Evidence map›Paper›PMID 15778704›Full record

ArticleBritish journal of pharmacology2005

Synergistic and additive interactions of the cannabinoid agonist CP55,940 with mu opioid receptor and alpha2-adrenoceptor agonists in acute pain models in mice.

Shao M Tham, James A Angus, Elizabeth M Tudor, Christine E Wright

Open access · greenAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in British journal of pharmacology, 2005. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 47 papers, 3 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
47citing papers in PubMed, 3 pooled it
2.6field-weighted citation impact, top 11% 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

47 citing papers in PubMed, 3 syntheses or guidelines pooled it, 97 citations in OpenAlex.

  1. Opioid-sparing effect of cannabinoids for analgesia: an updated systematic review and meta-analysis of preclinical and clinical studies.Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology · 2022
    Pooled it
  2. Opioid-Sparing Effect of Cannabinoids: A Systematic Review and Meta-Analysis.Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology · 2017
    Pooled it
  3. Pooled it
  4. Review
  5. Cannabinoid CB1 receptor and mu-opioid receptor interaction: new insights from conditional knockout mice.Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology · 2026
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  15. αPharmacological reports : PR · 2020
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  17. Cannabis-based medicines and the perioperative physician.Perioperative medicine (London, England) · 2019
    Review
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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

4 authors at 1 institution in 1 country.

Shao M ThamCardiovascular Therapeutics Unit, Department of Pharmacology, University of Melbourne, Victoria 3010, Australia.
James A Angus
Elizabeth M Tudor
Christine E Wright
University of Melbourne · AU

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

1. Cannabinoid receptor agonists elicit analgesic effects in acute and chronic pain states via spinal and supraspinal pathways. We investigated whether the combination of a cannabinoid agonist with other classes of antinociceptive drugs exerted supra-additive (synergistic) or additive effects in acute pain models in mice. 2. The interactions between the cannabinoid agonist CP55,940, alpha2-adrenoceptor agonist dexmedetomidine and mu-opioid receptor agonist morphine were evaluated by isobolographic analysis of antinociception in hot plate (55 degrees C) and tail flick assays in conscious male Swiss mice. Drug interactions were examined by administering fixed-ratio combinations of agonists (s.c.) in 1:1, 3:1 and 1:3 ratios of their respective ED50 fractions. 3. CP55,940, dexmedetomidine and morphine all caused dose-dependent antinociception. In the hot plate and tail flick assays, ED50 values (mg kg(-1)) were CP55,940 1.13 and 0.51, dexmedetomidine 0.066 and 0.023, and morphine 29.4 and 11.3, respectively. Synergistic interactions existed between CP55,940 and dexmedetomidine in the hot plate assay, and CP55,940 and morphine in both assays. Additive interactions were found for CP55,940 and dexmedetomidine in the tail flick assay, and dexmedetomidine and morphine in both assays. 4. Thus, an alpha2-adrenoceptor agonist or mu opioid receptor agonist when combined with a cannabinoid receptor agonist showed significant synergy in antinociception in the hot plate test. However, for the tail flick nociceptive response to heat, only cannabinoid and mu opioid receptor antinociceptive synergy was demonstrated. If these results translate to humans, then prudent selection of dose and receptor-specific agonists may allow an improved therapeutic separation from unwanted side effects.

Indexed as

Acute DiseaseAdrenergic alpha-AgonistsAnalgesicsAnalgesics, Non-NarcoticAnalgesics, OpioidAnimalsCannabinoidsCyclohexanolsDexmedetomidineDose-Response Relationship, DrugDrug SynergismInjections, SpinalMaleMiceMorphinePain3-(2-hydroxy-4-(1,1-dimethylheptyl)phenyl)-4-(3-hydroxypropyl)cyclohexanolAdrenergic alpha-AgonistsAnalgesicsAnalgesics, Non-NarcoticAnalgesics, OpioidCannabinoidsCyclohexanolsDexmedetomidineMorphineReceptors, Opioid, mu

Identifiers

PMID15778704
PMCPMC1576059
OpenAlexW1987722050

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.