Propranolol effects on acute marihuana intoxication in man

Evaluation of the cardiovascular risk induced by cannabis use from a series of 43 autopsy cases

The aim of this monocentric observational autopsy study was to confirm the existence of a link between cannabis use and cardiovascular risk. It was based on the analysis of autopsy findings, cardiovascular pathological findings, and toxicological data in 43 autopsy cases of people who died with tetrahydrocannabinol (THC) in their blood over a 2-year period. Hair analysis was performed when available (n = 40) to distinguish between occasional and chronic cannabis use and to take into account other possible exposures, including smoking, drug consumption, and the use of other drugs of abuse (mainly cocaine, heroin, and amphetamine). A statistically significant association (Fisher's exact test, p < 0.001) was found between cannabis use, an undetermined manner of death, and the presence of an arrhythmogenic cardiac condition. An association was also found between cannabis use and the presence of advanced coronary heart disease (p = 0.01), heart disease (including ischemic heart disease, p = 0.003), or cardiomyopathy (p = 0.01). Through its systemic vascular action, cannabis could be a factor in triggering sudden death in subjects with arrhythmogenic cardiac conditions. In view of this finding, the mode of death of subjects who died in the presence of THC in the blood would in most cases be an "accident." These results highlight the potential adverse cardiac effects associated with cannabis use.

[Does medicinal cannabis or cannabis consumption have an influence on the perioperative anesthesiological management?]

The greatly increasing use of medicinal cannabis products as well as the upcoming legalization of cannabis not only require a general re-evaluation of how these substances might be classified as illegal drugs, but also enforce a critical view on the possible consequences that cannabis consumption might have on the anesthesiological strategies applied for surgical procedures. Although high-quality clinical studies are still lacking, several clinical studies meanwhile indicate that an active preoperative cannabis consumption seems to be associated with relevant pathophysiological aspects. Patients who regularly consume high doses of cannabis show an increased risk of cardiovascular and respiratory complications as well as the postoperative nausea and vomitting (PONV) associated with anesthesia. This also applies to relatively young patients. Moreover, the requirements for general anesthetics and analgesics seem to be increased in the context of cannabis consumption, e.g., these patients may require additional efforts when it comes to monitoring the depth of anesthesia and providing a personalized multimodal postoperative pain therapy. It therefore appears to be meaningful to carefully assess and document the extent and duration of the preoperative cannabis consumption during the preoperative assessment. Furthermore, the possibility to perform a preoperative dose reduction of cannabis products in cases with high doses should at least be considered. As the consumption of cannabis is not only increasing in Germany but also worldwide, important future insights will offer a guide towards a safe handling of cannabis in perioperative medicine in the coming years.

Why Do Marijuana and Synthetic Cannabimimetics Induce Acute Myocardial Infarction in Healthy Young People?

The use of cannabis preparations has steadily increased. Although cannabis was traditionally assumed to only have mild vegetative side effects, it has become evident in recent years that severe cardiovascular complications can occur. Cannabis use has recently even been added to the risk factors for myocardial infarction. This review is dedicated to pathogenetic factors contributing to cannabis-related myocardial infarction. Tachycardia is highly important in this respect, and we provide evidence that activation of CB₁ receptors in brain regions important for cardiovascular regulation and of presynaptic CB₁ receptors on sympathetic and/or parasympathetic nerve fibers are involved. The prototypical factors for myocardial infarction, i.e., thrombus formation and coronary constriction, have also been considered, but there is little evidence that they play a decisive role. On the other hand, an increase in the formation of carboxyhemoglobin, impaired mitochondrial respiration, cardiotoxic reactions and tachyarrhythmias associated with the increased sympathetic tone are factors possibly intensifying myocardial infarction. A particularly important factor is that cannabis use is frequently accompanied by tobacco smoking. In conclusion, additional research is warranted to decipher the mechanisms involved, since cannabis use is being legalized increasingly and Δ⁹-tetrahydrocannabinol and its synthetic analogue nabilone are indicated for the treatment of various disease states.

Considerations for Cannabinoids in Perioperative Care by Anesthesiologists

Increased usage of recreational and medically indicated cannabinoid compounds has been an undeniable reality for anesthesiologists in recent years. These compounds’ complicated pharmacology, composition, and biological effects result in challenging issues for anesthesiologists during different phases of perioperative care. Here, we review the existing formulation of cannabinoids and their biological activity to put them into the context of the anesthesia plan execution. Perioperative considerations should include a way to gauge the patient’s intake of cannabinoids, the ability to gain consent properly, and vigilance to the increased risk of pulmonary and airway problems. Intraoperative management in individuals with cannabinoid use is complicated by the effects cannabinoids have on general anesthetics and depth of anesthesia monitoring while simultaneously increasing the potential occurrence of intraoperative hemodynamic instability. Postoperative planning should involve higher vigilance to the risk of postoperative strokes and acute coronary syndromes. However, most of the data are not up to date, rending definite conclusions on the importance of perioperative cannabinoid intake on anesthesia management difficult.

Cannabis and Athletic Performance

Cannabis is widely used for both recreational and medicinal purposes on a global scale. There is accumulating interest in the use of cannabis and its constituents for athletic recovery, and in some instances, performance. Amidst speculation of potential beneficial applications, the effects of cannabis and its two most abundant constituents, delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), remain largely un-investigated. The purpose of this review is to critically evaluate the literature describing the effects of whole cannabis, THC, and CBD, on athletic performance and recovery. While investigations of whole cannabis and THC have generally shown either null or detrimental effects on exercise performance in strength and aerobic-type activities, studies of sufficient rigor and validity to conclusively declare ergogenic or ergolytic potential in athletes are lacking. The ability of cannabis and THC to perturb cardiovascular homeostasis warrants further investigation regarding mechanisms by which performance may be affected across different exercise modalities and energetic demands. In contrast to cannabis and THC, CBD has largely been scrutinized for its potential to aid in recovery. The beneficial effects of CBD on sleep quality, pain, and mild traumatic brain injury may be of particular interest to certain athletes. However, research in each of these respective areas has yet to be thoroughly investigated in athletic populations. Elucidating the effects of whole cannabis, THC, and CBD is pertinent for both researchers and practitioners given the widespread use of these products, and their potential to interact with athletes' performance and recovery.

Cardiac sudden death in a young cannabis user

We report a case of sudden death due to acute coronary syndrome (ACS) in a young cannabis user. A man in his late thirties died at home, and marijuana was found. The autopsy revealed severe occlusion by an atherosclerotic plaque in the left anterior descending artery. The histopathological examination revealed ischemic changes, likely caused by cannabis-induced sympathetic β-adrenergic stimulation. Both cannabinoid receptors (CB1 and CB2) were expressed in the atherosclerotic lesions. The CB2 expression was higher than CB1 expression in the atherosclerotic plaque, corresponding to macrophage infiltration. Since cannabis is regarded as a casual drug due to its lower levels of dependency, some individuals have supported legalized marijuana use. However, this case report will provide cautions on the casual use of cannabis.

Mechanisms for the Risk of Acute Coronary Syndrome and Arrhythmia Associated With Phytogenic and Synthetic Cannabinoid Use

Phytogenic cannabinoids from Cannabis sativa and synthetic cannabinoids are commonly used substances for their recreational and medicinal properties. There are increasing reports of cardiotoxicity in close temporal association with cannabinoid use in patients with structurally normal hearts and absence of coronary arterial disease. Associated adverse events include myocardial ischemia, conduction abnormalities, arrhythmias, and sudden death. This review details the effects of phytogenic and synthetic cannabinoids on diverse receptors based on evidence from in vitro, human, and animal studies to establish a molecular basis for these deleterious clinical effects. The synergism between endocannabinoid dysregulation, cannabinoid receptor, and noncannabinoid receptor binding, and impact on cellular ion flux and coronary microvascular circulation is delineated. Pharmacogenetic factors placing certain patients at higher risk for cardiotoxicity are also correlated with the diverse effects of cannabinoids.

Marijuana use and acute myocardial infarction: A systematic review of published cases in the literature

BACKGROUND AND OBJECTIVE

Marijuana use has gained popularity following legalization in the US. Marijuana can affect the heart through various mechanisms. This study aims to conduct a systematic review of published case reports of individuals with acute myocardial infarction (AMI) following marijuana use.

METHODS

We conducted a systematic review of literature, including case reports, case series, and the letter to the editor on MEDLINE. Forty-six studies were included, with a total number of 62 patients with AMI and marijuana use.

RESULTS

The mean age was 27.7 (±10.3) years with male predominance. About 3.7 g marijuana was used for an average of 9.7 years by the patients. From the cases reporting the onset of AMI symptoms, the average time was within 5 h after last marijuana use. The angiographic findings were normal in 36.8% of cases. In 42.1% of individuals, the left anterior descending coronary artery was occluded, making it the most common artery involved, followed by the right coronary artery (10.5%). Most cases were managed medically, followed by thrombectomy and stent placement, and percutaneous transluminal coronary angioplasty (PTCA). Complications included cardio-embolic stroke, and seven deaths were reported.

CONCLUSION

It is important to consider episodic marijuana use as a significant risk factor of AMI, particularly in individuals with no cardiac risk factors, as delay in management can result in fatal outcomes including increased risk of mortality.

Recurrent STEMI Precipitated by Marijuana Use: Case Report and Literature Review

Marijuana abuse is rapidly growing and currently it is the most coimnon drug of abuse in the United States due to increased legalization for recreational and medicinal use. Delta 9-tetrahydrocannibol, the main psychoactive compound in marijuana, acts via the endocannabinoid system to elicit various cardiovascular physiological effects, and has been associated with many adverse cardiovascular effects such as acute coronary syndrome, arrhythmias, and sudden cardiac death that have previously been reported by our group and others. We present a case of a 30-year-old African-American male with no cardiovascular disease (CVD) risk factors with recurrent ST-segment elevation myocardial infarctions (STEMI) whose coronary angiography revealed recurrent 100% occlusion of the left anterior descending artery (LAD) in the setting of marijuana smoking. It was the patient's third STEMI with 100% occlusion of the LAD with each STEMI secondary to thrombosis of a different region of the LAD. Marijuana use was confirmed by urine toxicology screening at each STEMI presentation. Coronary angiography on multiple occasions was negative for stenosis of other epicardial coronary arteries, and coronary calcimn scoring was zero. Evaluation for other cardiovascular risk factors including family history of premature coronary artery disease, dyslipidemia, diabetes, and hypercoagulable disorders was negative. Further studies are required to elucidate the mechanisms of marijuana-associated coronary thrombosis and myocardial infarction.

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.

Are Alcohol Anti-relapsing and Alcohol Withdrawal Drugs Useful in Cannabinoid Users?

Cannabinoids are still classified as illegal psychoactive drugs despite their broad and increasingly acknowledged therapeutic potential. These substances are most famous for their wide recreational use, particularly among young adults to either alter the state of consciousness, intensify pleasure induced by other psychoactive substances or as an alternative to the previously abused drugs. It is important to emphasize that cannabinoids are often taken together with a variety of medications intended for the treatment of alcohol use disorder (AUD) or alcohol withdrawal syndrome (AWS). These medications include disulfiram, acamprosate, and naltrexone. In this paper, we summarize recent advances in the knowledge of possible beneficial effects and interactions between cannabinoids and drugs commonly used for treatment of AUD and AWS either comorbid or existing as a separate disorder.

Care and feeding of the endocannabinoid system: a systematic review of potential clinical interventions that upregulate the endocannabinoid system

Background

The “classic” endocannabinoid (eCB) system includes the cannabinoid receptors CB₁ and CB₂, the eCB ligands anandamide (AEA) and 2-arachidonoylglycerol (2-AG), and their metabolic enzymes. An emerging literature documents the “eCB deficiency syndrome” as an etiology in migraine, fibromyalgia, irritable bowel syndrome, psychological disorders, and other conditions. We performed a systematic review of clinical interventions that enhance the eCB system—ways to upregulate cannabinoid receptors, increase ligand synthesis, or inhibit ligand degradation.

Methodology/Principal Findings

We searched PubMed for clinical trials, observational studies, and preclinical research. Data synthesis was qualitative. Exclusion criteria limited the results to 184 in vitro studies, 102 in vivo animal studies, and 36 human studies. Evidence indicates that several classes of pharmaceuticals upregulate the eCB system, including analgesics (acetaminophen, non-steroidal anti-inflammatory drugs, opioids, glucocorticoids), antidepressants, antipsychotics, anxiolytics, and anticonvulsants. Clinical interventions characterized as “complementary and alternative medicine” also upregulate the eCB system: massage and manipulation, acupuncture, dietary supplements, and herbal medicines. Lifestyle modification (diet, weight control, exercise, and the use of psychoactive substances—alcohol, tobacco, coffee, cannabis) also modulate the eCB system.

Conclusions/Significance

Few clinical trials have assessed interventions that upregulate the eCB system. Many preclinical studies point to other potential approaches; human trials are needed to explore these promising interventions.

Cannabinoid modulation of noradrenergic circuits: implications for psychiatric disorders

The interaction between the endocannabinoid system and catecholaminergic circuits has gained increasing attention as it is recognized that the development of synthetic cannabinoid receptor agonists/antagonists or compounds targeting endocannabinoid synthesis/metabolism may hold some therapeutic potential for the treatment of psychiatric disorders. The noradrenergic system plays a critical role in the modulation of emotional state, primarily related to anxiety, arousal, and stress. Recent evidence suggests that the endocannabinoid system mediates stress responses and emotional homeostasis, in part, by targeting noradrenergic circuits. This review summarizes our current knowledge regarding the anatomical substrates underlying regulation of noradrenergic circuitry by the endocannabinoid system. It then presents biochemical evidence showing an important effect of cannabinoid modulation on adrenergic receptor signaling. Finally, new evidence from behavioral pharmacology studies is provided demonstrating that norepinephrine is a critical determinant of cannabinoid-induced aversion, adding another dimension to how central noradrenergic circuitry is regulated by the cannabinoid system.

Pharmacological interventions in the treatment of the acute effects of cannabis: a systematic review of literature

BACKGROUND

Cannabis intoxication is related to a number of physical and mental health risks with ensuing social costs. However, little attention has been given to the investigation of possible pharmacological interactions in this condition.

OBJECTIVE

To review the available scientific literature concerning pharmacological interventions for the treatment of the acute effects of cannabis.

METHODS

A search was performed on the Pubmed, Lilacs, and Scielo online databases by combining the terms cannabis, intoxication, psychosis, anxiety, and treatment. The articles selected from this search had their reference lists checked for additional publications related to the topic of the review.

RESULTS

The reviewed articles consisted of case reports and controlled clinical trials and are presented according to interventions targeting the physiological, psychiatric, and cognitive symptoms provoked by cannabis. The pharmacological interventions reported in these studies include: beta-blockers, antiarrhythmic agents, antagonists of CB-1 and GABA-benzodiazepine receptors, antipsychotics, and cannabidiol.

CONCLUSION

Although scarce, the evidence on pharmacological interventions for the management of cannabis intoxication suggests that propanolol and rimonabant are the most effective compounds currently available to treat the physiological and subjective effects of the drug. Further studies are necessary to establish the real effectiveness of these two medications, as well as the effectiveness of other candidate compounds to counteract the effects of cannabis intoxication, such as cannabidiol and flumazenil.

Cardiovascular system effects of marijuana

Marijuana and delta9-tetrahydrocannabinol (THC) increase heart rate, slightly increase supine blood pressure, and on occasion produce marked orthostatic hypotension. Cardiovascular effects in animals are different, with bradycardia and hypotension the most typical response. Cardiac output increases, and peripheral vascular resistance and maximum exercise performance decrease. Tolerance to most of the initial cardiovascular effects appears rapidly. With repeated exposure, supine blood pressure decreases slightly, orthostatic hypotension disappears, blood volume increases, heart rate slows, and circulatory responses to exercise and Valsalva maneuver are diminished, consistent with centrally mediated, reduced sympathetic, and enhanced parasympathetic activity. Receptor-mediated and probably nonneuronal sites of action account for cannabinoid effects. The endocannabinoid system appears important in the modulation of many vascular functions. Marijuana's cardiovascular effects are not associated with serious health problems for most young, healthy users, although occasional myocardial infarction, stroke, and other adverse cardiovascular events are reported. Marijuana smoking by people with cardiovascular disease poses health risks because of the consequences of the resulting increased cardiac work, increased catecholamine levels, carboxyhemoglobin, and postural hypotension.

Phospholipase participation in cannabinoid-induced release of free arachidonic acid

The exposure of cells in culture to cannabinoids results in a rapid and significant mobilization of phospholipid bound arachidonic acid. In vivo, this effect has been observed as a rise in eicosanoid tissue levels that may account for some of the pharmacological actions of delta 9-tetrahydrocannabinol (THC), the major psychoactive cannabinoid. Fluoroaluminate pretreatment of mouse peritoneal cells potently reduced the cannabinoid response, while promoting arachidonate release on its own, consistent with earlier observations that this effect may be a receptor/G-protein-mediated process. Further support for receptor mediation was the demonstration of saturable, high-affinity cannabinoid binding in these cells. THC potency was reduced in the presence of ethanol, and was accompanied by significant increases in phosphatidylethanol (PdEt) levels, a unique product of phospholipase D (PLD) activity. THC-dependent arachidonate release was reduced partially in similar amounts by either propranolol or wortmannin, further implicating PLD as a mediator of THC action. A central role for diacylglyceride (DAG), a secondary product of PLD metabolism, in this THC-induced process, both as a source of arachidonate and as a stimulator of protein kinase C (PKC), is supported by the data in this report. Cells exposed to phorbol ester for 18 hr prior to THC challenge became less responsive, indicating a possible role for PKC. The involvement of PKC further suggests participation by phospholipase A2 (PLA2) whose activity may be regulated by the former. Treatment of cells with interleukin-1 alpha, an agent known to elevate PLA2 levels, caused an increase in the THC response, supporting a role for this enzyme in the release reaction. Direct evidence, by immunoblotting, for the activation and phosphorylation of PLA2 by THC was also obtained. In summary, the evidence presented in this report indicates that THC-induced arachidonic acid release occurs through a series of events that are consistent with a receptor-mediated process involving the stimulation of one or more phospholipases.

Influence of cilazapril on memory functions and sleep behaviour in comparison with metoprolol and placebo in healthy subjects

1. In a controlled, randomized, double-blind study the influence of cilazapril and metoprolol on learning and memory functions and on sleep behaviour was investigated in healthy young volunteers under steady-state conditions. Twenty-three subjects were given either 2.5 mg cilazapril, 200 mg metoprolol, or placebo for 14 days in a latin square design separated by washout periods of 7 days. 2. To test memory functions different modalities--verbal, visual, numerical associative and two dimensional spatial memory were tested for recent anterograde recall, both short-term (less than 10 s) and middle-term (up to 15 min) were selected. The test had a content similar to that used in daily life situations. The sleep behaviour was tested both by objective (all night sleep EEG) and subjective measures. 3. Neither antihypertensive drug had an observable influence on memory performance at the dosages used under steady-state conditions. However, sleep was disturbed during metoprolol, while cilazapril could not be differentiated from placebo. The effects of metoprolol on sleep behaviour were observed in the objective and subjective measures. There was more frequent awakening during the night with the subjective complaint of difficulties in sleeping through. 4. From this study it is concluded that cilazapril has no major effect on memory functions and sleep behaviour. This is only true for the dosages given and under steady-state conditions.

Health consequences of acute and chronic marihuana use

Chemical content, assay procedures, and pharmacokinetics of cannabis sativa are discussed briefly. Cannabinoid cellular effects relating to chromosomes and immunity including cellular metabolism and allergic reactions are presented. Gross and microscopic brain pathology due to cannabis use is reviewed involving EEG alterations, psychopathology including aggressive behaviour as well as properties of psychomotor impairment, tolerance and dependence. Cardiopulmonary effects of marihuana are recorded under pulmonary pharmacological effects including the macrophage defense system and effects of smoke constituents; under cardiovascular effects cardiac toxicity and possible mechanism of action are discussed. Alterations of reproductive hormonal production and maturation of reproductive cells by marihuana in males and females with attendant impairment of reproductive function or fertility including reproductive outcome are reported. Field studies with healthy chronic cannabis users in Jamaica, Greece and Costa Rica are related as to observed medical alterations. Potential clinical effects are summarized in point form.

The seed and the soil: effect of dosage, personality and starting state on the response to delta 9 tetrahydrocannabinol in man

1 The effects of two doses of delta 9THC (2.5 and 10 mg), delivered by paced smoking of herbal cigarettes, on CNV magnitude, subjective mood ratings and heart rate were studied in 20 subjects. 2 There were highly significant interactions between drug dosage and Extraversion and Neuroticism scores, so that the direction and degree of response to the different doses of delta 9THC depended on the personality characteristics of the subjects. 3 The effects of 9 mg delta 9THC and placebo, delivered in herbal cigarettes smoked naturally, on smoking behaviour, subjective mood ratings, measures of autonomic activity and auditory and visual cortical evoked responses were compared in 12 subjects. 4 Smoking behaviour, subjective 'high' rating and elevation of heart rates were the most significant discriminators between drug and placebo. The latency of some of the components of the visual evoked responses was also increased by delta 9THC. 5 There was a significant correlation between the effects of delta 9THC on skin conductance reactivity and the basal (pre-drug) level, reactivity increasing after drug in subjects with low basal reactivity and decreasing in those with high basal levels. 6 Both experiments provided clear evidence of dose-dependent biphasic stimulant and depressant actions of delta 9THC on both subjective and objective measures, and these effects were influenced by the personality and the starting state of the subjects.

Dissociation of autonomic and cognitive effects of THC in man

Intravenous THC, 30--44.8 microgram/kg, was administered to four subjects. Each received THC on four occasions preceded by either i.v. saline, 0.04 mg/kg atropine sulfate, 0.2 mg/kg propranolol, or both drugs together. Heart rates, subjective intoxication and symptom ratings, time productions, and EEG activity were measured. In the absence of autonomic blocking drugs, THC produced characteristic tachycardia, subjective intoxication, and EEG effects. After combined autonomic blockade, THC had no effect on heart rate, while subjective and EEG changes remained as intense. These findings argue against the hypothesis that the subjective and EEG effects of THC are mediated by autonomic receptors or by interoception of peripheral autonomic actions of THC.