Haloperidol

For an informed discussion with your doctor or pharmacist. This information collection is not a clinically validated interaction checker. Missing data do not establish safety. Do not change or stop prescribed medicines on the basis of this information. The findings apply to the specific conditions studied; laboratory and animal studies cannot be directly extrapolated to humans.

Active substance: Haloperidol

Examples of brand names: Haldol [DE]

ATC code: N05AD01

Main use (for orientation): Psychoses; delirium

Documented research summary

A human study showed greater impairment of memory/attention with joint exposure. Case reports and hyperemesis treatment must be assessed separately.

Uncertainties and limitations

The 2019 responder analysis is a secondary analysis of the 2008 study, not independent confirmation. Acute intravenous THC challenge is not chronic cannabis use. QT risk in cannabinoid hyperemesis syndrome must not be attributed to a cannabinoid alone.

Research is limited to the specified date and protocol; it is not globally exhaustive. Brand names and authorisations do not constitute a complete current market overview.

Structured assessment

Category: Direct pair finding

Cannabinoid scope: 28 register names in the documented search family; neither 28 individual clinical trials nor a blanket assessment of all cannabinoids.

Evidence status: Pair-specific evidence, distinguished in the individual findings

Mechanism / drug context: Controlled THC challenge; additional confounded cardiac case signals.

Type of supporting material: See the separate original findings

Clinical interpretation: Requires individual assessment by a doctor or pharmacist. Lack of evidence does not establish safety; no dosage or discontinuation advice is provided.

Context: Haloperidol lactate injection; active haloperidol base, not a prodrug. US label not approved for intravenous use; consider the study route separately.

Drug context and gaps in search results are not measured interactions. The source role below describes which statement the source actually supports.

Source role [CA_L_D0130]: Drug context

Statement supported: Supports dosage form, metabolism and/or known risks; alone, it does not substantiate a cannabinoid–drug pair finding.

Source: HALOPERIDOL (HALOPERIDOL LACTATE) INJECTION, SOLUTION [FRESENIUS KABI USA, LLC] [CA_L_D0130]

Source role [CA_P_18228005]: Pair finding

Statement supported: Joint exposure increased memory/attention impairment.

Source: Effects of haloperidol on the behavioral, subjective, cognitive, motor, and neuroendocrine effects of Delta-9-tetrahydrocannabinol in humans. [CA_P_18228005]

Source role [CA_P_39502532]: Pair finding

Statement supported: Ventricular arrhythmia with QTc prolongation reported.

Source: Green rush and red warnings: Retrospective chart review of adverse events of interactions between cannabinoids and psychotropic drugs. [CA_P_39502532]

Scope of review: Individual research with documented title/abstract screening and targeted review of original sections. This is not exhaustive evidence that interactions are absent.

Unresolved source question: The complete stored individual review, label review, literature screening, conclusion and uncertainties were read. Targeted sections of original information were rechecked; no claim is made that all product information or full texts were completely revalidated.

Separately recorded findings

2 separately recorded findings. Each statement applies to its documented study context.

Δ9-THC – clinically investigated

Finding ID: V6_D0130_1

Type of result: Finding within the documented study context

Observation: Joint exposure increased memory/attention impairment.

Mechanism: Pharmacodynamic interaction

Study type: Double-blind human experiment

Context studied: 28 participants; oral haloperidol and intravenous THC, D’Souza et al. 2008.

Clinical interpretation: Functional risks.

Limitations and uncertainties: Not usual outpatient exposure; do not count the later subgroup analysis independently.

Original sources for this finding: Effects of haloperidol on the behavioral, subjective, cognitive, motor, and neuroendocrine effects of Delta-9-tetrahydrocannabinol in humans. [CA_P_18228005]

THC-rich cannabis products – clinical signals

Finding ID: V6_D0130_2

Type of result: Finding within the documented study context

Observation: Ventricular arrhythmia with QTc prolongation reported.

Mechanism: Mechanism uncertain

Study type: Retrospective case series

Context studied: Chrobak et al. 2024.

Clinical interpretation: Cardiac warning signal.

Limitations and uncertainties: Several concomitant medicines; no isolated exposure/enzyme measurement.

Original sources for this finding: Green rush and red warnings: Retrospective chart review of adverse events of interactions between cannabinoids and psychotropic drugs. [CA_P_39502532]

References and access status

[CA_L_D0130] HALOPERIDOL (HALOPERIDOL LACTATE) INJECTION, SOLUTION [FRESENIUS KABI USA, LLC]

Original source / bibliographic reference

Authors: Fresenius Kabi USA, LLC

Year: 2026

Source type: Current published human-use SPL / product information

Source access – 23 October 2026: Source destination was accessible when checked.

Bibliographic attribution or source identity cross-checked.

[CA_P_39502532] Green rush and red warnings: Retrospective chart review of adverse events of interactions between cannabinoids and psychotropic drugs.

Original source / bibliographic reference

Authors: Chrobak AA, Woroń J, Siwek M.

Year: 2024

Source type: research-article; Journal Article

DOI: 10.3389/fphar.2024.1500312

PMID: 39502532

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

PubMed Central – full-text access according to the literature database – Archive attribution confirmed by Europe PMC metadata. Direct retrieval was not fully verified here; access may require a browser check.

Europe PMC – full-text access according to the literature database – Listed as freely available HTML full text in the official Europe PMC metadata. Direct retrieval was not fully verified here.

[CA_P_39699828] Cannabigerol Mitigates Haloperidol-Induced Vacuous Chewing Movements in Mice.

Original source / bibliographic reference

Authors: Ponciano R, Hallak JEC, Crippa JA, Guimarães FS, Bel EAD.

Year: 2024

Source type: Journal Article

DOI: 10.1007/s12640-024-00724-0

PMID: 39699828

Source access – 23 October 2026: Automated direct retrieval was restricted; this does not establish that the link is broken.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[CA_P_39797246] Mitigating the Risk of QTc Prolongation When Using Haloperidol for Acute Treatment of Cannabinoid Hyperemesis Syndrome in Adolescents and Young Adults.

Original source / bibliographic reference

Authors: Merino S, Tordera L, Jun A, Yang S.

Year: 2024

Source type: research-article; Journal Article

DOI: 10.3390/jcm14010163

PMID: 39797246

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

PubMed Central – full-text access according to the literature database – Archive attribution confirmed by Europe PMC metadata. Direct retrieval was not fully verified here; access may require a browser check.

Europe PMC – full-text access according to the literature database – Listed as freely available HTML full text in the official Europe PMC metadata. Direct retrieval was not fully verified here.

[CA_P_30919005] Effects of haloperidol on the delta-9-tetrahydrocannabinol response in humans: a responder analysis.

Original source / bibliographic reference

Authors: Gupta S, De Aquino JP, D'Souza DC, Ranganathan M.

Year: 2019

Source type: research-article; Journal Article

DOI: 10.1007/s00213-019-05235-x

PMID: 30919005

Source access – 23 October 2026: Automated direct retrieval was restricted; this does not establish that the link is broken.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

PubMed Central – full-text access according to the literature database – Archive attribution confirmed by Europe PMC metadata. Direct retrieval was not fully verified here; access may require a browser check.

Europe PMC – full-text access according to the literature database – Listed as freely available HTML full text in the official Europe PMC metadata. Direct retrieval was not fully verified here.

[CA_P_33160719] Intravenous Haloperidol Versus Ondansetron for Cannabis Hyperemesis Syndrome (HaVOC): A Randomized, Controlled Trial.

Original source / bibliographic reference

Authors: Ruberto AJ, Sivilotti MLA, Forrester S, Hall AK, Crawford FM, Day AG.

Year: 2021

Source type: Randomized Controlled Trial; Journal Article

DOI: 10.1016/j.annemergmed.2020.08.021

PMID: 33160719

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[CA_P_20142302] Central nervous system effects of haloperidol on THC in healthy male volunteers.

Original source / bibliographic reference

Authors: Liem-Moolenaar M, te Beek ET, de Kam ML, Franson KL, Kahn RS, Hijman R, Touw D, van Gerven JM.

Year: 2010

Source type: Randomized Controlled Trial; Journal Article

DOI: 10.1177/0269881109358200

PMID: 20142302

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[CA_P_18228005] Effects of haloperidol on the behavioral, subjective, cognitive, motor, and neuroendocrine effects of Delta-9-tetrahydrocannabinol in humans.

Original source / bibliographic reference

Authors: D'Souza DC, Braley G, Blaise R, Vendetti M, Oliver S, Pittman B, Ranganathan M, Bhakta S, Zimolo Z, Cooper T, Perry E.

Year: 2008

Source type: Research Support, Non-U.S. Gov't; research-article; Research Support, U.S. Gov't, Non-P.H.S.; Journal Article; Research Support, N.I.H., Extramural

DOI: 10.1007/s00213-007-1042-2

PMID: 18228005

Source access – 23 October 2026: Source destination was accessible when checked.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

Research as of 23 October 2026. Not all original full texts could be reviewed in full. Source accessibility and the strength of scientific evidence must be assessed separately. An accessible link does not establish medical approval; a bibliographic record with an abstract does not replace the original full text.

Drug search and explanation of the evidence · Guide: cannabinoids and medicines · Author and responsibility