Haloperidol (Dosage)
Haloperidol is a typical neuroleptic belonging to the butyrophenones family.
It is a potent antagonist of brain dopaminergic receptors and, therefore, is classified among neuroleptics of great potency. It is the pattern with which antipsychotics of high antipsychotic potency are compared.
Haloperidol has no antihistamine or anticholinergic activity.
It is a drug less sedative than chlorpromazine and with frequent extrapyramidal symptoms, and has few anticholinergic and cardiotoxic effects.
CONTRAINDICATIONS
Haloperidol is contraindicated in patients with hypersensitivity to haloperidol, comatose state, central nervous system (CNS), depression caused by alcohol or other depressant medications, Parkinson's disease or injury to the basal ganglia.
CAUTIONS
Caution should be exercised when prescribing in cases of liver failure, renal failure, hyperthyroidism, angle-closure glaucoma, prostatic hypertrophy and urinary retention.
Caution should be exercised in patients with a history of prolonged cardiac QT syndrome, hypokalemia, electrolyte imbalance, treatment with QT prolonging substances, cardiovascular disease, family history of QT prolongation (especially when administered intramuscularly). The risk of QT prolongation and / or ventricular arrhythmias is increased with high doses of haloperidol. There is a risk of severe heart rhythm disturbances (especially when given intramuscularly).
Risk of neuroleptic malignant syndrome, tardive dyskinesia, extrapyramidal symptoms. Caution in patients with a history of epilepsy or other disorders predisposing to seizures (alcohol withdrawal and brain damage) or those patients susceptible to photosensitivity reactions.
Precautions should be taken when prescribing haloperidol in all age ranges, including the elderly and children.
SIDE EFFECTS
Agitation, insomnia, depression, psychotic disorder, extrapyramidal disorder, hyperkinesia, headache, tardive dyskinesia, oculogyric crisis, dystonia, dyskinesia, akathisia, bradykinesia, hypokinesia, hypertonia, somnolence, fascism parkinsoniana, tremor, dizziness, visual impairment, orthostatic hypotension, hypotension , constipation, dry mouth, salivary hypersecretion, nausea, vomiting, rash, urinary retention, erectile dysfunction, increase or decrease in weight.
PHARMACOLOGIC INTERACTIONS
Risk of Torsade de Pointes with substances that prolong the QT cardiac interval.
Increased plasma concentrations with itraconazole, nefazodone, buspirone, venlafaxine, alprazolam, fluvoxamine, quinidine, fluoxetine, sertraline, chlorpromazine and promethazine.
Plasma levels decreased by: carbamazepine, phenobarbital and rifampicin.
Haloperidol potentiates CNS depression of: alcohol, hypnotics, sedatives or potent analgesics.
It antagonizes the action of adrenaline.
Decreases the effect of levodopa.
Increases plasma levels of tricyclic antidepressants.
BRAND NAME
- Haldol ®
Genes analyzed
Bibliography
Beunk L, Nijenhuis M, Soree B, et al.Dutch Pharmacogenetics Working Group (DPWG) guideline for the gene-drug interaction between CYP2D6, CYP3A4 and CYP1A2 and antipsychotics. Eur J Hum Genet. 2024 Mar;32(3):278-285. doi: 10.1038/s41431-023-01347-3.
Dahl ML. Cytochrome p450 phenotyping/genotyping in patients receiving antipsychotics: useful aid to prescribing? Clin Pharmacokinet. 2002;41(7):453-70.
Spina E, de Leon J.Clinical applications of CYP genotyping in psychiatry. J Neural Transm (Vienna). 2015 Jan;122(1):5-28.