be extrapyramidal disorders.
Extrapyramidal symptoms
Extrapyramidal symptoms that occur while taking haloperidol include: dystonia (develops within several hours or days after the onset of the disease, can manifest itself in the form of muscle spasm, stiffness, oculogyric crisis, torticollis), akathisia (develops within several days or months after taking Haloperidol, characterized by anxiety and severe motor agitation), neuroleptic malignant syndrome (infrequent but serious condition, can be manifested by high fever, muscle stiffness), parkinsonism (develops after several days or months of taking haloperidol) and tardive dyskinesia (develops over the years, is extremely painful and difficult to treat for patients, the syndrome is clearly manifested, especially in the orofacial area).
Common side effects of Haloperidol
The general side effects of Haloperidol are not as frightening to patients as extrapyramidal symptoms, however, they are also painful and no less, and may even be more dangerous for the patient. Common side effects of Haloperidol include: anticholinergic effects (fever, dry mouth, drowsiness or sedation, constipation, urinary retention), weight gain, increased prolactin (mastopathy, oligomenorrhea or amenorrhea, erectile dysfunction, etc.).
Other side effects of Haloperidol
A number of side effects of Haloperidol are somewhat less common than those described above. These side effects include: orthostatic hypotension (after intramuscular administration of Haloperidol), tachycardia, palpitations. While taking Haloperidol, the following were recorded: agitation, generalized anxiety, cerebral edema, new-onset depression, dizziness, euphoric mood, headache, insomnia, poikilothermia, anxiety, general weakness, confusion, anorexia, constipation, dyspepsia, intestinal obstruction, decreased emetic reflex, blurred vision (with prolonged use).
Unusual Side Effects of Haloperidol
ECG changes (QT prolongation, torsades de pointes), photosensitivity reactions, generalized itching, diarrhea, gastrointestinal disorders, blood dyscrasias, problems with ejaculation are often considered atypical side effects of treatment with Haloperidol.
Rare side effects of Haloperidol
Rare side effects of Haloperidol include seizures, cholestatic jaundice and priapism.
Contraindications to the use of Haloperidol
Haloperidol is contraindicated in patients with documented hypersensitivity to this drug, in Parkinson's disease, dementia with Lewy bodies, in a comatose patient, or in any condition of central nervous system (CNS) depression. Since many drugs (barbiturates, benzodiazepines and opioids) can cause CNS depression, concomitant use of Haloperidol should be avoided or used with great caution. A fairly common mistake made by psychiatrists in our country is the joint prescription of Haloperidol with Phenazepam, a benzodiazepine drug.
Monitoring the safety of treatment with Haloperidol
Due to the possible development of side effects, patients receiving Haloperidol need to be monitored, especially when taking the intramuscular form. It is easy to monitor by taking a test for the concentration of Haloperidol in the blood. Haloperidol blood concentrations should fall within the therapeutic range of 2 to 15 ng/ml in serum. Blood levels should be monitored at 12- or 24-hour intervals or after the patient's last dose of Haloperidol.
Toxicity of Haloperidol
The most notable toxic effects of haloperidol are: 1) severe extrapyramidal symptoms, hypotension, sedation. The patient may fall into a coma with severe respiratory depression or shock from hypotension. Extrapyramidal symptoms include muscle weakness or rigidity and generalized or localized tremors, which may be characterized by akinetic or agitated movements, respectively. Haloperidol overdose is also associated with ECG changes known as pointe changes, which can cause arrhythmia or even cardiac arrest.
Since there is no specific antidote, maintenance therapy is the mainstay of Haloperidol toxicity. If a patient develops signs of toxicity, the physician should consider gastric lavage or induction of vomiting followed by activated charcoal as soon as possible. Maintaining a patent airway, breathing, and circulation are critical factors for survival. The airway should be maintained through the use of an oropharyngeal airway or endotracheal tube or tracheostomy if the patient is comatose. Respiratory depression can be managed with artificial respiration or mechanical respirators in severe cases. Hypotension and circulatory collapse can be treated with intravenous fluids, concentrated albumin, and vasopressors (Phenylephrine or Norepinephrine). Epinephrine should not be used as it may lower blood pressure. If a patient develops severe extrapyramidal reactions, antiparkinsonian medications should be considered. ECG and vital signs require regular monitoring. Cardiac monitoring should be continued until the ECG becomes normal, especially if there is evidence of torsades de pointes, QT prolongation, or arrhythmia. If a patient develops arrhythmias that may be life-threatening, treatment with appropriate antiarrhythmic drugs should be started immediately.
Haloperidol withdrawal syndrome
In addition to the usual side effects of typical antipsychotics, Haldol (Haloperidol) presents with neurological withdrawal symptoms upon discontinuation of the drug, presenting as dyskinetic movements that vary in duration compared to tardive dyskinesia.
