Cannabidiol as a Treatment for Chronic Pain: A Survey of Patients' Perspectives and Attitudes

Differences in Cannabidiol-Related Attitudes and Practice Behaviors Between U.S. Primary Care Physicians Practicing in a Single Health Care System Across States With and Without Marijuana Legalization

Introduction: Dramatic shifts in marijuana laws, along with federal deregulation of hemp with the 2018 Farm Bill, have resulted in increased availability and use of cannabidiol (CBD) supplements throughout the United States (US). Given the rapid increase in CBD use in the U.S. general population, in this study, we aim to characterize primary care physician (PCP) attitudes and practice behaviors and to assess whether differences in provider attitudes and behaviors vary as a function of marijuana legalization (ML) status in the state of practice. Materials and Methods: Data are from an online provider survey on CBD supplement-related attitudes, beliefs, and behaviors administered to 508 PCPs as part of a larger mixed methods study. Participating PCPs were recruited from the Mayo Clinic Healthcare Network and provided medical care in primary care settings across four U.S. states (Minnesota, Wisconsin, Florida, and Arizona). Results: The survey response rate was 45.4% (n=236/508). According to providers, CBD was frequently brought up in PCP settings, typically by patients. PCPs were generally hesitant to screen for or discuss CBD with their patients and identified multiple barriers to open patient-provider dialogue about CBD. PCPs practicing in states that had passed ML were more receptive to patients using CBD supplements, whereas PCPs practicing in states that had not passed ML were more concerned about CBD-related side effects. Regardless of state ML status, most PCPs did not feel that they should be recommending CBD supplements to their patients. Most PCPs reported believing that CBD was unhelpful for most conditions for which it is marketed, with chronic non-cancer pain and anxiety/stress being exceptions. PCP respondents generally felt that they had insufficient knowledge/training around CBD. Conclusions: Results from this mixed methods study show that PCPs practicing in the U.S. rarely screen for or discuss CBD use with their patients and report several barriers to engage in proactive CBD-focused practice behaviors. Furthermore, survey results show that some PCP attitudes, practice behaviors, and barriers vary as a function of state ML status. These findings may guide medical education efforts and inform primary care practice modifications aimed at enhancing screening and monitoring of patient CBD use by PCPs.

Cannabis use in Parkinson's disease: Patient access to medical cannabis and physician perspective on product safety

The rate of medical cannabis use has increased in parallel with the number of states legalizing its use. Parkinson's disease (PD) patients are of particular concern due to their higher cannabis use rate than in the general US population (25-40 % PD patient cannabis users vs. ∼18 % in the general population), as well as their susceptibility to environmental contaminants in cannabis, including pesticides, toxic elements, solvents, microbes, and mycotoxins. In order to address the complex nature of this industry, we examined the changes in PD-related qualifying conditions in the U.S. from 2019 to 2023. We also conducted an online survey to gain insight into the knowledge, risk perceptions, and opinions regarding medical cannabis and contamination issues from physicians who treated PD patients. The number of states including PD-related qualifying conditions increased over the past 5 years from 28 to 36 states. These conditions included PD (increasing from 14 to 16 states), muscle spasms (14 to 24), anxiety (1 to 5), and pain (17 to 35). State-by-state comparisons revealed high variability in the language used to describe the different qualifying conditions. Online surveys were sent out to 45 neurologists and movement disorder specialists who primarily treated PD patients. The response rate was 44 % from nine states (AZ, CA, FL, MA, MN, WI, PA, IL, and NM). When asked if they were aware of any contaminants in cannabis products, we found that 65 % of the physicians were unaware of any contaminants commonly found in cannabis and only 25 %, 15 %, and 15 % of them were aware of pesticide, toxic element, and solvent contaminants, respectively. In their free-text opinion response on the health impact of cannabis-borne contaminants, "long-term effect" (35 %) and "comorbidities and PD prognosis" (40 %) were identified as the two most common themes. These results point to the need for further regulatory deliberation regarding risks and susceptibility to cannabis contaminants. Additionally, education is needed to inform physicians on cannabis safety issues. Further research will identify the implementation strategies to reduce contaminant exposure and protect patient health.

Perceptions and engagement of patients with chronic conditions on the use of medical cannabis: a scoping review

CONTEXT

Studies generally focus on one type of chronic condition and the effect of medical cannabis (MC) on symptoms; little is known about the perceptions and engagement of patients living with chronic conditions regarding the use of MC.

OBJECTIVES

This scoping review aims to explore: (1) what are the dimensions addressed in studies on MC that deal with patients' perceptions of MC? and (2) how have patients been engaged in developing these studies and their methodologies? Through these objectives, we have identified areas for improving future research.

METHODS

We searched five databases and applied exclusion criteria to select relevant articles. A thematic analysis approach was used to identify the main themes: (1) reasons to use, to stop using or not to use MC, (2) effects of MC on patients themselves and empowerment, (3) perspective and knowledge about MC, and (4) discussion with relatives and healthcare professionals.

RESULTS

Of 53 articles, the main interest when assessing the perceptions of MC is to identify the reasons to use MC (n = 39), while few articles focused on the reasons leading to stop using MC (n = 13). The majority (85%) appraise the effects of MC as perceived by patients. Less than one third assessed patients' sense of empowerment. Articles determining the beliefs surrounding and knowledge of MC (n = 41) generally addressed the concerns about or the comfort level with respect to using MC. Only six articles assessed patients' stereotypes regarding cannabis. Concerns about stigma constituted the main topic while assessing relationships with relatives. Some articles included patients in the research, but none of them had co-created the data collection tool with patients.

CONCLUSIONS

Our review outlined that few studies considered chronic diseases as a whole and that few patients are involved in the co-construction of data collection tools as well. There is an evidence gap concerning the results in terms of methodological quality when engaging patients in their design. Future research should evaluate why cannabis' effectiveness varies between patients, and how access affects the decision to use or not to use MC, particularly regarding the relationship between patients and healthcare providers. Future research should consider age and gender while assessing perceptions and should take into consideration the legislation status of cannabis as these factors could in fact shape perception. To reduce stigma and stereotypes about MC users, better quality and accessible information on MC should be disseminated.

Cannabidiol and brain function: current knowledge and future perspectives

Cannabidiol (CBD) is a naturally occurring non-psychoactive cannabinoid found in Cannabis sativa, commonly known as cannabis or hemp. Although currently available CBD products do not meet the safety standards of most food safety authorities to be approved as a dietary supplement or food additive, CBD has been gaining widespread attention in recent years due to its various potential health benefits. While primarily known for its therapeutic effects in managing epileptic seizures, psychosis, anxiety, (neuropathic) pain, and inflammation, CBD's influence on brain function has also piqued the interest of researchers and individuals seeking to enhance cognitive performance. The primary objective of this review is to gather, synthesize, and consolidate scientifically proven evidence on the impact of CBD on brain function and its therapeutic significance in treating neurological and mental disorders. First, basic background information on CBD, including its biomolecular properties and mechanisms of action is presented. Next, evidence for CBD effects in the human brain is provided followed by a discussion on the potential implications of CBD as a neurotherapeutic agent. The potential effectiveness of CBD in reducing chronic pain is considered but also in reducing the symptoms of various brain disorders such as epilepsy, Alzheimer's, Huntington's and Parkinson's disease. Additionally, the implications of using CBD to manage psychiatric conditions such as psychosis, anxiety and fear, depression, and substance use disorders are explored. An overview of the beneficial effects of CBD on aspects of human behavior, such as sleep, motor control, cognition and memory, is then provided. As CBD products remain largely unregulated, it is crucial to address the ethical concerns associated with their use, including product quality, consistency, and safety. Therefore, this review discusses the need for responsible research and regulation of CBD to ensure its safety and efficacy as a therapeutic agent for brain disorders or to stimulate behavioral and cognitive abilities of healthy individuals.

Knowledge and Attitudes of Cannabidiol in Croatia among Students, Physicians, and Pharmacists

Due to cannabidiol's health benefits and absence of serious side effects, its use is constantly growing. This is a survey-based cross-sectional study that was conducted to determine Croatian pharmacists', physicians', and students' knowledge and attitudes about cannabidiol (CBD). Two questionnaires were created, one for students and the other for physicians and pharmacists. Our participants (in total 874: 473 students and 401 physicians and pharmacists) generally had positive attitudes towards CBD therapy as approximately 60% of them believe that CBD treatment is generally efficacious. Participants had positive attitudes toward the therapeutic value of CBD, especially pharmacists and pharmacy students (63.8% and 72.2%, respectively). Pharmacists were significantly more convinced that CBD could reduce the use of opioids prescribed for chronic pain (p < 0.05). Only 17.5% of students had read scientific papers about CBD, compared to a significantly higher percentage of physicians and pharmacists (43.0% and 47.8%, respectively) (p < 0.05). This study revealed a gap in knowledge regarding CBD, since 89.3% of pharmacists and physicians, as well as 84.8% of students, believe they need more education about CBD. We conclude that it is important to improve the educational curricula so that medical professionals can recommend CBD use to their patients when needed.

A Continuing Pharmacy Education (CPE) Program Assessing Cannabidiol (CBD) Knowledge and Confidence Among Practicing Pharmacists

Background: Increased patient utilization of cannabidiol (CBD) leads to potential drug interactions with various medications and questions posed to pharmacists. Objective: To quantify the knowledge gap of pharmacists on CBD and CBD-containing products and assess the degree a continuing pharmacy education (CPE) program alters pharmacist confidence and competency on CBD knowledge. Methods: A 1-h CPE activity was offered as a home study from May 9, 2022, through September 30, 2022. Subjects were practicing pharmacy preceptors in Alabama who completed the pre-survey and post-survey for inclusion in matched-pair analyses. The primary outcome measure was participant score improvement between the pre-post surveys. Secondary measures involved pre-post comparisons on self-rated Likert questions concerning participant confidence in counseling, answering drug information questions, and ensuring patient safety regarding CBD. Results: A total of 124 participants completed the course. After matched pairing, 64 and 56 individuals were included in the knowledge-based and confidence ranking analyses, respectively. Participant scoring improved on the knowledge-based questions between the pre-post surveys (50.0% vs 87.8%, P < .001). There was a significant confidence improvement of participants from baseline on counseling patients about prescription or over-the-counter CBD products, answering questions from other healthcare professionals about these products, and ensuring patient safety while using these products (Average 5-level Likert scale increases of 1.75, 1.73, 1.70, respectively; all P < .001). Conclusion: Implementation of a CPE program improved practicing pharmacists' knowledge on information about CBD, which lead to increased competency on counseling patients, answering drug information questions, and promoting patient safety.

Experiences and Perceptions of Medical Cannabis among People Living with Chronic Pain and Community Pharmacists: A Qualitative Study in Canada

Background

The use of cannabis to treat chronic pain is under debate despite high expectations from patients. Qualitative data obtained by exploring both patients' and health professionals' perspectives are scarce.

Aims

This study aimed to understand the experiences and perceptions of people living with chronic pain and community pharmacists regarding the role of cannabis in chronic pain treatment in the Canadian context where both medical and recreational cannabis are legal.

Methods

We conducted 12 online focus groups (July 2020-February 2021) with 26 patients and 19 community pharmacists using semistructured discussion guides. All discussions were audio recorded and transcribed verbatim were analyzed using a reflexive thematic approach.

Results

We developed three themes related to patients' perspectives and three themes related to pharmacists' perspectives. Patients' perspectives included (1) cannabis as an alternative to other pain medications, (2) a new treatment with potential health-related risks, and (3) a therapy rather than a recreational drug. Pharmacists' perspectives included (1) challenges in monitoring drug interactions with cannabis in the context of scarce research data, (2) informing and treating patients self-medicating with cannabis amid its growing popularity, and (3) financial costs and legal constraints for patients.

Conclusions

This study highlights patients' and pharmacists' urgent need for reliable information regarding the benefits and risks of cannabis. Training tailored to pharmacists' needs and evidence-based information for patients should be developed to support pharmacists' practice, improve patients' experiences, and promote safe cannabis use.

Pain Medications Used by Persons Living With Fibromyalgia: A Comparison Between the Profile of a Quebec Sample and Clinical Practice Guidelines

Background

Pharmacological management of fibromyalgia is complex. Chronic pain management is characterized by off-label prescribing and use, multimorbidity, and polypharmacy.

Aims

This study aimed to describe pain medications use and perceived risk among people living with fibromyalgia and compare this use to evidence-based recommendations.

Methods

Directive telephone interviews were conducted with 63 individuals self-reporting a diagnosis of fibromyalgia (Quebec, Canada). The questionnaire addressed specific questions about their pain and pharmacological treatments currently used for pain management (prescribed and over-the-counter). Collected data were compared to the Canadian Fibromyalgia Clinical Practice Guidelines and to evidence reports published by recognized organizations.

Results

Despite a lack of robust scientific evidence to support opioids use to manage pain in fibromyalgia, 33% of our sample reported using them. Nonsteroidal anti-inflammatory drugs were used by 54.0% of participants, although this medication is not recommended due to lack of efficacy. Tramadol, which is recommended, was used by 23.8% of participants. Among the medications strongly recommended, anticonvulsants were used by 36.5%, serotonin norepinephrine reuptake inhibitor antidepressants by 55.6%, and tricyclic antidepressants by 22.2%. Cannabinoids (17.5%) and medical cannabis (34.9%) use were also reported. For all of these medication subclasses, no differences were found between participants not reporting (n = 35) or reporting (n = 28) more than one pain diagnosis (P < 0.05). Medication subclasses considered most at risk of adverse effects by participants were the least used.

Conclusions

Results reveal discordance between evidence-based recommendations and medications use, which highlights the complexity of pharmacological treatment of fibromyalgia.

Cannabis for the Treatment of Fibromyalgia: A Systematic Review

Fibromyalgia is a common disease syndrome characterized by chronic pain and fatigue in conjunction with cognitive dysfunction such as memory difficulties. Patients currently face a difficult prognosis with limited treatment options and a diminished quality of life. Given its widespread use and potential efficacy in treating other types of pain, cannabis may prove to be an effective treatment for fibromyalgia. This review aims to examine and discuss current clinical evidence regarding the use of cannabis for the treatment of fibromyalgia. An electronic search was conducted on MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus using Medical Subject Heading (MeSH) terms on all literature published up to October 2022. A follow-up manual search included a complete verification of relevant studies. The results of four randomized controlled trials (RCTs) and five observational studies (a total of 564 patients) that investigated the effects of cannabis on fibromyalgia symptoms were included in this review. Of the RCTs, only one demonstrated that cannabinoids did not have a different effect than placebo on pain responses. Overall, this analysis shows low-quality evidence supporting short-term pain reduction in people with fibromyalgia treated with cannabinoid therapeutics. Although current evidence is limited, medical cannabis appears to be a safe alternative for treating fibromyalgia.

Medical Cannabis for Chronic Nonmalignant Pain Management

PURPOSE OF REVIEW

Cannabis has been used since ancient times for medical and recreational research. This review article will document the validity of how medical cannabis can be utilized for chronic nonmalignant pain management.

RECENT FINDINGS

Current cannabis research has shown that medical cannabis is indicated for symptom management for many conditions not limited to cancer, chronic pain, headaches, migraines, and psychological disorders (anxiety and post-traumatic stress disorder). Δ9-Tetrahydrocannabinol (THC) and cannabidiol (CBD) are active ingredients in cannabis that modulate a patient's symptoms. These compounds work to decrease nociception and symptom frequency via the endocannabinoid system. Research regarding pain management is limited within the USA as the Drug Enforcement Agency (DEA) classifies it as a schedule one drug. Few studies have found a limited relationship between chronic pain and medical cannabis use. A total of 77 articles were selected after a thorough screening process using PubMed and Google Scholar. This paper demonstrates that medical cannabis use provides adequate pain management. Patients suffering from chronic nonmalignant pain may benefit from medical cannabis due to its convenience and efficacy.

Transient Receptor Potential (TRP) Channels in Pain, Neuropsychiatric Disorders, and Epilepsy

Pharmacomodulation of membrane channels is an essential topic in the study of physiological conditions and disease status. Transient receptor potential (TRP) channels are one such family of nonselective cation channels that have an important influence. In mammals, TRP channels consist of seven subfamilies with a total of twenty-eight members. Evidence shows that TRP channels mediate cation transduction in neuronal signaling, but the full implication and potential therapeutic applications of this are not entirely clear. In this review, we aim to highlight several TRP channels which have been shown to mediate pain sensation, neuropsychiatric disorders, and epilepsy. Recent findings suggest that TRPM (melastatin), TRPV (vanilloid), and TRPC (canonical) are of particular relevance to these phenomena. The research reviewed in this paper validates these TRP channels as potential targets of future clinical treatment and offers patients hope for more effective care.

Long-Term, Self-Dosing CBD Users: Indications, Dosage, and Self-Perceptions on General Health/Symptoms and Drug Use

Introduction

Self-dosing of off-the-shelf cannabidiol (CBD) for a myriad of health conditions is common in the USA. These CBD products are often mislabeled, suggesting that much less or much more CBD is being consumed than indicated on the label. This study examined the relationship between long-term self-dosing of CBD and (a) indications and, when a verified concentration of CBD is being consumed, (b) the daily CBD dosage, (c) the impact on general health and symptoms, and (d) over-the-counter (OTC) and prescription (Rx) drug usage.

Methods

US adults 18-75 years of age who had used unverified CBD products for >1 month were recruited to participate in this decentralized, observational, IRB-approved study and provided a concentration-verified CBD product of their choice from 15 different vendors for 4 weeks. Prior to receiving product, they were queried on their primary reason for use (PRfU), primary symptom for use (PSfU), general health score (GHS), symptom score (SS), OTC and Rx drug use, and daily CBD dose. Individuals were queried daily on OTC and Rx drug use and CBD dose and weekly on SS and GHS prior to (pre-CBD) and after (post-CBD) ingestion of CBD on that day.

Results

The PRfU included chronic pain, mental health, general health and wellness, sleep disorders, the central nervous system, digestive health, and others, while the PSfU included anxiety, back and/or joint pain, sleep, inflammation, and others. The mean daily dose was normally distributed, with a mean, median, and range of 53.1, 40.8, 8-390 mg/day, respectively. For both GHS and SS, the post-CBD was significantly higher than the pre-CBD score for each category of PRfU. The GHS scores did not change over the study, but pre- and post-CBD SS improved over time, with pre-improving more than post-CBD SS. The percentage of individuals decreasing or completely stopping OTC drugs or Rx drugs over the 4 weeks was 31.2% and 19.2%, respectively, with those taking CBD for chronic pain, decreasing drug use the most. OTC and Rx drug usage decreased when the CBD dose was changed and when GHS and SS improved.

Conclusion

Pain, mental health (primarily anxiety/stress), and sleep are the most common reasons for CBD use. Self-administration of CBD reduced OTC and Rx drug usage at daily doses less than those reported in controlled studies. CBD self-administration significantly improves self-perception of general health and decreases symptom severity, and as these improve, fewer OTC and Rx drugs are used.

Primary care provider attitudes, experiences and practices about cannabidiol (CBD) and barriers to patient-provider communication about CBD use: A qualitative study

Objectives

Federal hemp legalization and ongoing shifts in US marijuana laws have led to increased population-wide use of cannabidiol (CBD) supplements, often without the knowledge of primary healthcare providers (PCPs). Given the potential risks related to CBD use, especially in vulnerable subgroups, improved communication is warranted. This study aimed to examine PCP attitudes, experiences, and practice behaviors related to CBD and provider-reported barriers to communication with patients about CBD use.

Methods

Fourteen PCPs were recruited and participated in semi-structured interviews. Transcripts were digitally analyzed using inductive thematic analysis.

Results

Analyses identified that most PCPs had neutral views about CBD use by their patients. The study found that discussions about CBD use were initiated by patients. Most PCPs cited lack of time, discomfort, low-quality evidence, and low prioritization as reasons for not discussing CBD with patients.

Conclusion

PCPs rarely screen for or discuss CBD use with their patients and most of them had neutral views about CBD use by their patients. A number of barriers exist to open dialogue about CBD.

Innovation

Our study is the first in-depth report on PCP attitudes, experiences, and practice behaviors related to CBD. The findings of our study have the potential to significantly impact future PCP practice behaviors. These results can inform healthcare system policies around screening for CBD use and PCP communication training. In doing so, these efforts may mitigate risk and optimize benefits related to the expanding CBD market.

Cannabidiol as a treatment for arthritis and joint pain: an exploratory cross-sectional study

Introduction

An estimated 54 million Americans currently suffer from debilitating arthritis. Patients who have exhausted conservative measures can be subject to chronic pain and resort to symptomatic management with anti-inflammatories, acetaminophen, and opioids. Cannabidiol (CBD) is a non-psychoactive cannabinoid that has shown promise in preclinical studies to reduce inflammation and pain associated with arthritis. The purpose of this study was to explore patient perceived effects of cannabidiol on symptoms of arthritis.

Methods

A novel anonymous questionnaire was created to evaluate perceived efficacy of cannabidiol for the treatment of arthritis. A self-selected convenience sample (N=428) was recruited through online methods including social media accounts and newsletters (The Arthritis Foundation and Savvy Cooperative) between May 5, 2020, and November 5, 2020. Statistical analysis was performed to determine differences between types of arthritis and improvements in quality-of-life symptoms. Furthermore, a regression analysis was performed to identify variables associated with decreasing or discontinuing other medications.

Results

CBD use was associated with improvements in pain (83%), physical function (66%), and sleep quality (66%). Subgroup analysis by diagnosis type (osteoarthritis, rheumatoid, or other autoimmune arthritis) found improvements among groups for physical function (P=0.013), favoring the osteoarthritis group. The overall cohort reported a 44% reduction in pain after CBD use (P<0.001). The osteoarthritis group had a greater percentage reduction (P=0.020) and point reduction (P<0.001) in pain compared to rheumatoid arthritis and other autoimmune arthritis. The majority of respondents reported a reduction or cessation of other medications after CBD use (N=259, 60.5%): reductions in anti-inflammatories (N=129, 31.1%), acetaminophen (N=78, 18.2%), opioids (N=36, 8.6%) and discontinuation of anti-inflammatories (N=76, 17.8%), acetaminophen (N=76, 17.8%), and opioids (N=81, 18.9%).

Conclusion

Clinicians and patients should be aware of the various alternative therapeutic options available to treat their symptoms of arthritis, especially in light of the increased accessibility to cannabidiol products. The present study found associations between CBD use and improvements in patient’s arthritis symptoms and reductions in other medications. Future research should focus on exploring the benefits of CBD use in this patient population with clinical trials.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42238-022-00154-9.

TRP channels: a journey towards a molecular understanding of pain

The perception of nociceptive signals, which are translated into pain, plays a fundamental role in the survival of organisms. Because pain is linked to a negative sensation, animals learn to avoid noxious signals. These signals are detected by receptors, which include some members of the transient receptor potential (TRP) family of ion channels that act as transducers of exogenous and endogenous noxious cues. These proteins have been in the focus of the field of physiology for several years, and much knowledge of how they regulate the function of the cell types and organs where they are expressed has been acquired. The last decade has been especially exciting because the 'resolution revolution' has allowed us to learn the molecular intimacies of TRP channels using cryogenic electron microscopy. These findings, in combination with functional studies, have provided insights into the role played by these channels in the generation and maintenance of pain.

Prevalence of cannabis use for pain management in Quebec: A post-legalization estimate among generations living with chronic pain

Background

Medical cannabis has been legal in Canada since 2001, and recreational cannabis was legalized in October 2018, which has led to a widespread increase in the accessibility of cannabis products.

Aims

This study aimed to estimate the prevalence of cannabis use among adults living with chronic pain (CP) and investigate the relationship between age and cannabis use for CP management.

Methods

A cross-sectional analysis of the COPE Cohort data set, a large Quebec sample of 1935 adults living with CP, was conducted. Participants completed a web-based questionnaire in 2019 that contained three yes/no questions about past-year use of cannabis (i.e., for pain management, management of other health-related conditions, recreational purposes).

Results

Among the 1344 participants who completed the cannabis use section of the questionnaire, the overall prevalence of cannabis use for pain management was 30.1% (95% confidence interval 27.7-32.7). Differences were found between age groups, with the highest prevalence among participants aged ≤26 years (36.5%) and lowest for those aged ≥74 years (8.8%). A multivariable logistic model revealed that age, region of residence, generalized pain, use of medications or nonpharmacological approaches for pain management, alcohol/drug consumption, and smoking were associated with the likelihood of using cannabis for pain management.

Conclusions

Cannabis is a common treatment for the management of CP, especially in younger generations. The high prevalence of use emphasizes the importance of better knowledge translation for people living with CP, rapidly generating evidence regarding the safety and efficacy of cannabis, and clinicians' involvement in supporting people who use cannabis for pain management.

Medical Cannabis for Gynecologic Pain Conditions: A Systematic Review

OBJECTIVE

The endocannabinoid system is involved in pain perception and inflammation. Cannabis contains delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), which are cannabinoids that bind to endocannabinoid system receptors. A fatty acid amide called palmitoylethanolamide (PEA) enhances endogenous cannabinoids. Given that use of medical cannabis is increasing, we sought to characterize patterns of cannabis use for gynecologic pain and its effectiveness as an analgesic.

DATA SOURCES

We searched PubMed, EMBASE, Scopus, Cochrane, and ClinicalTrials.gov using terms for "woman," "cannabis," and "pain" or "pelvic pain" or "endometriosis" or "bladder pain" or "cancer." The search was restricted to English-language articles published between January 1990 and April 2021 and excluded animal studies.

METHODS OF STUDY SELECTION

The initial search yielded 5,189 articles with 3,822 unique citations. Studies were included if they evaluated nonpregnant adult women who used cannabinoids for gynecologic pain conditions (eg, chronic pelvic pain, vulvodynia, endometriosis, interstitial cystitis, malignancy). Study types included were randomized controlled trials (RCTs), cohort studies, and cross-sectional studies. Covidence systematic review software was used.

TABULATION, INTEGRATION, AND RESULTS

Fifty-nine studies were considered for full review, and 16 met inclusion criteria. Prevalence of cannabis use ranged from 13% to 27%. Most women ingested or inhaled cannabis and used cannabis multiple times per week, with dosages of THC and CBD up to 70 mg and 2,000 mg, respectively. Sixty-one to 95.5% reported pain relief. All six prospective cohort studies and one RCT of PEA-combination medications reported significant pain relief, and the average decrease in pain after 3 months of treatment was 3.35±1.39 on the 10-point visual analog scale. However, one fatty acid amide enzyme inhibitor RCT did not show pain reduction.

CONCLUSION

Survey data showed that most women reported that cannabis improved pain from numerous gynecologic conditions. Cohort studies and an RCT using PEA-combination medications reported pain reduction. However, interpretation of the studies is limited due to varying cannabis formulations, delivery methods, and dosages that preclude a definitive statement about cannabis for gynecologic pain relief.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42021248057.