Evidence map›Paper›PMID 29953631›Full record

SynthesisBritish journal of clinical pharmacology2018

Cannabis contaminants: sources, distribution, human toxicity and pharmacologic effects.

Laura M Dryburgh, Nanthi S Bolan, Christopher P L Grof, Peter Galettis, Jennifer Schneider, Catherine J Lucas, Jennifer H Martin

Open access · bronzeAbstract readSystematic Review
PubMed Full text at PMC Publisher
In one paragraph

Synthesis in British journal of clinical pharmacology, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 63 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
63citing papers in PubMed, 1 pooled it
9.8field-weighted citation impact, top 1% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

63 citing papers in PubMed, 1 synthesis or guideline pooled it, 153 citations in OpenAlex.

  1. Pooled it
  2. Effects of SativexNutrients · 2026
    Trial
  3. Trial
  4. Article
  5. Review
  6. Article
  7. Review
  8. Article
  9. Article
  10. Article
  11. Review
  12. Article
  13. Genotoxicity study ofToxicology reports · 2025
    Review
  14. Article
  15. Entomopathogenic Fungi Effectively ControlPlants (Basel, Switzerland) · 2025
    Article
  16. Article
  17. Article
  18. Article
  19. Article
  20. Article

3 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors at 3 institutions in 1 country.

Laura M DryburghSchool of Medicine and Public Health, Faculty of Health and Medicine, The University of Newcastle, Australia.ORCID 0000-0002-8795-5066
Nanthi S BolanThe Australian Centre for Cannabinoid Clinical and Research Excellence, The University of Newcastle, Australia.ORCID 0000-0003-2056-1692
Christopher P L GrofThe Australian Centre for Cannabinoid Clinical and Research Excellence, The University of Newcastle, Australia.ORCID 0000-0003-1968-5401
Peter GalettisSchool of Medicine and Public Health, Faculty of Health and Medicine, The University of Newcastle, Australia.ORCID 0000-0002-6785-2529
Jennifer SchneiderHunter Medical Research Institute, New Lambton, NSW, Australia.ORCID 0000-0002-3473-8009
Catherine J LucasSchool of Medicine and Public Health, Faculty of Health and Medicine, The University of Newcastle, Australia.ORCID 0000-0002-8126-5582
Jennifer H MartinSchool of Medicine and Public Health, Faculty of Health and Medicine, The University of Newcastle, Australia.ORCID 0000-0002-8614-0199
Hunter Medical Research Institute · AUNew South Wales Department of Health · AUUniversity of Newcastle Australia · AU

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

There has been a resurgence in interest and use of the cannabis plant for medical purposes. However, an in-depth understanding of plant contaminants and toxin effects on stability of plant compounds and human bioavailability is needed. This systematic review aims to assess current understanding of the contaminants of cannabis and their effect on human health, leading to the identification of knowledge gaps for future investigation. A systematic search of seven indexed biological and biomedical databases and the Cochrane library was undertaken from inception up to December 2017. A qualitative synthesis of filtered results was undertaken after independent assessment for eligibility by two reviewers. The common cannabis contaminants include microbes, heavy metals and pesticides. Their direct human toxicity is poorly quantified but include infection, carcinogenicity, reproductive and developmental impacts. Cannabis dosing formulations and administration routes affect the transformation and bioavailability of contaminants. There may be important pharmacokinetic interactions between the alkaloid active ingredients of cannabis (i.e. phytocannabinoids) and contaminants but these are not yet identified nor quantified. There is significant paucity in the literature describing the prevalence and human impact of cannabis contaminants. Advances in the availability of cannabis globally warrant further research in this area, particularly when being used for patients.

Indexed as

AnimalsCannabinoidsCannabisDrug ContaminationEnvironmental ExposureEnvironmental PollutionHumansMetals, HeavyPesticidesPlant ExtractsCannabinoidsMetals, HeavyPesticidesPlant Extractsaddiction medicinecannabinoidsmolecular biologypharmacokinetics

Identifiers

PMID29953631
PMCPMC6177718
OpenAlexW2810962749

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.