Therapeutic potential of cannabinoids in neurological conditions: a systematic review of clinical trials

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“Overview: Cannabinoids have gained increasing attention for their therapeutic potential in treating several neurological conditions, including neurodegenerative diseases, chronic pain, and epilepsy. This review aims to assess the current clinical trials investigating cannabinoids, primarily Tetrahydrocannabinol and Cannabidiol, for neurological disorders. This review will aim to highlight the efficacy, safety, and outcome measures used in these trials.

Methods: Clinical trials were identified using ClinicalTrials.gov, focusing on studies that examined the effects of cannabinoids in treating neurological conditions. All trials that fulfilled the following criteria were included: Phase 1-4, focused on cannabinoids as primary intervention, and measured relevant outcomes such as pain relief, cognitive function, or spasticity reduction. Data on conditions, interventions, primary and secondary outcomes, and trial phases were extracted and analysed.

Results: A total of 47 clinical trials were identified, including different neurological conditions. The most frequently studied conditions were Multiple Sclerosis, Fibromyalgia, and Parkinson’s Disease. Most trials were in Phase 2, with the primary outcome measures focused on pain management, spasticity, and cognitive function. Secondary outcomes included safety and tolerability measures.

Conclusion: The review highlights the broad therapeutic potential of cannabinoids in neurology, with promising results in symptom management for conditions like Multiple Sclerosis and Fibromyalgia. However, the lack of standardized study protocols, dosing, and outcome measures presents challenges for broader clinical implementation.”

https://pubmed.ncbi.nlm.nih.gov/39981181/

“The results of this analysis showed that both CBD and THC have significant potential as therapeutic agents for neurological disorders, particularly in managing pain, motor dysfunction, and behavioural disturbances. However, their different pharmacological profiles and side effect risks mean that each cannabinoid may be better suited to different patient populations and conditions. While THC’s broader range of applications in cognitive and motor symptoms positions it as a more multipurpose treatment option, the psychoactive risks associated with its use should not be ignored. On the other hand, CBD’s safety and non-psychoactive nature make it more preferred option for managing chronic pain, but its therapeutic benefits may be more limited. Future research should focus on addressing the gaps in long-term safety and efficacy data, as well as exploring the full potential of lesser-known cannabinoids and combination therapies to further enhance the treatment of neurological disorders.”

https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2025.1521792/full

Medical Cannabis for Patients Over Age 50: A Multi-site, Prospective Study of Patterns of Use and Health Outcomes

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“Objective: Cannabis is being used as a therapeutic option by patients around the globe, and older patients represent a rapidly growing subset of this population. This study aims to assess the patterns of medical cannabis use in patients over 50 years of age and its effect on health outcomes such as pain, sleep, quality of life, and co-medication.

Method: The Medical Cannabis in Older Patients Study (MCOPS) is a multi-site, prospective observational study examining the real-world impact of medical cannabis use on patients over age 50 under the guidance of a health care provider. The study included validated instruments, with treating physicians collecting detailed data on participant characteristics, medical cannabis and co-medication use, and associated impacts on pain, sleep, quality of life, as well as adverse events.

Results: Inclusion criteria were met by 299 participants. Average age of participants was 66.7 years, and 66.2% of respondents identified as female. Approximately 90% of patients used medical cannabis to treat pain-related conditions such as chronic pain and arthritis. Almost all patients reported a preference for oral cannabis products (e.g., extracts, edibles) rather than inhalation products (e.g., flower, vapes), and most preferred oral formulations high in cannabidiol and low in tetrahydrocannabinol.

Over the six-month study period, significant improvements were noted in pain, sleep, and quality of life measures, with 45% experiencing a clinically meaningful improvement in pain interference and in sleep quality scores. Additionally, nearly 50% of patients taking co-medications at baseline had reduced their use by the end of the study period, and quality of life improved significantly from baseline to M3 and from baseline to M6, with an incremental cost per quality-adjusted life-year (QALY) of $25,357.20. No serious adverse events (SAEs) were reported.

Conclusions: In this cohort of older patients, most of whom suffered from pain-related conditions, medical cannabis seemed to be a safe and effective treatment. Most patients experienced clinically significant improvements in pain, sleep, and quality of life and reductions in co-medication. The cost per QALY was well below the standard for traditional pharmaceuticals, and no SAEs were reported, suggesting that cannabis is a relatively safe and cost-effective therapeutic option for adults dealing with age-related health conditions.”

https://pubmed.ncbi.nlm.nih.gov/39968489/

https://publications.sciences.ucf.edu/cannabis/index.php/Cannabis/article/view/239

Recreational Cannabis Laws and Fills of Pain Prescriptions in the Privately Insured

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“Objective: Almost half of U.S. states have passed recreational cannabis laws as of May 2024. While considerable evidence to date indicates cannabis may be a substitute for prescription opioids in the treatment of pain, it remains unclear if patients are treating pain with cannabis alone or concomitantly with other medications.

Method: Using data from a national sample of commercially insured adults, we examine the effect of recreational cannabis legalization (through two sequential policies) on prescribing of opioids, NSAIDS, and other pain medications by implementing synthetic control estimations and constructing case-study level counterfactuals for the years 2007-2020.

Results: Overall, we find recreational cannabis legalization is associated with a decrease in opioid fills among commercially insured adults in the U.S., and we find evidence of a compositional change in prescriptions of pain medications more broadly. Specifically, we find marginally significant increases in prescribing of non-opioid pain medications after recreational cannabis becomes legal in some states. Once recreational cannabis dispensaries open, we find statistically significant decreases in the rate of opioid prescriptions (13% reduction from baseline, p < .05) and marginally significant decreases in the average daily supply of opioids (6.3% decrease, p < .10) and number of opioid prescriptions per patient (3.5% decrease, p < .10).

Conclusions: These results suggest that substitution of cannabis for traditional pain medications increases as the availability of recreational cannabis increases. There appears to be a small shift once recreational cannabis becomes legal, but we see stronger results once users can purchase cannabis at recreational dispensaries. The decrease in opioids and marginal increase in non-opioid pain medication may reflect patients substituting opioids with cannabis and non-opioid pain medications, either separately or concomitantly. Reductions in opioid prescription fills stemming from recreational cannabis legalization may prevent exposure to opioids in patients with pain and lead to decreases in the number of new opioid users, rates of opioid use disorder, and related harms.”

https://pubmed.ncbi.nlm.nih.gov/39968486/

https://publications.sciences.ucf.edu/cannabis/index.php/Cannabis/article/view/268

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

Entourage effects of nonpsychotropic cannabinoids on visceral sensitivity in experimental colitis

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“Abdominal pain is the most disabling symptom of inflammatory bowel diseases, but current treatments are limited, leading patients to seek alternatives such as cannabis.

Cannabis contains over 100 cannabinoids which, unlike tetrahydrocannabinol, are biologically active compounds often without psychotropic effects (ie, nonpsychotropic cannabinoids [npCBs]). These npCBs have analgesic and anti-inflammatory properties and may show potentiating effects when administered in combination, referred to as the entourage effect.

Here, we investigated the analgesic effects of cannabichromene, cannabidiol (CBD), cannabidivarin, and cannabigerol (CBG), individually and in combination, using the mouse model of dextran sulfate sodium colitis-induced visceral hypersensitivity (VHS).

We then explored antinociceptive targets through patch-clamp electrophysiology on dorsal root ganglia neurons and recombinant channels. We found that a single injection of 10 mg/kg of either CBD or CBG reduced both VHS and c-Fos activation in the spinal dorsal horn. Moreover, a combination of npCBs consisting of 5 mg/kg CBD with 1 mg/kg of cannabichromene, cannabidivarin, and CBG-all at subtherapeutic dosages-reduced VHS, without altering colitis. Electrophysiological recordings revealed that the antinociceptive mixture of npCBs acts through voltage-gated sodium and calcium channels, particularly Cav2.2, but not Cav3.2 and Kv channels.

These results suggest that CBD, CBG, and a mixture of npCBs given at subtherapeutic doses may be beneficial in managing VHS associated with inflammatory bowel disease.

SIGNIFICANCE STATEMENT: Cannabis is increasingly used as an alternative treatment for managing pain associated with chronic conditions. Nonpsychotropic cannabinoids, such as cannabidiol, interact with ionotropic and voltage-gated ion channels. In our study, we demonstrated that cannabidiol, cannabigerol, and a combination of nonpsychotropic cannabinoids, administered at subtherapeutic doses, effectively alleviated visceral hypersensitivity associated with inflammatory bowel disease.”

https://pubmed.ncbi.nlm.nih.gov/39921943/

https://jpet.aspetjournals.org/article/S0022-3565(25)09725-3/abstract

UK Medical Cannabis Registry: An Analysis of Clinical Outcomes of Medicinal Cannabis Therapy for Cancer Pain

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“Cancer pain (CP) is a prevalent condition with limited pharmacotherapeutic options. Cannabis-based medicinal products (CBMPs) have shown analgesic effects, but their efficacy in CP remains contentious.

This study aims to evaluate the change in patient-reported outcome measures (PROMs) and adverse events (AEs) in CP patients treated with CBMPs.

A case series was conducted using prospectively collected clinical data from the UK Medical Cannabis Registry. Primary outcomes were the changes in the Brief Pain Inventory (BPI), pain visual analogue scale (Pain-VAS), EQ-5D-5L, Generalized Anxiety Disorder-7 (GAD-7), Patient Global Impression of Change (PGIC) and Single-Item Sleep Quality Scale (SQS) questionnaires from baseline to 1, 3, and 6 months. AEs were recorded and graded. p < 0.050 was considered statistically significant. One hundred and sixty-eight participants were included.

CBMPs were associated with improvements in all pain-specific PROMs at all follow-up periods (p < 0.050).

Improvements in GAD-7, SQS, and EQ-5D-5L index scores were also observed (p < 0.050). Twenty-nine AEs (17.26%) were reported by five patients (2.98%), mostly mild-to-moderate (72.41%). Although the observational design means causality cannot be established, the findings support the development of future randomized controlled trials into CP management with CBMPs.”

https://pubmed.ncbi.nlm.nih.gov/39921589/

“This study found that initiation of CBMPs is associated with improvements in pain-specific and general health-related quality of life outcomes in CP patients over six months, with a relatively low incidence of mild-to-moderate AEs and no life-threatening AEs.”

https://www.tandfonline.com/doi/full/10.1080/15360288.2025.2457101

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