ArticleEuropean journal of pain (London, England)2026
Repeated Tetrahydrocannabinol Injections Induce Tolerance but Do Not Disrupt Ongoing Behaviour Upon Withdrawal in Male and Female Rats With Inflammatory Pain.
Article in European journal of pain (London, England), 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
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.
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.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
2 authors.
Funding
Abstract
backgroundMany people use cannabis to self-medicate for pain. Little is known about the impact of pain on tolerance and spontaneous withdrawal to delta-9-tetrahydrocannabinal (THC), the primary psychoactive compound in cannabis. Our previous research with the opioid morphine suggests persistent pain will increase the magnitude and duration of THC withdrawal.
methodsMale and female Sprague-Dawley rats were individually housed in a cage with a running wheel to provide a continuous and objective measure of well-being. All rats were injected with Complete Freund's Adjuvant (CFA) into the right hindpaw to induce inflammatory pain. Beginning 1 day later, rats received twice daily THC or vehicle injections for 7 days followed by assessment of tolerance and spontaneous withdrawal.
resultsAdministration of CFA decreased wheel running. Twice daily injections of THC (3 mg/kg/injection) caused a further reduction in running in male and female rats. Tolerance to the THC-induced decrease in running was more pronounced in male compared to female rats. There was no evidence of spontaneous withdrawal to THC despite continuous assessment for 6 days. Likewise, withdrawal had no effect on body weight.
conclusionThe lack of spontaneous withdrawal in rats with hindpaw inflammation is consistent with our recent study showing a lack of spontaneous withdrawal to THC in pain free rats, but opposite to our opioid research showing enhancement of spontaneous withdrawal to morphine in rats with hindpaw inflammation. In sum, persistent inflammatory pain does not appear to alter the effects of repeated THC injections in male or female rats. SIGNIFICANCE: The use of THC as a treatment for pain is limited by side effects and tolerance but not by dependence associated withdrawal symptoms.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
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.