InfoSynergy
Magnesium Glycinate
Magnesium deficiency can worsen torsades risk in patients receiving QT-prolonging drugs such as haloperidol.
Recommendation: Correct low magnesium under clinician guidance when QT risk factors are present.
Haloperidol
Prescription ·Strong evidence ·Reviewed May 2026
Haloperidol is a high-potency first-generation antipsychotic used for schizophrenia, Tourette disorder, and acute agitation or delirium-related severe behavioral disturbance when clinically appropriate. It has substantial extrapyramidal, tardive dyskinesia, neuroleptic malignant syndrome, and QT-prolongation risks, especially with high doses or parenteral use. It carries a boxed warning for increased mortality in elderly patients with dementia-related psychosis.
What it's good for
The bottom line
Evidence rating strong. Most-documented uses: treatment of schizophrenia, control of tics and vocal utterances in tourette disorder, short-term management of severe acute agitation when benefits outweigh risks. 3 sources indexed (2020–2026), with 4 interaction records on file.
The science
How it works, mechanistically.
Core mechanism
Haloperidol primarily antagonizes dopamine D2 receptors in mesolimbic and nigrostriatal pathways, producing antipsychotic effects and extrapyramidal adverse effects. It has less anticholinergic and antihistaminic activity than low-potency antipsychotics but can cause marked dopamine blockade, hyperprolactinemia, akathisia, dystonia, parkinsonism, and tardive dyskinesia. Cardiac potassium-channel effects contribute to QT prolongation and torsades risk, especially with IV use, high doses, electrolyte abnormalities, or other QT-prolonging drugs.2,3
Class
First-generation antipsychotic
Dosing
Dosing & protocol.
Common range
Oral dosing is individualized; common adult starting ranges are 0.5-5 mg two or three times daily, with lower dosing in older or medically frail patients. Decanoate dosing is based on prior stable oral dose and clinical response.
Recommended form
Oral tablet or solution, short-acting injection for acute use, or decanoate injection for maintenance after oral tolerability
Oral haloperidol can be taken with or without food. Avoid alcohol and use caution with other sedating agents.
Safety
Full safety detail.
Side effects
- Akathisia
- Dystonia
- Parkinsonism
- Tardive dyskinesia
- Hyperprolactinemia
- Sedation
- Orthostatic hypotension
- QT prolongation and torsades de pointes
- Neuroleptic malignant syndrome
- Seizures in susceptible patients
- Anticholinergic effects, less prominent than low-potency agents
Interactions
Interaction records.
InfoSynergy
Potassium
Hypokalemia increases risk of QT-related ventricular arrhythmias during haloperidol therapy.
Recommendation: Correct hypokalemia medically and avoid unsupervised potassium supplementation in kidney disease or with potassium-retaining drugs.
ModerateCaution
Melatonin
Melatonin can add to haloperidol-related sedation, dizziness, and psychomotor impairment.
Recommendation: Use cautiously and monitor for falls or next-day impairment.
ModerateCaution
Ginkgo Biloba
Ginkgo has seizure case reports, and haloperidol can lower seizure threshold in susceptible patients.
Recommendation: Avoid or use cautiously in patients with seizure disorders or other seizure-threshold-lowering exposures.
Sources
Sources, by evidence tier.
Numbered references. Citations throughout the page link here.
Reviews & position papers
1- 1The American Psychiatric Association practice guideline for the treatment of patients with schizophreniaNeeds reviewNo linkAmerican Psychiatric Association · American Journal of Psychiatry · 2020
Guideline supports monitoring antipsychotic efficacy, abnormal movements, metabolic parameters, and cardiovascular risk.
Reference material
2- 2HALOPERIDOL DECANOATE injection, US Prescribing InformationNeeds reviewURLU.S. National Library of Medicine · DailyMed · 2026
Decanoate labeling describes maintenance use in adults previously stabilized on immediate-release haloperidol.
- 3HALOPERIDOL tablets, US Prescribing InformationNeeds reviewURLU.S. National Library of Medicine · DailyMed · 2025
Labeling lists contraindications, dementia-related psychosis boxed warning, QT risk, and extrapyramidal adverse effects.
Keep exploring
Deep dives & adjacent profiles.
This page is educational. Do not start, stop, or change a supplement or medication based on it without checking with a qualified healthcare professional.
Use this with your stack
Haloperidol in NutriStack.
Add it to your stack, see how it interacts with everything else you take, and get a Stack Score that updates the moment it does.