Category Archives: Chronic Pain

The Pharmacology of Cannabinoids in Chronic Pain

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“Background: Our objective was to provide an overview of the currently available scientific and clinical data supporting the use of Cannabis and Cannabis-derived products for the treatment of chronic pain disorders. We also provide information for researchers, clinicians, and patients to be better informed and understand the approach behind the recommendation of Cannabis as a potential adjuvant in the treatment/control of chronic pain. Cannabis and its bioactive compounds have sparked interest in the field of pain treatment in spite of its controversial history and status as a controlled substance in many countries. With the increase in chronic pain, physicians and patients have started to look at alternative ways to treat pain aside from traditional treatments. One alternative is the use of cannabis to reduce/treat chronic pain disorders based on anecdotal accounts and the function of its phytocannabinoids. The two main cannabinoids in cannabis, tetrahydrocannabinol (THC) and cannabidiol, act on CB1 and CB2 receptors (in addition to several additional receptors). It is through these pleiotropic receptor interactions that these compounds elicit their biological function including the reduction of chronic pain. In this narrative review, we included the most recent evidence supporting the use of cannabis in the treatment of chronic pain disorders including chronic neuropathic pain, cancer-induced neuropathic pain, chronic musculoskeletal pain, and chronic headaches and migraines.

Summary: Evidence suggests that cannabis and cannabinoids have an analgesic effect that arises from a combination of compounds and various receptor systems. These effects may be maximized with the use of a combination of cannabinoids. At the same time, the combination of cannabinoids helps minimize the undesirable side effects of some cannabinoids such as the psychoactivity of THC. With these findings, further research is necessary to assess the analgesic properties of other cannabinoids like cannabichromene and cannabigerol and their contributions to the reduction of pain.”

https://pubmed.ncbi.nlm.nih.gov/40046175/

“Cannabis sativa L. has been used as a medicinal remedy for thousands of years. It has gone through multiple periods of acceptance, dismissal/rejection, reacceptance, illegality and, most recently, rediscovery of its potential to address chronic medical conditions. In the last few decades, its recreational use has received growing acceptance, while its medical use has been encouraged in multiple jurisdictions. Most modern research has focused on the phytocannabinoids produced by the plant which have been found to help minimize chronic neuropathic pain and mitigate other disorders including seizure conditions (e.g., Lennox-Gastaut and Dravet syndromes) and spasticity in MS. This review has provided scientific evidence supporting the use of cannabis as an adjuvant in the treatment of chronic pain which could also lead pain reduction to the point of minimizing other pharmacological treatments.”

https://karger.com/mca/article/8/1/31/920366/The-Pharmacology-of-Cannabinoids-in-Chronic-Pain

“Designer cannabinoids could be the key to pain relief without adverse effects”

https://www.nature.com/articles/d41586-025-00546-w

A within-subject, double-blind, placebo-controlled randomized evaluation of the combined effects of cannabidiol and hydromorphone in a human laboratory pain model

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“Preclinical and epidemiological evidence supports that cannabinoids may have opioid-sparing properties and could be one strategy to decrease opioid use and associated harms like overdose and extramedical use.

The objective of this within subjects, double-blind, double-dummy, randomized human laboratory trial was to examine whether cannabidiol (CBD) increases opioid analgesic effects and whether there are corresponding increases in other opioid mediated effects.

Healthy participants (N = 31) attended 5 outpatient sessions where they received the following drug conditions: (1) placebo + placebo, (2) 4 mg hydromorphone + placebo, (3) 4 mg hydromorphone + 50 mg CBD, (4) 4 mg hydromorphone + 100 mg CBD, and (5) 4 mg hydromorphone + 200 mg CBD. Before and at multiple time points after drug administration, participants completed (1) quantitative sensory testing, which induced and assessed acute and chronic laboratory models of pain; (2) standard assessments, which queried acute subjective drug effects; and (3) tasks, which assessed psychomotor performance.

When combined with a dose of hydromorphone that did not reliably produce analgesic effects on its own, CBD increased the analgesic effects for some laboratory acute pain outcomes but none of the laboratory chronic pain outcomes. At the highest dose of CBD (200 mg), there were concurrent increases in self-report Bad Effects and adverse effects that were not observed at lower doses of CBD (50 mg). Cannabidiol mitigated psychomotor impairment observed with hydromorphone alone.

These findings suggest that lower doses of CBD (50 mg) may have utility for enhancing acute analgesic properties of opioids without having corresponding increases in bad effects.”

https://pubmed.ncbi.nlm.nih.gov/40035623/

https://journals.lww.com/pain/abstract/9900/a_within_subject,_double_blind,_placebo_controlled.840.aspx

Cannabis use and illicit opioid cessation among people who use drugs living with chronic pain

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“Introduction: Amidst the opioid overdose crisis, there is interest in cannabis use for pain management and harm reduction. We investigated the relationship between cannabis use and cessation of unregulated opioid use among people who use drugs (PWUD) living with chronic pain.

Method: Data for analyses were collected from three prospective cohort studies in Vancouver, Canada. All cohort participants who completed at least two study visits and reported both pain and unregulated opioid use in the past 6 months were included in the present study. We analysed the association between cannabis use frequency and opioid cessation rates using extended Cox regression models with time-updated covariates.

Results: Between June 2014 and May 2022, 2340 PWUD were initially recruited and of those 1242 PWUD reported chronic pain, use of unregulated opioids and completed at least two follow-up visits. Of these 1242 participants, 764 experienced a cessation event over 1038.2 person-years resulting in a cessation rate of 28.5 per 100 person-years (95% confidence interval [CI] 25.4-31.9). Daily cannabis use was positively associated with opioid cessation (adjusted hazard ratio 1.40, 95% CI 1.08-1.81; p = 0.011). In the sex-stratified sub-analyses, daily cannabis use was significantly associated with increased rates of opioid cessation among males (adjusted hazard ratio 1.50, 95% CI 1.09-2.08; p = 0.014).

Discussion and conclusions: Participants reporting daily cannabis use exhibited higher rates of cessation compared to less frequent users or non-users. Observed sex-specific differences in cannabis use and opioid cessation suggest potential differences in cannabis use behaviours and effects. Our findings add to the growing evidence supporting the potential benefits of cannabis use among PWUD, underlining the need for further research.”

https://pubmed.ncbi.nlm.nih.gov/40011075/

Moroccan Cannabis sativa essential oil attenuates peripheral neuropathic pain induced by chronic sciatic nerve constriction injury in mice

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“Ethnopharmacological relevance: Cannabis sativa has been widely used in traditional medicine for its therapeutic properties. However, in Morocco, the ethnobotanical applications of Cannabis sativa, especially its essential oils, are underexplored. This study investigates, for the first time, the effects of Moroccan Cannabis sativa essential oil on peripheral neuropathic pain.

Materials and methods: Peripheral neuropathic pain was induced in mice through sciatic nerve injury. The mice were treated daily with cannabis essential oil for 21 days. Behavioral tests were conducted on days 1, 7, 14, and 21 to evaluate thermal, mechanical, and cold sensitivity. The essential oil’s chemical composition was analyzed using gas chromatography-mass spectrometry (GC/MS).

Results: The main constituents of the essential oil were (E)-caryophyllene (41.59%) and α-humulene (14%). Daily treatment with the essential oil significantly reduced pain sensitivity and improved functional and histological recovery over time. These effects are linked to the activity of the dominant terpenoids in the oil.

Conclusion: Moroccan Cannabis sativa essential oil shows significant therapeutic potential for managing peripheral neuropathic pain. By enhancing recovery and alleviating pain symptoms, it offers a promising alternative for treating chronic pain caused by nerve injuries.”

https://pubmed.ncbi.nlm.nih.gov/39947371/

“A multitude of recent studies have explored the broad biological properties of cannabis. Extracts from Cannabis sativa have demonstrated antimicrobial, anti-inflammatory, antinociceptive, and potent antioxidant activities.”

“This study examined the analgesic effects of terpenes found in Cannabis sativa essential oil on neuropathy. The results showed that chronic administration of these bioactive terpenes, specifically β-caryophyllene, α-humulene, and caryophyllene oxide, significantly increased pain sensitivity and response time in mice with neuropathy. Although morphine and THC-based treatments are commonly used to relieve neuropathic pain, these terpenes may offer a promising alternative with limited side effects. Clinical research has demonstrated the efficacy of cannabis-based treatments, leading several pain societies to recommend them for neuropathy management. “

https://www.sciencedirect.com/science/article/pii/S0378874125001692?via%3Dihub

The cannabinoid CB2 receptor mediates the analgesic effects of Cannabis sativa extract in a rat model of neuropathic pain

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“Neuropathic pain (NP) is a complex and debilitating condition that is often refractory to currently available analgesic medications.

Cannabis sativa extract (CSE) has been reported to exhibit analgesic properties across various pain models; however, the underlying mechanisms of action are not fully understood.

This study aimed to investigate the involvement of the cannabinoid CB2 receptor in mediating the analgesic effects of CSE in a rat model of NP, where NP was induced in male Wistar rats through chronic constriction injury (CCI) of the sciatic nerve.

Rats were randomly allocated into four groups: (1) Sham + vehicle, (2) CCI + vehicle, (3) CCI + CSE, and (4) CCI + CSE + AM630 (a CB2 receptor antagonist). CSE was administered intraperitoneally at a dosage of 30mg/kg once daily for 7 days, starting from day 7 to day 13 post-CCI surgery. To assess the involvement of the CB2 receptor, 7µg of AM630 was administered intrathecally to the rats in group 4, 30minutes before the CSE injections. Mechanical allodynia and thermal hyperalgesia were assessed using the von Frey filament and hot plate tests, respectively, at baseline (day 0) and on days 3, 7, 10, and 14 after surgery. Additionally, at the end of the study period (day 14), the expression level of Iba1 and GFAP genes was quantified in the lumbar enlargement tissues using real-time PCR.

The results demonstrated that CCI surgery induced mechanical allodynia and thermal hyperalgesia, along with the upregulation of Iba1 and GFAP genes in the vehicle-treated CCI group. Treatment with CSE significantly mitigated both allodynia and hyperalgesia and downregulated the expression of Iba1 and GFAP genes compared to the CCI + vehicle group. Furthermore, the administration of the CB2 receptor antagonist AM630 not only robustly blocked the antinociceptive effects of CSE but also reversed the significant downregulation of Iba1 and GFAP gene expression in the lumbar enlargement tissues.

These findings highlight the novel role of the CB2 receptor in mediating the analgesic effects of CSE, providing new insights into the potential therapeutic mechanisms of CSE in neuropathic pain management.”

https://pubmed.ncbi.nlm.nih.gov/39947333/

“In summary, this study provides evidence that CSE exerts analgesic and anti-inflammatory effects in NP through CB2 receptor activation. These findings contribute to the growing body of research supporting cannabinoids as potential therapeutic agents for NP management.”

https://www.sciencedirect.com/science/article/abs/pii/S0166432825000683?via%3Dihub

Cannabidiol interactions with oxycodone analgesia in an operant orofacial cutaneous thermal pain assay following oral administration in rats

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“Previous studies have driven the notion that the cannabis constituent cannabidiol could be an effective adjunct to opioid administration for managing pain.

Most of these studies have used experimental rodents with routes of administration, such as subcutaneous and intraperitoneal, that do not correspond with the routes used in clinical practice. In response to this, we tested the ability of cannabidiol co-administration to augment opioid analgesia via the more clinically-relevant oral route of administration.

To this end, male and female rats were orally gavaged with cannabidiol (25 mg/kg), oxycodone (1.4 mg/kg), or a combination of both, after which they were tested in an operant thermal orofacial pain assay in which they voluntarily exposed their faces to cutaneous thermal pain to receive a palatable reward.

All three drug conditions produced analgesic effects of varying degrees, being most profound in the combination group where a statistically significant enhancement over oxycodone-induced analgesia alone was evident. Additionally, oxycodone administration decreased lick frequencies – a measure of motor coordination of rhythmic movements – which too was magnified by co-administration of cannabidiol.

Together these studies provide further support of an ability of cannabidiol to augment opioid effects, particularly analgesia, when administered by a route relevant to human pain management. As such, they encourage the notion that cannabidiol could find utility as an opioid-sparing approach to treating pain.”

https://pubmed.ncbi.nlm.nih.gov/39914591/

“Cannabidiol is an orally active constituent of the cannabis plant”

“Cannabidiol potentiates opioid analgesia in an operant orofacial pain assay in rats”

“Cannabidiol as an opioid-sparing approach to treating pain is worthy of more study”

https://www.sciencedirect.com/science/article/abs/pii/S0091305725000152?via%3Dihub

The comparative effectiveness of medicinal cannabis for chronic pain versus prescription medication treatment

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“Reviews of the effectiveness of medicinal cannabis for chronic pain vary in their conclusions. IASP has identified that a key missing evidence in this debate is data from observational cohort studies, analyzed with comparative effectiveness methods.

In a medically supervised context to the use of marijuana for chronic pain, we identified 440 patients certified for medical marijuana by pain specialists in a single healthcare system. They were characterized by a battery of patient-reported outcomes stored electronically in the University of Pittsburgh Patient Outcomes Repository for Treatment (PORT).

At 3 months, 38.6% were responders, based on clinically meaningful improvements in pain, function, or global impression of change, and maintained this response at 6 months. In the 157 patients who were coprescribed opioids, at 6 months there was a mean 39.3% decrease in morphine milligram equivalents (P < 0.05 for the difference vs baseline).

In addition, 8114 patients treated in the same pain clinics with prescription pain medications instead (nonopioid or opioid) during the same timeframe were selected from PORT as a control group for comparison. They had a 34.9% rate of response at 3 months. Using the causal inference method of stratified modeling, logistic regression revealed an odds ratio of 2.6 in favor of medical marijuana vs medication treatment (P < 0.01). Potential harms data were not available in the PORT registry.

Medical marijuana was comparatively more effective than prescription medications for the treatment of chronic pain at 3 months, although the populations compared were slightly different.”

https://pubmed.ncbi.nlm.nih.gov/39878633/

https://journals.lww.com/pain/abstract/9900/the_comparative_effectiveness_of_medicinal.807.aspx

Nav1.8, an analgesic target for nonpsychotomimetic phytocannabinoids

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“Pain impacts billions of people worldwide, but treatment options are limited and have a spectrum of adverse effects. The search for safe and nonaddictive pain treatments has led to a focus on key mediators of nociceptor excitability.

Voltage-gated sodium (Nav) channels in the peripheral nervous system-Nav1.7, Nav1.8, and Nav1.9-play crucial roles in pain signaling. Among these, Nav1.8 has shown promise due to its rapid recovery from inactivation and role in repetitive firing, with recent clinical studies providing proof-of-principal that block of Nav1.8 can reduce pain in humans.

We report here that three nonpsychotomimetic cannabinoids-cannabidiol (CBD), cannabigerol (CBG), and cannabinol (CBN)-effectively inhibit Nav1.8, suggesting their potential as analgesic compounds.

In particular, CBG shows significant promise due to its ability to effectively inhibit excitability of peripheral sensory neurons. These findings highlight the therapeutic potential of cannabinoids, particularly CBG, as agents that may attenuate pain via block of Nav1.8, warranting further in vivo studies.”

https://pubmed.ncbi.nlm.nih.gov/39835903/

“Chronic pain is a major health problem worldwide; however, treatment options remain limited and often involve adverse side-effects or addiction risk. Targeting voltage-gated sodium (Nav) channels in sensory neurons, particularly Nav1.8, represents a promising therapeutic approach. Our work demonstrates that nonpsychotomimetic cannabinoids, including cannabidiol (CBD), cannabigerol (CBG), and cannabinol (CBN), effectively inhibit Nav1.8. CBG, in particular, exhibits a potent inhibition of dorsal root ganglion neuron excitability, suggesting its potential as a nonaddictive analgesic. Our findings open different avenues for the development of cannabinoid-based treatments for pain therapy, with a focus on Nav1.8 inhibition as a therapeutic target.”

https://www.pnas.org/doi/10.1073/pnas.2416886122

[Impact of dronabinol shortage on a population of chronic pain patients: A retrospective observational study]

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“Objective: A supply shortage of dronabinol occurred between December 2023 and February 2024, forcing chronic pain patients to discontinue this treatment. We assessed the impact of this shortage on patients in our hospital.

Method: A retrospective observational study of patients treated with dronabinol was conducted. Collected data included socio-demographic, pharmacological and clinical data. Pain intensity and its interference, the intensity of other pain dimensions (mood, relationship with others, etc.) and quality of sleep were collected before discontinuation (dronabinol dosage balanced, M0) and at the end of discontinuation (dronabinol stopped for several weeks, M3). The patient’s perception of his state of health evolution was collected at the end of the shortage.

Results: Health deterioration was reported by 86% of patients after 3 months of rupture. Pain intensity and its interference with patients’ daily lives increased significantly. Patients’ sleep deteriorated significantly. The number of patients with permanent pain increased 5-fold (n=2 at M0 and n=10 at M3). The number of patients with more than 20 painful attacks per 24hours increased 2-fold (n=2 at M0 and n=4 at M3).

Conclusion: Although data on the efficiency of dronabinol are currently limited, this supply disruption has had negative clinical consequences for our patients. With drug shortages multiplying in recent years, the marketing of new specialties and therefore the availability of therapeutic alternatives could help reduce the clinical impact of a possible new dronabinol shortage in these refractory chronic pain patients.”

https://pubmed.ncbi.nlm.nih.gov/39824703/

https://www.sciencedirect.com/science/article/abs/pii/S0040595724002191?via%3Dihub

“Dronabinol has preferential antileukemic activity in acute lymphoblastic and myeloid leukemia with lymphoid differentiation patterns”

https://pubmed.ncbi.nlm.nih.gov/26775260/

Emerging trends in cannabis administration for women with chronic pain

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“Cannabis use among women who experience chronic pain is on the rise in the United States. However, little is known about women’s motives and preferences for cannabis administration. The purpose of this study was to characterize cannabis use among women with chronic pain.

This study examined self-reported forms of cannabis administration and preferred source of cannabis, frequency and quantity of use, and self-reported side effects, and type, level, and intensity of chronic pain among adult women in the United States. This study also compared women who use cannabis for chronic pain and those who do not across the level of chronic pain, length of chronic pain, and the number of types of chronic pain experienced.

Participants showed a significant preference (60%) for using recreational cannabis to treat chronic pain but reported that medical cannabis was more effective. For participants who preferred medical cannabis 24.3% reported daily use, as compared to only 7.8% of recreational cannabis users. Smoking was the most common form of administration (62.1%), followed by edibles (25.3%), vaporizing in any form (7.4%), tinctures and concentrates (3.2%), and topicals (2.1%). Participants reported using 1-6 different forms of cannabis administration. Those who preferred smoking were significantly likely to use all other forms of administration. However, those who preferred alternatives to smoking were significantly likely to use all forms of administration except for smoking. Medical cannabis users preferred to obtain cannabis from a dispensary, while recreational users preferred to obtain cannabis from unlicensed sources.

Additionally, participants who used cannabis for chronic pain reported a 74% reduction in past 30-day opioid use.

Future research is needed to investigate the health effects associated with single and combined forms of cannabis administration for women with chronic pain. Results can inform educational and intervention programs, treatment development, content regulation of products, policy formation, women’s health research, and public health guidelines.”

https://pubmed.ncbi.nlm.nih.gov/39816373/

https://onlinelibrary.wiley.com/doi/10.1002/mhs2.88