Ondansetron

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: Ondansetron

Examples of brand names: Zofran [DE]

ATC code: A04AA01

Main use (for orientation): Nausea; vomiting

Documented research summary

Clinical dronabinol/ondansetron experiment without additional combination success. Preclinical combinations show enhancement, blockade or no effect depending on model. These endpoints are neither general synergy nor clinical safety clearance.

Uncertainties and limitations

Original abstracts assessed; CBDA full text technically inaccessible, so no complete methods assessment claimed. Do not merge administration routes and different nausea/pain models. Missing data do not establish safety.

Separately recorded findings

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

THC (dronabinol) – clinically investigated

Finding ID: B0439

Type of result: Pharmacodynamics; assessed combination effect with no additional benefit

Observation: Dronabinol plus ondansetron showed no additional antiemetic benefit over individual treatments in this experiment.

Mechanism: Combined antiemetic therapy; not isolated pharmacokinetic assessment

Study type: Randomised controlled study

Context studied: Delayed chemotherapy-induced nausea/vomiting; 64 randomised, 61 in efficacy analysis. Total response: 54% dronabinol, 58% ondansetron, 47% combination, 20% placebo.

Clinical interpretation: Clinical combination test, but no dose/treatment recommendation or extrapolation to arbitrary cannabis products.

Limitations and uncertainties: Small study with a specific treatment regimen; null additional-benefit finding is not general proof of absent interaction or safety. Abstract assessed.

Original sources for this finding: Efficacy of dronabinol alone and in combination with ondansetron versus ondansetron alone for delayed chemotherapy-induced nausea and vomiting. [VE_MED_17355735]

CBDA – laboratory and animal studies

Finding ID: B0440

Type of result: Pharmacodynamics; enhancement in a conditioned-gaping model

Observation: The combination enhanced suppression of lithium-induced conditioned gaping: the low ondansetron amount was already effective alone, while CBDA alone was subthreshold.

Mechanism: 5-HT-related anti-nausea pharmacodynamics; not human pharmacokinetics

Study type: Rat experiment

Context studied: Rats; ondansetron 1 µg/kg and CBDA 0.1 µg/kg; experimental animal amounts, not transferable to humans.

Clinical interpretation: Hypothesis-generating preclinical combination effect.

Limitations and uncertainties: Original abstract read, full text technically unavailable. Conditioned gaping is a model, not clinical vomiting; not clinical safety evidence.

Original sources for this finding: Effect of low doses of cannabidiolic acid and ondansetron on LiCl-induced conditioned gaping (a model of nausea-induced behaviour) in rats. [VE_MED_23488964]

CBD – laboratory and animal studies

Finding ID: B0441

Type of result: Pharmacodynamics; experimental receptor blockade

Observation: Locally administered ondansetron prevented the antihypernociceptive CBD effect in the model investigated.

Mechanism: 5-HT3 receptor involvement in CBD antinociception in an amygdala context

Study type: Mouse experiment with intracerebral administration

Context studied: Male mice; empathy-induced hypernociception model; CBD 30/60 nmol and ondansetron 0.3 nmol intra-amygdala.

Clinical interpretation: Mechanistic animal finding, not general clinical CBD antagonism.

Limitations and uncertainties: Not an everyday oral combination, no systemic pair pharmacokinetics or human efficacy assessment. Original abstract read.

Original sources for this finding: The Reversal of Empathy-Induced Hypernociception in Male Mice by Intra-Amygdala Administration of Midazolam and Cannabidiol Depends on 5-HT3 Receptors. [VE_MED_36103283]

THC – laboratory and animal studies

Finding ID: B0442

Type of result: Pharmacodynamics; null finding under defined model conditions

Observation: Ondansetron did not suppress conditioned gaping induced by high THC exposure.

Mechanism: Assessment of 5-HT3 blockade against THC-induced nausea behaviour

Study type: Rat experiment

Context studied: Male rats; THC 10 mg/kg; ondansetron 0.01/0.1 mg/kg. These amounts describe the experiment only.

Clinical interpretation: Negative model result, not a general efficacy or safety rule.

Limitations and uncertainties: Animal behaviour and special exposure; not direct evidence concerning treatment or safety of human cannabinoid hyperemesis. Abstract assessed.

Original sources for this finding: Role of the stress response and the endocannabinoid system in Δ9-tetrahydrocannabinol (THC)-induced nausea. [BMED32399633]

THC – laboratory and animal studies

Finding ID: B0443

Type of result: Pharmacodynamics; enhanced antiemesis in an animal model

Observation: A combination of individually ineffective ondansetron and THC amounts suppressed vomiting and retching in the shrew model investigated.

Mechanism: Combined antiemetic effect in a cisplatin-induced vomiting model

Study type: Suncus murinus experiment

Context studied: Ondansetron 0.02 mg/kg plus THC 1.25 mg/kg before cisplatin; CBD investigated separately and not part of this combination.

Clinical interpretation: Limited preclinical combination effect; no clinical additional benefit can be inferred.

Limitations and uncertainties: Original abstract assessed. Not a human pharmacokinetic/safety study; do not use animal amounts as dosages. Do not interpret separate CBD results as CBD/ondansetron synergy.

Original sources for this finding: A comparative analysis of the potential of cannabinoids and ondansetron to suppress cisplatin-induced emesis in the Suncus murinus (house musk shrew). [VE_MED_14740147]

References and access status

[VE_LABEL_D0276] ONDANSETRON (ONDANSETRON HYDROCHLORIDE) TABLET, FILM COATED [MAJOR PHARMACEUTICALS]

Original source / bibliographic reference

Authors: Respective marketing authorisation holder; regulatory product information

Year: 2026

Source type: Product information / SmPC / US Prescribing Information

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

Bibliographic attribution or source identity cross-checked.

[VE_MED_17355735] Efficacy of dronabinol alone and in combination with ondansetron versus ondansetron alone for delayed chemotherapy-induced nausea and vomiting.

Original source / bibliographic reference

Authors: Meiri E, Jhangiani H, Vredenburgh JJ, Barbato LM, Carter FJ, Yang HM, Baranowski V.

Year: 2007

Source type: Comparative Study; Research Support, Non-U.S. Gov't; Randomized Controlled Trial; Journal Article

DOI: 10.1185/030079907x167525

PMID: 17355735

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.

PubMed – bibliographic reference / abstract

[VE_MED_23488964] Effect of low doses of cannabidiolic acid and ondansetron on LiCl-induced conditioned gaping (a model of nausea-induced behaviour) in rats.

Original source / bibliographic reference

Authors: Rock EM, Parker LA.

Year: 2013

Source type: Research Support, Non-U.S. Gov't; research-article; Journal Article

DOI: 10.1111/bph.12162

PMID: 23488964

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.

PubMed – bibliographic reference / abstract

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.

[VE_MED_36103283] The Reversal of Empathy-Induced Hypernociception in Male Mice by Intra-Amygdala Administration of Midazolam and Cannabidiol Depends on 5-HT3 Receptors.

Original source / bibliographic reference

Authors: Rodrigues Tavares LR, Baptista-de-Souza D, Canto-de-Souza L, Planeta CDS, Guimarães FS, Nunes-de-Souza RL, Canto-de-Souza A.

Year: 2023

Source type: Research Support, Non-U.S. Gov't; Journal Article

DOI: 10.1089/can.2022.0132

PMID: 36103283

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.

PubMed – bibliographic reference / abstract

[BMED32399633] Role of the stress response and the endocannabinoid system in Δ9-tetrahydrocannabinol (THC)-induced nausea.

Original source / bibliographic reference

Authors: DeVuono MV, La Caprara O, Sullivan MT, Bath A, Petrie GN, Limebeer CL, Rock EM, Hill MN, Parker LA.

Year: 2020

Source type: Publication; title and abstract reviewed

DOI: 10.1007/s00213-020-05529-5

PMID: 32399633

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.

PubMed – bibliographic reference / abstract

DOI – publisher access (access restrictions may apply)

[VE_MED_14740147] A comparative analysis of the potential of cannabinoids and ondansetron to suppress cisplatin-induced emesis in the Suncus murinus (house musk shrew).

Original source / bibliographic reference

Authors: Kwiatkowska M, Parker LA, Burton P, Mechoulam R.

Year: 2004

Source type: Comparative Study; Research Support, U.S. Gov't, P.H.S.; Research Support, Non-U.S. Gov't; Journal Article

DOI: 10.1007/s00213-003-1739-9

PMID: 14740147

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

Bibliographic attribution or source identity cross-checked.

PubMed – bibliographic reference / abstract

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