Toxic Effects of Marijuana on the Cardiovascular System

Cannabis Use Disorder Associated With Increased Risk of Postoperative Complications After Hip or Knee Arthroplasties: A Meta-analysis of Observational Studies

INTRODUCTION

With the legalization of marijuana in the United States, the number of patients with cannabis use disorder (CUD) in the joint arthroplasty population has increased markedly. The primary purpose of this meta-analysis was to determine whether there were differences in clinical and economic outcomes after total joint arthroplasty (TJA) between patients with and without perioperative CUD.

METHODS

We searched PubMed, Embase, Scopus, and Web of Science databases up to July 2018 to identify all eligible studies investigating the association of CUD with postoperative outcomes in patients undergoing TJA. Postoperative outcomes assessed consisted of complications, readmission, length of stay (LOS), implant revision, and cost of care. For dichotomous outcomes, pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated using a random effects model.

RESULTS

We identified 10 retrospective cohort studies with a total of 17,981,628 study participants. Patients with CUD had significantly higher odds of medical complications (OR 1.33 [95% CI 1.07 to 1.66], P = 0.01) and implant-related complications (OR 1.75 [95% CI: 1.64 to 1.88], P < 0.00001) than noncannabis users. Specifically, CUD was associated with significantly increased odds of cardiac complications (OR 1.95 [95% CI 1.50 to 2.54], P < 0.00001), cerebrovascular accidents (OR 2.06 [95% CI 1.66 to 2.57], P < 0.00001), postoperative infections (OR 1.68 [95% CI 1.34 to 2.10], P < 0.00001), periprosthetic fracture (OR 1.42 [95% CI 1.19 to 1.70], P < 0.0001), mechanical loosening (OR 1.54 [95% CI 1.42 to 1.66], P < 0.00001), and dislocation/instability (OR 1.88 [95% CI 1.32 to 2.68], P = 0.0005). Longer LOS and higher cost of care were also found in patients with CUD.

CONCLUSION

This study strengthens the body of evidence that patients with CUD face higher risk of postoperative complications and greater financial burden after knee and hip arthroplasties. Physicians should inform patients about adverse outcomes and undertake appropriate risk adjustments before elective orthopaedic surgery.

LEVEL OF EVIDENCE

Level III.

Spontaneous Coronary Artery Dissection in the Setting of Marijuana: A Case Report

This case report presents a detailed examination of spontaneous coronary artery dissection (SCAD) in a 61-year-old Middle Eastern male with a history of marijuana use and essential hypertension. The patient's emergency presentation with loss of consciousness and subsequent diagnostics - including elevated troponins and distinctive electrocardiogram changes - led to the identification of extensive SCAD affecting multiple coronary arteries. The association between marijuana use and cardiovascular pathology is focal in this study, particularly considering the patient's positive test for tetrahydrocannabinol (THC) and significant smoking history. This case highlights the critical need for heightened awareness among clinicians regarding the implications of recreational marijuana use, particularly in individuals with predisposing cardiovascular risk factors. Furthermore, it illustrates the complexity of diagnosing and managing SCAD, a condition that may vary widely in its presentation and severity, necessitating a tailored approach to treatment that considers both the acute manifestations and underlying contributory factors such as substance use.

Bilateral Optic Neuropathy Associated with Acute Inhaled Marijuana Use: Case Report and Review of the Literature

Marijuana is the most commonly used federally illegal drug in the United States. Acute marijuana use is associated with several cardiovascular and neuropsychological adverse effects. Ocular complications of marijuana abuse are very rare. Herein, we present the first report of bilateral optic neuropathy following smoking marijuana. A 28-year-old man presented to the emergency room with sudden onset of bilateral blurring of the inferior visual field 8 h after smoking marijuana. His best-corrected visual acuity was 20/30 in the right eye and 20/20 in the left eye. Fundus examination revealed blurring of the optic disc margins in both eyes and a splinter haemorrhage in the right eye. Bilateral inferior visual field defects were detected with greater severity on the right side. Optical coherence tomography confirmed the diagnosis of bilateral optic neuropathy. A urine drug screen test was positive for tetrahydrocannabinol, which is the primary active ingredient in cannabinoids. The rest of the neurological examination and imaging were normal. The patient was treated with intravenous corticosteroids and an anti-platelet drug. His vision recovered to 20/20 in both eyes, with complete resolution of the field defect over a follow-up of 6 months. Optic neuropathy following marijuana abuse is unusual. The results of our report emphasise the need for awareness of marijuana-associated optic neuropathy as part of ocular adverse effects of marijuana intoxication.

A review of cannabis allergy in the early days of legalization

Cannabis allergy is a burgeoning field; consequently, research is still in its infancy and allergists' knowledge surrounding this topic is limited. As cannabis legalization expands across the world, it is anticipated that there will be an increase in cannabis use. Thus, we hypothesize that a concomitant rise in the incidence of allergy to this plant can be expected. Initiatives aimed at properly educating health care professionals are therefore necessary. This review presents the most up-to-date information on a broad range of topics related to cannabis allergy. Although the clinical features of cannabis allergy are becoming more well described and recognized, the tools available to make a correct diagnosis are meager and often poorly accessible. In addition, research on cannabis allergy is still taking its first steps, and new and potentially groundbreaking findings in this field are expected to occur in the next few years. Finally, although therapeutic approaches are being developed, patient and physician education regarding cannabis allergy is certainly needed.

Association between marijuana use and electrocardiographic abnormalities by middle age: the Coronary Artery Risk Development in Young Adults (CARDIA) study

AIMS

To evaluate the prevalence of electrocardiogram (ECG) abnormalities in marijuana users as an indirect measure of subclinical cardiovascular disease (CVD).

DESIGN

Longitudinal and cross-sectional secondary data analysis from the CARDIA (Coronary Artery Risk Development in Young Adults) study.

SETTING

Four communities in the United States.

PARTICIPANTS

A total of 2585 participants from the 5115 black and white men and women recruited at age 18-30 years in 1985 to 1986 in CARDIA.

MEASUREMENTS

ECG abnormalities coded as minor and major abnormalities with the Minnesota code of electrocardiographic findings at year 20. Self-reported current (past 30 days) and computed cumulative life-time marijuana use (one 'marijuana-year' corresponds to 365 days of use) through assessments every 2-5 years. We fitted logistic regression models adjusting for sex, race, center, education, age, tobacco smoking, physical activity, alcohol use and body mass index.

FINDINGS

Among the 2585 participants with an ECG at year 20, mean age was 46, 57% were women, 45% were black; 83% had past exposure to marijuana and 11% were using marijuana currently. One hundred and seventy-three participants (7%) had major abnormalities and 944 (37%) had minor abnormalities. Comparing current with never use in multivariable-adjusted models, the odds ratio (OR) for major ECG abnormalities was 0.60 [95% confidence interval (CI) = 0.32-1.15] and for minor ECG abnormalities 1.21 (95% CI = 0.87-1.68). Results did not change after stratifying by sex and race. Cumulative marijuana use was not associated with ECG abnormalities.

CONCLUSION

In a middle-aged US population, life-time cumulative and occasional current marijuana use were not associated with increases in electrocardiogram abnormalities. This adds to the growing body of evidence that occasional marijuana use and cardiovascular disease events and markers of subclinical atherosclerosis are not associated.

Cardiovascular Effects of Medical Marijuana: A Systematic Review

Utilization of marijuana as a medicinal agent is becoming increasingly popular, and so far, 25 states have legalized it for medical purposes. However, there is emerging evidence that marijuana use can result in cardiovascular side effects, such as rhythm abnormalities, syncope/dizziness, and myocardial infarction, among others. Further, there are currently no stringent national standards or approval processes, like Food and Drug Administration (FDA) evaluation, in place to assess medical marijuana products. This review includes the largest up-to-date pooled population of patients with exposure to marijuana and reported cardiovascular effects. Although purported as benign by many seeking to advance the use of marijuana as an adjunctive medical therapy across the country, marijuana is associated with its own set of cardiovascular risks and deserves further definitive study and the same level of scrutiny we apply in research of all other types of medications. When used as a medicinal agent, marijuana should be regarded accordingly, and both clinical providers and patients must be aware of potential adverse effects associated with its use for early recognition and management.

A Literature Review of Cannabis and Myocardial Infarction-What Clinicians May Not Be Aware Of

Increasing legalization and expanding medicinal use have led to a significant rise in global cannabis consumption. With this development, we have seen a growing number of case reports describing adverse cardiovascular events, specifically, cannabis-induced myocardial infarction (MI). However, there are considerable knowledge gaps on this topic among health care providers. This review aims to provide an up-to-date review of the current literature, as well as practical recommendations for clinicians. We also focus on proposed mechanisms implicating cannabis as a risk factor for MI. We performed a comprehensive literature search using the MEDLINE, Cochrane, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Turning Research into Practice (TRIP) PRO databases for articles published between 2000 and 2018. A total of 92 articles were included. We found a significant number of reports describing cannabis-induced MI. This was especially prevalent among young healthy patients, presenting shortly after use. The most commonly proposed mechanisms included increased autonomic stimulation, altered platelet function, vasospasm, and direct toxic effects of smoke constituents. However, it is likely that the true pathogenesis is multifactorial. We should increase our pretest probability for MI in young patients presenting with chest pain. We also recommend against cannabis use in patients with known coronary artery disease, especially if they have stable angina. Finally, if patients are adamant about using cannabis, health care providers should recommend against smoking cannabis, avoidance of concomitant tobacco use, and use of the lowest delta-9-tetrahydrocannabinol dose possible. Data quality is limited to that of observational studies and case report data. Therefore, more clinical trials are needed to determine a definitive cause-and-effect relationship.

Cardiac Ischemia Associated With Marijuana Use in an Adolescent

With the increasing use of marijuana globally, including in pediatric populations, healthcare providers see more adverse health effects associated with this substance. This report details a case presentation of cardiac ischemia in an adolescent male associated with marijuana use. The patient presented with palpitations and chest pain shortly after consuming marijuana. Clinical workup demonstrated anterior ST-segment elevations and troponin elevation with no inflammatory marker elevation or findings of myocarditis on MRI. Extensive drug screening was only positive for marijuana, with a synthetic THC panel negative. These findings resolved after close observation and the patient was discharged in good clinical condition. This case shows a concerning presentation of marijuana-associated cardiac ischemia in an otherwise healthy adolescent, illustrating a potentially severe health concern with an increasingly common substance and demonstrating the need for pediatric centers to have a high index of suspicion for cardiac causes of chest pain when marijuana ingestion is involved even when there are no prior medical or cardiac risk factors.

Arrhythmia-related Hospitalization and Comorbid Cannabis Use Disorder: Trend Analysis in US Hospitals (2010-2014)

Objective

To study the trends of arrhythmia hospitalizations with cannabis use disorders (CUDs) in terms of demographic characteristics and inpatient outcomes.

Methods

We used the nationwide inpatient sample (NIS) data during the post-legalization period (2010-2014) and included 570,556 arrhythmia inpatients (age, 15-54 years), and 14,426 inpatients had comorbid CUD (2.53%). We used the linear-by-linear association test and independent-sample T-test for assessing the change in hospital outcomes in inpatients with CUD.

Results

Arrhythmia hospitalizations with CUD increased by 31% (2010-2014). This increasing trend was seen in adults (45-54 years, P < 0.001) and was predominant in males (77.6%). Hypertension (40.6%), hyperlipidemia (17.6%), and obesity (15%) were prevalent medical comorbidities with variable trends over the five years. Among substance use disorders, tobacco (50.9%), and alcohol (31.4%) were major comorbidities with a variable trend (P = 0.003 for each). There was a 71.4% increase in the inpatient mortality rate between 2010 (0.7%) and 2014 (1.2%). The mean length of stay was three days, and the total hospitalization charges have been increasing (P < 0.001), averaging $35,812 per hospital admission.

Conclusion

Chronic cannabis use or abuse worsens hospitalization outcomes in arrhythmic patients, and more clinical studies are needed to study the causal association between these conditions due to the rising mortality risk.

Cannabis Associated "High" Cardiovascular Morbidity and Mortality: Marijuana Smoke Like Tobacco Smoke? A Déjà Vu/Déjà Vécu Story?

BACKGROUND

Cannabis use has increased over the past several years as some countries have legalized its use for the treatment of certain medical conditions and/or for recreational use. Thus, concerns have risen about potential adverse health effects. Increasing number of reports have associated cannabis use with serious cardiovascular (CV) complications. Furthermore, there appears to be a likeness in the harmful health effects, especially on the CV and respiratory systems, of cannabis smoking to those of tobacco smoking.

OBJECTIVE

To review the CV effects of cannabis use and compare them with those of tobacco use.

METHODS

Articles were reviewed that were published in English literature reporting on cannabis and cannabinoid pharmacology and their effects on the CV system and their consequences. Emphasis was also placed on articles reporting on cannabis use in adolescents, exposure to secondhand smoke, its effect on exercise and finally its inter-relationship and similarities with tobacco use.

RESULTS

With growing cannabis use, an increasing number of reports have emerged associating marijuana use with serious and life-threatening CV complications, including acute coronary syndromes, potentially lethal cardiac arrhythmias and ischemic strokes. There are certain similarities of the deleterious CV and respiratory effects of cannabis smoking with those of tobacco smoking. Despite the difference in the active ingredients (tetrahydrocannabinol vs. nicotine), each substance produces a plethora of chemicals when smoked and these are largely identical; furthermore, due to different modes of smoking, cannabis chemicals are retained in the body for a longer time. Of course, concomitant tobacco and cannabis smoking is a perplexing factor in isolating damages specifically pertaining to cannabis use, while the health risk is additive. Although the mechanisms producing CV harm may be somewhat different between these two substances, the outcome appears similar, or even worse, as the effects may emerge at a younger age.

CONCLUSION

There is an increasing concern that, apart from the mental health problem with cannabis smoking, societies may be facing another wave of a déjà vu/déjà vécu phenomenon similar to the tobacco smoking story.

Cardiovascular Complications of Marijuana and Related Substances: A Review

The recreational use of cannabis has sharply increased in recent years in parallel with its legalization and decriminalization in several countries. Commonly, the traditional cannabis has been replaced by potent synthetic cannabinoids and cannabimimetics in various forms. Despite overwhelming public perception of the safety of these substances, an increasing number of serious cardiovascular adverse events have been reported in temporal relation to recreational cannabis use. These have included sudden cardiac death, vascular (coronary, cerebral and peripheral) events, arrhythmias and stress cardiomyopathy among others. Many of the victims of these events are relatively young men with few if any cardiovascular risk factors. However, there are reasons to believe that older individuals and those with risk factors for or established cardiovascular disease are at even higher danger of such events following exposure to cannabis. The pathophysiological basis of these events is not fully understood and likely encompasses a complex interaction between the active ingredients (particularly the major cannabinoid, Δ9-tetrahydrocannabinol), and the endo-cannabinoid system, autonomic nervous system, as well as other receptor and non-receptor mediated pathways. Other complicating factors include opposing physiologic effects of other cannabinoids (predominantly cannabidiol), presence of regulatory proteins that act as metabolizing enzymes, binding molecules, or ligands, as well as functional polymorphisms of target receptors. Tolerance to the effects of cannabis may also develop on repeated exposures at least in part due to receptor downregulation or desensitization. Moreover, effects of cannabis may be enhanced or altered by concomitant use of other illicit drugs or medications used for treatment of established cardiovascular diseases. Regardless of these considerations, it is expected that the current cannabis epidemic would add significantly to the universal burden of cardiovascular diseases.

Medical Marijuana: Current Concepts, Pharmacological Actions of Cannabinoid Receptor Mediated Activation, and Societal Implications

PURPOSE OF REVIEW

The purpose of the following review is to summarize the history and current policies related to marijuana use and prevalence, basic and clinical science pharmacological literature regarding efficacy, subpopulations of concern, and varying policies regarding its use at present.

RECENT FINDINGS

With the increasingly widespread utilization of marijuana, there is also a growing complexity of public health policy, regulation, and necessity to further assess the medical indications and adverse long-term effects of marijuana use. Health care providers as well as the general public must be prepared to become familiar and up-to-date with medical literature, legislation, and educational material regarding medical marijuana.

Brugada Pattern in Diabetic Ketoacidosis: A Case Report and Scoping Study

Brugada syndrome is a rare cardiac arrhythmia which is associated with right bundle branch block pattern (RBBB) and ST-segment elevation in right precordial leads. SCNA5 mutation is the most common genetic abnormality associated with Brugada syndrome. Brugada pattern not related to genetic mutations has been previously reported in the setting of fever, metabolic conditions, lithium use, marijuana and cocaine abuse, ischemia and pulmonary embolism, myocardial and pericardial diseases. Multiple isolated cases of Brugada pattern associated with diabetic ketoacidosis (DKA) have been previously reported. We here present a case of type 1 Brugada pattern in a 23 year-old-male who presented with DKA. Brugada pattern in DKA is attributed to acidosis and multiple electrolyte abnormalities including hyperkalemia which alter ion channel expression in the heart thus leading to Brugada pattern which subsequently resolved with treatment of DKA. In such patients, Brugada pattern is not reproducible on procainamide induction cardiac electrophysiology study (EPS). Our scoping study demonstrates male predominance 20/22 cases of (DELETE this highlighted area) Brugada pattern in DKA, a finding that is consistent with prevalence of this disease among males.

Addictive drugs, arrhythmias, and cardiac inward rectifiers

In many addictive drugs including alcohol and nicotine, proarrhythmic effects were reported. This review provides an overview of the current knowledge in this field (with a focus on the inward rectifier potassium currents) to promote the lacking data and appeal for their completion, thus, to improve understanding of the proarrhythmic potential of addictive drugs.

Role of cannabis in cardiovascular disorders

The growing popularity of medical and recreational consumption of cannabis, especially among the youth, raises immediate concerns regarding its safety and long-terms effects. The cardiovascular effects of cannabis are not well known. Cannabis consumption has been shown to cause arrhythmia including ventricular tachycardia, and potentially sudden death, and to increase the risk of myocardial infarction (MI). These effects appear to be compounded by cigarette smoking and precipitated by excessive physical activity, especially during the first few hours of consumption. Cannabinoids, or the active compounds of cannabis, have been shown to have heterogeneous effects on central and peripheral circulation. Acute cannabis consumption has been shown to cause an increase in blood pressure, specifically systolic blood pressure (SBP), and orthostatic hypotension. Cannabis use has been reported to increase risk of ischemic stroke, particularly in the healthy young patients. The endocannabinoid system (ECS) is currently considered as a promising therapeutic target in the management of several disease conditions. Synthetic cannabinoids (SCs) are being increasingly investigated for their therapeutic effects; however, the value of their benefits over possible complications remains controversial. Despite the considerable research in this field, the benefits of cannabis and its synthetic derivatives remains questionable even in the face of an increasingly tolerating attitude towards recreational consumption and promotion of the therapeutic complications. More efforts are needed to increase awareness among the public, especially youth, about the cardiovascular risks associated with cannabis use and to disseminate the accumulated knowledge regarding its ill effects.

Marijuana Use and Cardiovascular Disease

Marijuana is currently the most used illicit substance in the world. With the current trend of decriminalization and legalization of marijuana in the US, physicians in the US will encounter more patients using marijuana recreationally over a diverse range of ages and health states. Therefore, it is relevant to review marijuana's effects on human cardiovascular physiology and disease. Compared with placebo, marijuana cigarettes cause increases in heart rate, supine systolic and diastolic blood pressures, and forearm blood flow via increased sympathetic nervous system activity. These actions increase myocardial oxygen demand to a degree that they can decrease the time to exercise-induced angina in patients with a history of stable angina. In addition, marijuana has been associated with triggering myocardial infarctions (MIs) in young male patients. Smoking marijuana has been shown to increase the risk of MI onset by a factor of 4.8 for the 60 minutes after marijuana consumption, and to increase the annual risk of MI in the daily cannabis user from 1.5% to 3% per year. Human and animal models suggest that this effect may be due to coronary arterial vasospasm. However, longitudinal studies have indicated that marijuana use may not have a significant effect on long-term mortality. While further research is required to definitively determine the impact of marijuana on cardiovascular disease, it is reasonable to recommend against recreational marijuana use, especially in individuals with a history of coronary artery disorders.

Risks associated with the non-medicinal use of cannabis

BACKGROUND

Cannabis is the most commonly consumed illicit drug around the world; in Germany, about 4.5% of all adults use it each year. Intense cannabis use is associated with health risks. Evidence-based treatments are available for health problems caused by cannabis use.

METHODS

Selective literature review based on a search of the PubMed database, with special emphasis on systematic reviews, meta-analyses, cohort studies, randomized controlled trials (RCTs), case-control studies, and treatment guidelines.

RESULTS

The delta-9-tetrahydrocannabinol content of cannabis products is rising around the world as a result of plant breeding, while cannabidiol, in contrast, is often no longer detectable. Various medical conditions can arise acutely after cannabis use, depending on the user's age, dose, frequency, mode and situation of use, and individual disposition; these include panic attacks, psychotic symptoms, deficient attention, impaired concentration, motor incoordination, and nausea. In particular, intense use of high doses of cannabis over many years, and the initiation of cannabis use in adolescence, can be associated with substance dependence (DSM-5; ICD-10), specific withdrawal symptoms, cognitive impairment, affective disorders, psychosis, anxiety disorders, and physical disease outside the brain (mainly respiratory and cardiovascular conditions). At present, the most effective way to treat cannabis dependence involves a combination of motivational encouragement, cognitive behavioral therapy, and contingency management (level 1a evidence). For adolescents, family therapy is also recommended (level 1a evidence). No pharmacological treatments can be recommended to date, as evidence for their efficacy is lacking.

CONCLUSION

Further research is needed to elucidate the causal relationships between intense cannabis use and potential damage to physical and mental health. Health problems due to cannabis use can be effectively treated.

Cannabinoids: Medical implications

Herbal cannabis has been used for thousands of years for medical purposes. With elucidation of the chemical structures of tetrahydrocannabinol (THC) and cannabidiol (CBD) and with discovery of the human endocannabinoid system, the medical usefulness of cannabinoids has been more intensively explored. While more randomized clinical trials are needed for some medical conditions, other medical disorders, like chronic cancer and neuropathic pain and certain symptoms of multiple sclerosis, have substantial evidence supporting cannabinoid efficacy. While herbal cannabis has not met rigorous FDA standards for medical approval, specific well-characterized cannabinoids have met those standards. Where medical cannabis is legal, patients typically see a physician who "certifies" that a benefit may result. Physicians must consider important patient selection criteria such as failure of standard medical treatment for a debilitating medical disorder. Medical cannabis patients must be informed about potential adverse effects, such as acute impairment of memory, coordination and judgment, and possible chronic effects, such as cannabis use disorder, cognitive impairment, and chronic bronchitis. In addition, social dysfunction may result at work/school, and there is increased possibility of motor vehicle accidents. Novel ways to manipulate the endocannbinoid system are being explored to maximize benefits of cannabinoid therapy and lessen possible harmful effects.

Coronary thrombosis and marijuana smoking: a case report and narrative review of the literature

We encountered evidence of myocardial infarction due to coronary thrombosis in an autopsy of an occasional marijuana smoker. These findings prompted us to perform a narrative review of the literature to determine when post-mortem toxicological tests may support a temporal relationship between marijuana smoking and cardiovascular disease. Toxicological examination showed the presence of Δ-9-tetrahydrocannabinol, its main metabolite and cannabinol in blood and urine. Quali-quantitative analysis revealed that Δ-9-tetrahydrocannabinol was taken within 2 h of the onset of cardiovascular symptoms, according to circumstantial data. Post-mortem toxicological results must take into account the degradation and post-mortem redistribution of analytes. However, for any inference about the specific cardiovascular triggering effect of Δ-9-tetrahydrocannabinol intake, we maintain that cannabinoid analysis in blood samples must be considered an essential requirement to estimate the time of last intake and avoid incomplete documentation. The literature, combined with the present case report, highlights an association between marijuana use and negative cardiovascular events, although few authors have supported their conclusions with toxicological results. Thus, additional research is needed.

Myocardial Ischemia Secondary to Synthetic Cannabinoid (K2) Use in Pediatric Patients

K2 is a synthetic cannabinoid that has potential cardiovascular side effects, including myocardial ischemia, myocardial infarction, and arrhythmias. Cardiac testing of pediatric patients is often not performed owing to a lack of symptomatology. We report a series of pediatric patients with concern for myocardial ischemia temporally associated with K2 exposure.

Downstream effects of endocannabinoid on blood cells: implications for health and disease

Endocannabinoids (eCBs), among which N-arachidonoylethanolamine (AEA) and 2-arachidonoylglycerol (2-AG) are the most biologically active members, are polyunsaturated lipids able to bind cannabinoid, vanilloid and peroxisome proliferator-activated receptors. Depending on the target engaged, these bioactive mediators can regulate different signalling pathways, at both central and peripheral levels. The biological action of eCBs is tightly controlled by a plethora of metabolic enzymes which, together with the molecular targets of these substances, form the so-called "endocannabinoid system". The ability of eCBs to control manifold peripheral functions has received a great deal of attention, especially in the light of their widespread distribution in the body. In particular, eCBs are important regulators in blood, where they modulate haematopoiesis, platelet aggregation and apoptosis, as well as chemokine release and migration of immunocompetent cells. Here, we shall review the current knowledge on the pathophysiological roles of eCBs in blood. We shall also discuss the involvement of eCBs in those disorders affecting the haematological system, including cancer and inflammation. Knowledge gained to date underlines a fundamental role of the eCB system in blood, thus suggesting that it may represent a therapeutic promise for a broad range of diseases involving impaired hematopoietic cell functions.

[Cannabis use: what to do in general practice?]

Cannabis use is now more frequent than alcohol drinking or tobacco smoking among young people (15-34years), whereas it may induce numerous medical aftermaths. Identifying and assessing cannabis use in general practice have become a current public health issue. The two steps of screening consist in spotting risky use of cannabis, and then in checking criteria for cannabis use disorder (CUD). Risky use requires a "brief intervention" by the general practitioner (GP). In case of CUD, the new DSM-5 criteria allow measuring the severity of the subsequent disorder, and listing the medical and social consequences. Using these criteria can help the GP to decide when the patient should be referred to an addiction-specialized unit. The GP has also to spot the different physical and psychiatric complications of cannabis use, in order to coordinate care between the different specialists.

Adverse cardiovascular, cerebrovascular, and peripheral vascular effects of marijuana inhalation: what cardiologists need to know

Marijuana is the most widely used illicit drug, with approximately 200 million users worldwide. Once illegal throughout the United States, cannabis is now legal for medicinal purposes in several states and for recreational use in 3 states. The current wave of decriminalization may lead to more widespread use, and it is important that cardiologists be made aware of the potential for marijuana-associated adverse cardiovascular effects that may begin to occur in the population at a greater frequency. In this report, the investigators focus on the known cardiovascular, cerebrovascular, and peripheral effects of marijuana inhalation. Temporal associations between marijuana use and serious adverse events, including myocardial infarction, sudden cardiac death, cardiomyopathy, stroke, transient ischemic attack, and cannabis arteritis have been described. In conclusion, the potential for increased use of marijuana in the changing legal landscape suggests the need for the community to intensify research regarding the safety of marijuana use and for cardiologists to maintain an awareness of the potential for adverse effects.

Marijuana: current concepts(†)

Marijuana (cannabis) remains a controversial drug in the twenty-first century. This paper considers current research on use of Cannabis sativa and its constituents such as the cannabinoids. Topics reviewed include prevalence of cannabis (pot) use, other drugs consumed with pot, the endocannabinoid system, use of medicinal marijuana, medical adverse effects of cannabis, and psychiatric adverse effects of cannabis use. Treatment of cannabis withdrawal and dependence is difficult and remains mainly based on psychological therapy; current research on pharmacologic management of problems related to cannabis consumption is also considered. The potential role of specific cannabinoids for medical benefit will be revealed as the twenty-first century matures. However, potential dangerous adverse effects from smoking marijuana are well known and should be clearly taught to a public that is often confused by a media-driven, though false message and promise of benign pot consumption.

Modulating the endocannabinoid system in human health and disease--successes and failures

The discovery of the endocannabinoid system, comprising the G-protein coupled cannabinoid 1 and 2 receptors (CB1/2), their endogenous lipid ligands or endocannabinoids, and synthetic and metabolizing enzymes, has triggered an avalanche of experimental studies implicating the endocannabinoid system in a growing number of physiological/pathological functions. These studies have also suggested that modulating the activity of the endocannabinoid system holds therapeutic promise for a broad range of diseases, including neurodegenerative, cardiovascular and inflammatory disorders; obesity/metabolic syndrome; cachexia; chemotherapy-induced nausea and vomiting; and tissue injury and pain, amongst others. However, clinical trials with globally acting CB1 antagonists in obesity/metabolic syndrome, and other studies with peripherally-restricted CB1/2 agonists and inhibitors of the endocannabinoid metabolizing enzyme in pain, have introduced unexpected complexities, suggesting that a better understanding of the pathophysiological role of the endocannabinoid system is required to devise clinically successful treatment strategies.

Marijuana use and long-term mortality among survivors of acute myocardial infarction

BACKGROUND

Smoking marijuana has been reported to increase risk of myocardial infarction (MI) immediately after use, but less is known about the long-term impact of marijuana use among patients with established coronary disease.

METHODS

The Determinants of MI Onset Study is a multicenter inception cohort study of myocardial infarction (MI) patients enrolled in 1989 to 1996 and followed up for mortality using the National Death Index. In an initial analysis of 1,935 MI survivors followed up for a median of 3.8 years, we found an increased mortality rate among marijuana users. The current article includes 3,886 Determinants of MI Onset Study patients followed up for up to 18 years. We used Cox proportional hazards models to calculate the hazard ratio and 95% CI for the association between marijuana use and mortality and a propensity score matched analysis to further control confounding.

RESULTS

Over up to 18 years of follow-up, 519 patients died, including 22 of the 109 reporting marijuana use in the year before their MI. There was no statistically significant association between marijuana use and mortality. Compared with nonusers, the mortality rate was 29% higher (95% CI 0.81-2.05, P = .28) among those reporting any marijuana use.

CONCLUSIONS

Habitual marijuana use among patients presenting with acute MI was associated with an apparent increased mortality rate over the following 18 years that did not reach nominal statistical significance. Larger studies with repeated measures of marijuana use are needed to definitively establish whether there are adverse cardiovascular consequences of smoking marijuana among patients with established coronary heart disease.

Spontaneous multivessel coronary artery dissection associated with cannabis use

Cannabis is the most widely used illicit drug in the world. It is generally considered to be a drug with low toxicity. Nevertheless, there are several case reports of myocardial infarction following cannabis use in otherwise low-risk individuals. We report the first case of a cannabis user presenting with acute coronary syndrome related to multivessel coronary artery dissection.