Intractable nausea and vomiting due to gastrointestinal mucosal metastases relieved by tetrahydrocannabinol (dronabinol)

The potential for medicinal cannabis to help manage challenging behaviour in people with intellectual disability: A perspective review

BACKGROUND

Around 2% of the population have intellectual disabilities. Over one-third people with intellectual disabilities (PwID) present with 'challenging behaviour', which nosologically and diagnostically is an abstract concept. Challenging behaviour is influenced by a range of bio-psycho-social factors in a population, which is unable to suitably comprehend and/or communicate concerns. This predisposes to poor health and social outcomes. There is no evidence-based treatments for managing challenging behaviour. Cannabidiol (CBD) and tetrahydrocannabinol (THC) are being trialled for a range of disorders, which are over-represented in PwID and provoke challenging behaviours, such as severe epilepsy, spasticity, post-traumatic stress disorder, social phobia, pain, etc.

METHODS

This perspective review explores the different conditions, which benefit from medicinal CBD/THC preparations, by analysing recent literature from neurobiological, pre-clinical and clinical studies related to the topic. The evidence is synthesised to build an argument of the therapeutic benefits and challenges of medicinal cannabis to manage severe challenging behaviour in PwID.

RESULTS

There is developing evidence of medicinal CBD/THC improving psychiatric and behavioural presentations in general. In particular, there is emergent proof in certain key areas of influence of medicinal CBD/THC positively supporting challenging behaviour, for example in children with neurodevelopmental disorders. However, there are significant challenges in employing such treatments in vulnerable populations such as PwID.

CONCLUSION

Further clinical research for the considered use of medicinal CBD/THC for challenging behaviour management in PwID is needed. Strong co-production with experts with lived experience is needed for further testing to be done in this exciting new area.

Cannabinoids in Medicine: A Multifaceted Exploration of Types, Therapeutic Applications, and Emerging Opportunities in Neurodegenerative Diseases and Cancer Therapy

In this review article, we embark on a thorough exploration of cannabinoids, compounds that have garnered considerable attention for their potential therapeutic applications. Initially, this article delves into the fundamental background of cannabinoids, emphasizing the role of endogenous cannabinoids in the human body and outlining their significance in studying neurodegenerative diseases and cancer. Building on this foundation, this article categorizes cannabinoids into three main types: phytocannabinoids (plant-derived cannabinoids), endocannabinoids (naturally occurring in the body), and synthetic cannabinoids (laboratory-produced cannabinoids). The intricate mechanisms through which these compounds interact with cannabinoid receptors and signaling pathways are elucidated. A comprehensive overview of cannabinoid pharmacology follows, highlighting their absorption, distribution, metabolism, and excretion, as well as their pharmacokinetic and pharmacodynamic properties. Special emphasis is placed on the role of cannabinoids in neurodegenerative diseases, showcasing their potential benefits in conditions such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and multiple sclerosis. The potential antitumor properties of cannabinoids are also investigated, exploring their potential therapeutic applications in cancer treatment and the mechanisms underlying their anticancer effects. Clinical aspects are thoroughly discussed, from the viability of cannabinoids as therapeutic agents to current clinical trials, safety considerations, and the adverse effects observed. This review culminates in a discussion of promising future research avenues and the broader implications for cannabinoid-based therapies, concluding with a reflection on the immense potential of cannabinoids in modern medicine.

Cannabis in Palliative Care: A Systematic Review of Current Evidence

CONTEXT

Palliative care aims to improve the quality of life in patients with incurable illness. Medicinal cannabis (MC) has been used in the palliative care setting to address multiple symptoms in patients.

OBJECTIVES

To evaluate the full scope of available literature investigating the effects and potential harms of MC on symptom management and quality of life in palliative care.

METHODS

PubMed, Embase, The Cochrane Library and clinicaltrials.gov were searched for eligible articles, published between 1960 and September 9, 2021. Quality of the evidence was assessed in accordance with Grading of Recommendations, Assessment, Development and Evaluations. Risk of bias was assessed using the RoB 2 tool for randomised controlled trials and the Risk of Bias in Non-randomized Studies-of Interventions (ROBINS-I) tool for non-randomized trials.

RESULTS

Fifty-two studies (20 randomised; 32 non-randomised) with 4786 participants diagnosed with cancer (n = 4491), dementia (n = 43), AIDS (n = 235), spasticity (n = 16), NORSE syndrome (n = 1) were included. The quality of evidence was 'very low' or 'low' for all studies, and low for only two randomised controlled trials. Positive treatment effects (statistical significance with P < 0.05) were seen for some MC products in pain, nausea and vomiting, appetite, sleep, fatigue, chemosensory perception and paraneoplastic night sweats in patients with cancer, appetite and agitation in patients with dementia and appetite, nausea and vomiting in patients with AIDS. Meta-analysis was unable to be performed due to the wide range of cannabis products used and the heterogeneity of the study outcomes.

CONCLUSION

While positive treatment effects have been reported for some MC products in the palliative care setting, further high quality evidence is needed to support recommendations for its use in clinical practice.

The effect of cannabidiol on canine neoplastic cell proliferation and mitogen-activated protein kinase activation during autophagy and apoptosis

Low tetrahydrocannabinol Cannabis sativa products, also known as hemp products, have become widely available and their use in veterinary patients has become increasingly popular. Despite prevalence of use, the veterinary literature is lacking and evidence-based resource for cannabinoid efficacy. The most prevailing cannabinoid found in hemp is cannabidiolic acid (CBDA) and becomes cannabidiol (CBD) during heat extraction; CBD has been studied for its direct anti-neoplastic properties alone and in combination with standard cancer therapies, yielding encouraging results. The objectives of our study were to explore the anti-proliferative and cell death response associated with in vitro treatment of canine cancer cell lines with CBD alone and combination with common chemotherapeutics, as well as investigation into major proliferative pathways (eg, p38, JNK, AKT and mTOR) potentially involved in the response to treatment with CBD. CBD significantly reduced canine cancer cell proliferation far better than CBDA across five canine neoplastic cell lines when treated with concentrations ranging from 2.5 to 10 μg/mL. Combinatory treatment with CBD and vincristine reduced cell proliferation in a synergistic or additive manner at anti-proliferative concentrations with less clear results using doxorubicin in combination with CBD. The cellular signalling effects of CBD treatment, showed that autophagy supervened induction of apoptosis and may be related to prompt induction of ERK and JNK phosphorylation prior to autophagy. In conclusion, CBD is effective at hindering cell proliferation and induction of autophagy and apoptosis rapidly across neoplastic cell lines and further clinical trials are needed to understand its efficacy and interactions with traditional chemotherapy.

Pyrazoles as Key Scaffolds for the Development of Fluorine-18-Labeled Radiotracers for Positron Emission Tomography (PET)

The need for increasingly personalized medicine solutions (precision medicine) and quality medical treatments, has led to a growing demand and research for image-guided therapeutic solutions. Positron emission tomography (PET) is a powerful imaging technique that can be established using complementary imaging systems and selective imaging agents—chemical probes or radiotracers—which are drugs labeled with a radionuclide, also called radiopharmaceuticals. PET has two complementary purposes: selective imaging for diagnosis and monitoring of disease progression and response to treatment. The development of selective imaging agents is a growing research area, with a high number of diverse drugs, labeled with different radionuclides, being reported nowadays. This review article is focused on the use of pyrazoles as suitable scaffolds for the development of ¹⁸F-labeled radiotracers for PET imaging. A brief introduction to PET and pyrazoles, as key scaffolds in medicinal chemistry, is presented, followed by a description of the most important [¹⁸F]pyrazole-derived radiotracers (PET tracers) that have been developed in the last 20 years for selective PET imaging, grouped according to their specific targets.

Prevalence of cannabis use has significantly increased in patients with cyclic vomiting syndrome

INTRODUCTION

Cyclic vomiting syndrome (CVS) is a functional gastrointestinal disorder which leads to multiple hospitalizations and causes significant impairment of quality of life. Cannabis use is common in patients with CVS, and there are limited data on the national trends in the prevalence of its use in the United States.

METHODS

We used the National Inpatient Sample (NIS) database from 2005 to 2014 and identified hospitalizations with a primary diagnosis of CVS by utilizing the International Classification of Diseases, 9th revision Clinical Modification (ICD-9 CM) coding system. The primary objective of the study was to analyze the prevalence and trends in cannabis use in CVS patients. We also assessed healthcare resource utilization associated with cannabis use.

RESULTS

A total of 129 090 hospitalizations with a primary diagnosis of CVS were identified and included in the study. In the United States, the overall rate of cannabis use among these patients was 104 per 1000 hospitalizations (N = 13 460). Over the last decade, the prevalence of cannabis use increased by 10-fold, from 2.2% in 2005 to 21.2% in 2014.

CONCLUSION

Our analysis of the national database suggests that nearly 1 in 5 CVS hospitalizations have concurrent cannabis use. This prevalence is significantly rising over the last decade, perhaps due to changing legislation and increased utilization of cannabis. Age younger than 35, male gender, African American and Native American race, personal history of alcohol abuse and tobacco use were some of the strongest predictors of cannabis use.

Nausea and Vomiting: a Palliative Care Imperative

PURPOSE OF REVIEW

This review was undertaken to survey recent literature for research reports and comprehensive clinical reviews addressing the pharmacologic management of nausea and vomiting (N&V) in advanced cancer. The goal was to integrate findings in a comprehensive article that incorporates palliative care concepts into antiemetic treatment.

RECENT FINDINGS

There are few published studies of N&V in advanced cancer; such research may be limited by the multicausal nature of N&V and participant burden to patients with life-limiting disease. Most articles are written by oncologists who also specialize in palliative care, and those addressing adverse effects of drugs used as antiemetics are found in other literature. Articles addressing more novel therapies, like cannabinoids and medical marijuana, are uncommon in the oncology literature. N&V in patients with progressive or advanced cancer is often multicausal. Nausea is more common and persistent, and even mild nausea is bothersome and may cause anxiety or depression. The mechanisms of nausea and vomiting overlap, but different neural pathways constitute the final pathway for each-the brainstem for vomiting and higher brain regions for nausea. Common causes of N&V in advanced cancer include constipation, opioids, and malignant bowel obstruction. About 40% have undetermined causes and may be exacerbated by impaired gastric emptying, chemical imbalances, or other factors. Several drugs that have antiemetic effects and act at different receptors are used to palliate N&V. There is a paucity of research that supports palliative antiemetic choices, and other research is needed to define potential therapeutic strategies that capitalize on differences between nausea and vomiting.

Medicinal Properties of Cannabinoids, Terpenes, and Flavonoids in Cannabis, and Benefits in Migraine, Headache, and Pain: An Update on Current Evidence and Cannabis Science

BACKGROUND

Comprehensive literature reviews of historical perspectives and evidence supporting cannabis/cannabinoids in the treatment of pain, including migraine and headache, with associated neurobiological mechanisms of pain modulation have been well described. Most of the existing literature reports on the cannabinoids Δ⁹ -tetrahydrocannabinol (THC) and cannabidiol (CBD), or cannabis in general. There are many cannabis strains that vary widely in the composition of cannabinoids, terpenes, flavonoids, and other compounds. These components work synergistically to produce wide variations in benefits, side effects, and strain characteristics. Knowledge of the individual medicinal properties of the cannabinoids, terpenes, and flavonoids is necessary to cross-breed strains to obtain optimal standardized synergistic compositions. This will enable targeting individual symptoms and/or diseases, including migraine, headache, and pain.

OBJECTIVE

Review the medical literature for the use of cannabis/cannabinoids in the treatment of migraine, headache, facial pain, and other chronic pain syndromes, and for supporting evidence of a potential role in combatting the opioid epidemic. Review the medical literature involving major and minor cannabinoids, primary and secondary terpenes, and flavonoids that underlie the synergistic entourage effects of cannabis. Summarize the individual medicinal benefits of these substances, including analgesic and anti-inflammatory properties.

CONCLUSION

There is accumulating evidence for various therapeutic benefits of cannabis/cannabinoids, especially in the treatment of pain, which may also apply to the treatment of migraine and headache. There is also supporting evidence that cannabis may assist in opioid detoxification and weaning, thus making it a potential weapon in battling the opioid epidemic. Cannabis science is a rapidly evolving medical sector and industry with increasingly regulated production standards. Further research is anticipated to optimize breeding of strain-specific synergistic ratios of cannabinoids, terpenes, and other phytochemicals for predictable user effects, characteristics, and improved symptom and disease-targeted therapies.

Patterns of medicinal cannabis use, strain analysis, and substitution effect among patients with migraine, headache, arthritis, and chronic pain in a medicinal cannabis cohort

BACKGROUND

Medicinal cannabis registries typically report pain as the most common reason for use. It would be clinically useful to identify patterns of cannabis treatment in migraine and headache, as compared to arthritis and chronic pain, and to analyze preferred cannabis strains, biochemical profiles, and prescription medication substitutions with cannabis.

METHODS

Via electronic survey in medicinal cannabis patients with headache, arthritis, and chronic pain, demographics and patterns of cannabis use including methods, frequency, quantity, preferred strains, cannabinoid and terpene profiles, and prescription substitutions were recorded. Cannabis use for migraine among headache patients was assessed via the ID Migraine™ questionnaire, a validated screen used to predict the probability of migraine.

RESULTS

Of 2032 patients, 21 illnesses were treated with cannabis. Pain syndromes accounted for 42.4% (n = 861) overall; chronic pain 29.4% (n = 598;), arthritis 9.3% (n = 188), and headache 3.7% (n = 75;). Across all 21 illnesses, headache was a symptom treated with cannabis in 24.9% (n = 505). These patients were given the ID Migraine™ questionnaire, with 68% (n = 343) giving 3 "Yes" responses, 20% (n = 102) giving 2 "Yes" responses (97% and 93% probability of migraine, respectively). Therefore, 88% (n = 445) of headache patients were treating probable migraine with cannabis. Hybrid strains were most preferred across all pain subtypes, with "OG Shark" the most preferred strain in the ID Migraine™ and headache groups. Many pain patients substituted prescription medications with cannabis (41.2-59.5%), most commonly opiates/opioids (40.5-72.8%). Prescription substitution in headache patients included opiates/opioids (43.4%), anti-depressant/anti-anxiety (39%), NSAIDs (21%), triptans (8.1%), anti-convulsants (7.7%), muscle relaxers (7%), ergots (0.4%).

CONCLUSIONS

Chronic pain was the most common reason for cannabis use, consistent with most registries. The majority of headache patients treating with cannabis were positive for migraine. Hybrid strains were preferred in ID Migraine™, headache, and most pain groups, with "OG Shark", a high THC (Δ9-tetrahydrocannabinol)/THCA (tetrahydrocannabinolic acid), low CBD (cannabidiol)/CBDA (cannabidiolic acid), strain with predominant terpenes β-caryophyllene and β-myrcene, most preferred in the headache and ID Migraine™ groups. This could reflect the potent analgesic, anti-inflammatory, and anti-emetic properties of THC, with anti-inflammatory and analgesic properties of β-caryophyllene and β-myrcene. Opiates/opioids were most commonly substituted with cannabis. Prospective studies are needed, but results may provide early insight into optimizing crossbred cannabis strains, synergistic biochemical profiles, dosing, and patterns of use in the treatment of headache, migraine, and chronic pain syndromes.

Analysis of natural product regulation of cannabinoid receptors in the treatment of human disease

The organized, tightly regulated signaling relays engaged by the cannabinoid receptors (CBs) and their ligands, G proteins and other effectors, together constitute the endocannabinoid system (ECS). This system governs many biological functions including cell proliferation, regulation of ion transport and neuronal messaging. This review will firstly examine the physiology of the ECS, briefly discussing some anomalies in the relay of the ECS signaling as these are consequently linked to maladies of global concern including neurological disorders, cardiovascular disease and cancer. While endogenous ligands are crucial for dispatching messages through the ECS, there are also commonalities in binding affinities with copious exogenous ligands, both natural and synthetic. Therefore, this review provides a comparative analysis of both types of exogenous ligands with emphasis on natural products given their putative safer efficacy and the role of Δ9-tetrahydrocannabinol (Δ9-THC) in uncovering the ECS. Efficacy is congruent to both types of compounds but noteworthy is the effect of a combination therapy to achieve efficacy without unideal side-effects. An example is Sativex that displayed promise in treating Huntington's disease (HD) in preclinical models allowing for its transition to current clinical investigation. Despite the in vitro and preclinical efficacy of Δ9-THC to treat neurodegenerative ailments, its psychotropic effects limit its clinical applicability to treating feeding disorders. We therefore propose further investigation of other compounds and their combinations such as the triterpene, α,β-amyrin that exhibited greater binding affinity to CB₁ than CB₂ and was more potent than Δ9-THC and the N-alkylamides that exhibited CB₂ selective affinity; the latter can be explored towards peripherally exclusive ECS modulation. The synthetic CB₁ antagonist, Rimonabant was pulled from commercial markets for the treatment of diabetes, however its analogue SR144528 maybe an ideal lead molecule towards this end and HU-210 and Org27569 are also promising synthetic small molecules.

Comprehensive Review of Medicinal Marijuana, Cannabinoids, and Therapeutic Implications in Medicine and Headache: What a Long Strange Trip It's Been …

BACKGROUND

The use of cannabis, or marijuana, for medicinal purposes is deeply rooted though history, dating back to ancient times. It once held a prominent position in the history of medicine, recommended by many eminent physicians for numerous diseases, particularly headache and migraine. Through the decades, this plant has taken a fascinating journey from a legal and frequently prescribed status to illegal, driven by political and social factors rather than by science. However, with an abundance of growing support for its multitude of medicinal uses, the misguided stigma of cannabis is fading, and there has been a dramatic push for legalizing medicinal cannabis and research. Almost half of the United States has now legalized medicinal cannabis, several states have legalized recreational use, and others have legalized cannabidiol-only use, which is one of many therapeutic cannabinoids extracted from cannabis. Physicians need to be educated on the history, pharmacology, clinical indications, and proper clinical use of cannabis, as patients will inevitably inquire about it for many diseases, including chronic pain and headache disorders for which there is some intriguing supportive evidence.

OBJECTIVE

To review the history of medicinal cannabis use, discuss the pharmacology and physiology of the endocannabinoid system and cannabis-derived cannabinoids, perform a comprehensive literature review of the clinical uses of medicinal cannabis and cannabinoids with a focus on migraine and other headache disorders, and outline general clinical practice guidelines.

CONCLUSION

The literature suggests that the medicinal use of cannabis may have a therapeutic role for a multitude of diseases, particularly chronic pain disorders including headache. Supporting literature suggests a role for medicinal cannabis and cannabinoids in several types of headache disorders including migraine and cluster headache, although it is primarily limited to case based, anecdotal, or laboratory-based scientific research. Cannabis contains an extensive number of pharmacological and biochemical compounds, of which only a minority are understood, so many potential therapeutic uses likely remain undiscovered. Cannabinoids appear to modulate and interact at many pathways inherent to migraine, triptan mechanisms ofaction, and opiate pathways, suggesting potential synergistic or similar benefits. Modulation of the endocannabinoid system through agonism or antagonism of its receptors, targeting its metabolic pathways, or combining cannabinoids with other analgesics for synergistic effects, may provide the foundation for many new classes of medications. Despite the limited evidence and research suggesting a role for cannabis and cannabinoids in some headache disorders, randomized clinical trials are lacking and necessary for confirmation and further evaluation.

Dronabinol Treatment of Refractory Nausea and Vomiting Related to Peritoneal Carcinomatosis

Nausea and vomiting are common and often highly distressing symptoms in advanced cancer and in hospice and palliative medicine practice. Nausea and vomiting generally respond well to correction of the underlying etiology (when possible) and appropriate selection of antiemetic medication, but up to 7% of patients will have refractory symptoms. Dronabinol is extensively studied for chemotherapy-related nausea and vomiting, but there are only a few case reports of its use in nausea and vomiting unrelated to chemotherapy. We report a patient with end-stage ovarian cancer with peritoneal carcinomatosis and refractory nausea and vomiting who responded dramatically to addition of dronabinol. Dronabinol is usually well tolerated and may have several novel mechanisms of antiemetic action; further study of its scope of efficacy is warranted.

Nausea and vomiting in advanced cancer: the Cleveland Clinic protocol

Nausea and vomiting are common and distressing symptoms in advanced cancer. Both are multifactorial and cause significant morbidity, nutritional failure, and reduced quality of life. Assessment includes a detailed history, physical examination and investigations for reversible causes. Assessment and management will be influenced by performance status, prognosis, and goals of care. Several drug classes are effective with some having the added benefit of multiple routes of administration. It is our institution's practice to recommend metoclopramide as the first drug with haloperidol as an alternative antiemetic. Dexamethasone should be used for patients with central nervous system metastases or bowel obstruction. If your patient is near death, empiric metoclopramide, haloperidol or chlorpromazine is used without further investigation. For patients with a better prognosis, we exclude reversible causes and use the same first-line antiemetics, metoclopramide and haloperidol. For those who do not respond to first-line single antiemetics, olanzapine is second line and ondansetron is third. Rarely do we use combination therapy or cannabinoids. Olanzapine as a single agent has a distinct advantage over antiemetic combinations. It improves compliance, reduces drug interactions and has several routes of administration. Antiemetics, anticholinergics, octreotide and dexamethasone are used in combination to treat bowel obstruction. In opiod-na'ive patients, we prefer haloperidol, glycopyrrolate and an opioid as the first-line treatment and add or substitute octreotide and dexamethasone in those who do not respond. Non-pharmacologic interventions (mechanical stents and percutaneous endoscopic gastrostomy tubes) are used when nausea is refractory to medical management or for home-going management to relieve symptoms, reduce drug costs and rehospitalization.

Nutrition therapy issues in esophageal cancer

Esophageal cancer has traditionally been a disease with poor long term outcomes in terms of both survival and quality of life. In combination with surgical and pharmacologic therapy, nutrition support has been demonstrated to improve patient tolerance of treatment, quality of life, and longterm outcomes. An aggressive multi-disciplinary approach is warranted with nutrition support remaining a cornerstone in management. Historically, nutrition support has focused on adequate caloric provision to prevent weight loss and allow for tolerance of treatment regimens. Alterations in metabolism occur in these patients making their use of available calories inefficient and the future of nutritional support may lie in the ability to alter this deranged metabolism. The purpose of this article is to review the current literature surrounding the etiology, treatment, and role of nutrition support in improving outcomes in esophageal cancer.

[Treatment of nausea and vomiting with 5HT3 receptor antagonists, steroids, antihistamines, anticholinergics, somatostatinantagonists, benzodiazepines and cannabinoids in palliative care patients : a systematic review]

BACKGROUND

Various recommendations exist for the treatment of nausea and vomiting in palliative care but only few studies and even less systematic reviews look into antiemetic therapy for patients receiving palliative care.

OBJECTIVES

This systematic review aims to analyze the current evidence for antiemetic treatment with 5HT3 receptor antagonists, steroids, antihistamines, anticholinergics, somatostatin analogs, benzodiazepines and cannabinoids in palliative care patients with far advanced cancer not receiving chemotherapy or radiotherapy, acquired immune deficiency syndrome (AIDS), chronic obstructive pulmonary disease (COPD), progressive heart failure, amyotrophic lateral sclerosis (ALS) or multiple sclerosis (MS). Results regarding evidence of treatment with prokinetic and neuroleptic agents will be published separately.

METHODS

The electronic databases PubMed and EmBase were systematically searched for studies (published 1966-2011) dealing with antiemetic therapy in palliative care and electronic retrieval was completed by manual searching. Studies with patients undergoing chemotherapy or radiotherapy, pediatric studies and studies published in languages other than English or German were excluded. Studies addressing therapy with 5HT3 receptor antagonists, steroids, antihistamines, anticholinergics, somatostatin analogs, benzodiazepines or cannabinoids were identified and selected for this systematic review.

RESULTS

In the general search 75 relevant studies were found. Of those 36 addressed 5HT3 receptor antagonists, steroids, antihistamines, anticholinergics, somatostatin analogs, benzodiazepines and cannabinoids, 13 considered 5HT3 receptor antagonists, 10 somatostatin antagonists, 9 steroids, 5 cannabinoids, 4 anticholinergics, 1 antihistamines and none benzodiazepines. Furthermore six systematic reviews exist. Evidence for any drug used as an antiemetic is low. Concerning 5HT3 receptor antagonists data are insufficient for recommendations on the treatment of patients with AIDS and MS due to the small size of included patient groups. For patients with cancer contradictory results were published: the larger studies showed a positive effect of 5HT3 receptor antagonists and better efficacy, as compared to metoclopramide, dexamethasone and neuroleptics. Heterogeneous results were found for steroids, with a positive trend for patients with cancer. Data are insufficient for antihistamines. Studies prove effectiveness of butylscopolammonium in the treatment of nausea and vomiting caused by malignant gastrointestinal obstruction, whereas octreotide is superior to butylscopolammonium. Regarding benzodiazepines for symptom control of nausea and vomiting in palliative care patients no studies were detected. Cannabinoids were found to relieve nausea and vomiting in patients with cancer and AIDS but with notable side effects. Furthermore, the studies compared cannabinoids to less recent antiemetic drugs but not, for example to 5HT3 receptor antagonists. Regarding symptom control of nausea and vomiting in patients with COPD, progressive heart failure and ALS no studies were undertaken in patients receiving palliative care.

CONCLUSIONS

In palliative care patients with nausea and vomiting 5HT3 receptor antagonists can be used if treatment with other antiemetics, such as metoclopramide and neuroleptics is not sufficient. There is a trend that steroids in combination with other antiemetics improve symptom relief. Cannabinoids rather have a status as a second line antiemetic. In cases of nausea and vomiting caused by malignant gastrointestinal obstruction octreotide showed the best and butylscopolammonium bromide the second best results. Concerning antihistamines and benzodiazepines insufficient data was found. Recommendations in the literature are mainly based on studies in patients with cancer. The overall strength of evidence is low. More well designed studies in palliative care patients are needed in order to provide evidence-based therapy. The English full text version of this article will be available in SpringerLink as of November 2012 (under "Supplemental").

Nausea and Vomiting in Advanced Cancer

Nausea and vomiting are relatively common in advanced cancer and is dreaded more than pain by patients. The history, pattern of nausea and vomiting, associated symptoms, and physical examination provides clues as to etiology and may guide therapy. Continuous severe nausea unrelieved by vomiting is usually caused by medications or metabolic abnormalities, while nausea relieved by vomiting or induced by eating is usually due to gastroparesis, gastric outlet obstruction, or small bowel obstruction. Drug choices are empiric or based on etiology. Metoclopramide has the greatest evidence for efficacy followed by phenothiazines and tropisetron. Corticosteroids have not been effective in randomized trials except in the case of bowel obstruction. Treatment of nausea unresponsive to first-line medications involves rotation to medications which bind to multiple receptors (broad-spectrum antiemetics), the addition of another antiemetic to a narrow-spectrum antiemetic (a serotonin receptor antagonist such as tropisetron to a phenothiazine), rotation to a different class of antiemetic (tropisetron for a phenothiazine), or in-class drug rotation. Venting gastrostomy, octreotide, and corticosteroids will reduce nausea and vomiting associated with malignant bowel obstruction.

Efficacy of a Scheduled IV Cocktail of Antiemetics for the Palliation of Nausea and Vomiting in a Hospice Population

This is a retrospective analysis of 10 mg metoclopramide, 25 mg diphenhydramine, and 4 mg dexamethasone given intravenous piggyback every 6 hours for nausea or vomiting. Outcome measures were rapidity of symptom relief based on the self-report of the patient and nursing documentation of relief from symptoms of nausea or vomiting. Seven hundred and ninety seven patients were admitted to the inpatient hospice unit during a 2-year period. Sixty-three patients developed nausea or vomiting requiring the cocktail. Fifty-seven patients (90%) had objective response as reflected in nursing notes. Symptom relief was usually noted within 2 days with improvement in oral intake and enjoyment in activities, such as parties and family interactions. Partial relief was noted in patients with gastrointestinal malignancies and peritoneal carcinomatosis even with the addition of other antiemetics to the cocktail.

The novel cannabinoid CB1 receptor neutral antagonist AM4113 suppresses food intake and food-reinforced behavior but does not induce signs of nausea in rats

Drugs that interfere with cannabinoid CB1 transmission suppress various food-motivated behaviors, and it has been suggested that such drugs could be useful as appetite suppressants. Biochemical studies indicate that most of these drugs assessed thus far have been CB1 inverse agonists, and although they have been shown to suppress food intake, they also appear to induce nausea and malaise. The present studies were undertaken to characterize the behavioral effects of AM4113, which is a CB1 neutral antagonist, and to examine whether this drug can reduce food-reinforced behaviors and feeding on diets with varying macronutrient compositions. Biochemical data demonstrated that AM4113 binds to CB1 receptors, but does not show inverse agonist properties (ie no effects on cyclic-AMP production). In tests of spontaneous locomotion and analgesia, AM4113 reversed the effects of the CB1 agonist AM411. AM4113 suppressed food-reinforced operant responding with rats responding on fixed ratio (FR) 1 and 5 schedules of reinforcement in a dose-dependent manner, and also suppressed feeding on high-fat, high-carbohydrate, and lab chow diets. However, in the same dose range that suppressed feeding, AM4113 did not induce conditioned gaping, which is a sign of nausea and food-related malaise in rats. These results suggest that AM4113 may decrease appetite by blocking endogenous cannabinoid tone, and that this drug may be less associated with nausea than CB1 inverse agonists.

[Dronabinol for supportive therapy in patients with malignant melanoma and liver metastases]

BACKGROUND

Loss of appetite and nausea can reduce the quality of life of patients with malignant melanoma and liver metastases. Often established antiemetic drugs fail to bring relief. Tetrahydrocannabinol (THC, Marinol), which is the active agent of Indian hemp, has been used successfully in this situation for other malignant tumors.

PATIENTS AND METHODS

We treated 7 patients with hematogenous metastatic melanoma and liver metastases suffering from extensive loss of appetite and nausea supportively with dronabinol (Marinol. All of these patients had previously received standard antiemetic therapy without adequate relief. Dronabinol is a synthetic Delta-tetrahydrocannabinol. The drug was administered in capsule form. We evaluated the palliative effects of dronabinol with a special patient evaluation form, which was filled out at the beginning of the therapy and again after 4 weeks.

RESULTS

The majority of patients described a significant increase in appetite and decrease in nausea. These effects remained for some weeks, but then decreased as metastases progressed and the general condition worsened. All of the patients experienced slight to moderate dizziness, but it was not sufficiently troubling to cause interruption or termination of therapy.

CONCLUSION

Loss of appetite and nausea due to liver metastases of malignant melanoma can be treated in individual cases supportively with Dronabinol.

Cannabinoid CB1 receptor inverse agonists and neutral antagonists: effects on food intake, food-reinforced behavior and food aversions

Drugs that interfere with cannabinoid CB1 receptor transmission suppress a number of food-related behaviors, and these compounds are currently being assessed for their potential utility as appetite suppressants. In addition to rimonabant (SR141716A), several other compounds have been evaluated, including AM251 and AM1387. Biochemical studies indicate that most of the drugs assessed thus far have been CB1 inverse agonists, and these drugs all act to suppress food intake and disrupt food-reinforced behavior. Behavioral tests involving intake of different diets (i.e., high fat, high carbohydrate, laboratory chow) indicate that consumption of all three food types is disrupted by CB1 inverse agonists, and that, expressed as a percent of baseline intake, the effect is roughly comparable across different diets. Although CB1 inverse agonists do not appear to produce severe motor impairments that disrupt feeding behavior, there is evidence that they can induce nausea and malaise. Recent studies have been undertaken to characterize the behavioral effects of CB1 receptor neutral antagonists such as AM4113 to determine if these drugs can reduce feeding and food-reinforced behaviors. Across a variety of different tests, AM4113 produces effects on food-motivated behavior that are very similar to those produced by CB1 inverse agonists. Moreover, this drug did not induce conditioned gaping in rats or vomiting in ferrets. These results suggest that CB1 receptor neutral antagonists may decrease appetite by blocking endogenous cannabinoid tone, and that these drugs may be less associated with nausea than is the case for CB1 inverse agonists.

Central glucocorticoid receptors modulate the expression of spinal cannabinoid receptors induced by chronic morphine exposure

Central cannabinoid receptors (CBRs) have been implicated in the opioid analgesic effects. However, it remains unclear as to whether the expression of central CBRs would be altered after repeated morphine exposure. Here, we show that chronic intrathecal treatment with morphine (10 microg, twice daily for 6 days) induced a time-dependent upregulation of both CB-1 and CB-2 receptors within the spinal cord dorsal horn. This morphine-induced CB-1 and CB-2 upregulation was dose-dependently attenuated by the intrathecal co-administration of morphine with the glucocorticoid receptor (GR) antagonist RU38486 (0.25, 0.5, or 2 microg). The intrathecal RU38486 treatment regimen also attenuated the development of morphine tolerance. These results indicate that the expression of spinal CBRs was altered following repeated morphine exposure and regulated by the activation of central GRs.

The cannabinoid CB1 antagonist AM 251 produces food avoidance and behaviors associated with nausea but does not impair feeding efficiency in rats

RATIONALE

A growing body of evidence suggests that cannabinoid CB1 receptor antagonists have potential therapeutic utility as appetite suppressants. However, the specific mechanisms underlying the reduction in food intake produced by these drugs are not well understood.

OBJECTIVE

Considering the known antiemetic and motor-suppressive effects of CB1 agonists, the present studies were conducted to determine if the reductions in food intake induced by the CB1 antagonist AM 251 could result from nausea or impairments in intake-related motor control, rather than solely from appetite suppression.

METHODS

Three experiments were conducted to examine the effects of AM 251 (2.0, 4.0, or 8.0 mg/kg or vehicle) on detailed parameters of food intake, on the development of conditioned taste avoidance, and on taste reactivity.

RESULTS

In the first experiment, acute administration of AM 251 dose-dependently decreased food intake; nevertheless, feeding rate (grams consumed per time spent eating) and food handling were unaffected, which suggests that food intake was not reduced because of severe motor impairments. In the second experiment, AM 251 dose-dependently reduced intake of a flavor with which it had previously been associated, indicating that conditioned taste avoidance had developed. Lastly, AM 251 was found to induce conditioned rejection reactions in a dose-dependent manner.

CONCLUSIONS

The CB1 antagonist AM 251 may reduce food intake in part by inducing nausea or malaise, but not because of incoordination or motor slowing related to feeding.

Upregulation of spinal cannabinoid-1-receptors following nerve injury enhances the effects of Win 55,212-2 on neuropathic pain behaviors in rats

Exogenous cannabinoids are effective in attenuating neuropathic pain behaviors induced by peripheral nerve injury, but the mechanisms of their effectiveness remain unclear. Here we examined the expression of spinal cannabinoid-1-receptors (CB1Rs) following chronic constriction sciatic nerve injury (CCI) and its relation to the effects of a CBR agonist (Win 55,212-2) on neuropathic pain in rats. CCI induced a time-dependent upregulation of spinal CB1Rs primarily within the ipsilateral superficial spinal cord dorsal horn as revealed by both Western blot and immunohistochemistry. This CCI-induced CB1R upregulation was at least in part mediated through tyrosine kinase receptors (Trk), because intrathecal treatment with the Trk inhibitor K252a (1 microg) for postoperative days 1-6 significantly reduced the CB1R upregulation in CCI rats. At the intracellular level, the mitogen-activated protein kinase (ERK-MAPK) inhibitor PD98059 (1 microg) prevented, while the protein kinase C inhibitor chelerythrine (10 microg) partially reduced, the CCI-induced CB1R upregulation when each agent was administered intrathecally for postoperative days 1-6. Importantly, the CCI-induced upregulation of spinal CB1Rs enhanced the effects of Win 55,212-2 on both thermal hyperalgesia and mechanical allodynia, since inhibition of the CB1R upregulation by PD98059 resulted in a significant reduction of the effects of Win 55,212-2 in CCI rats. These results indicate that upregulation of spinal CB1Rs following peripheral nerve injury may contribute to the therapeutic effects of exogenous cannabinoids on neuropathic pain.

Orexigenic and anabolic agents

Anorexia and weight loss represent a major cause of morbidity and mortality. At present in the United States two effective anorectic agents are commonly used, namely, megestrol acetate and dronabinol. These two agents are compared in Table 1. In persons with a large excess cytokine production. megestrol acetate should be tried at a does of 800 mg per day for no longer than 3 months. Megestrol acetate should be administered with testosterone in men. It should be avoided in persons who are bed-bound because of the risk of deep vein thrombosis. Dronabinol should be used for most anorectic patients. Dronabinol should initially be given in a low dose (2.5 mg) in the evening. The dose should be increased to 5 mg per day if no improvement in appetite is seen after 2 to 4 weeks. Dronabinol can be continued indefinitely. It seems to have a particularly good profile for persons with anorexia who are at the end of life. In persons with depression and anorexia. mirtazapine seems to be the antidepressant of choice. In addition, the use of taste enhancers can be considered in persons who complain that the food does not taste good. The appropriate use of anabolic agents in older persons with weight loss is controversial. Certainly all older men who are losing weight should have bioavailable testosterone measured and, if the testosterone level is low, should receive testosterone replacement therapy. Women who are losing weight may benefit from the use of low-dose testosterone (eg, Estratest). Anabolic agents, such as oxandrolone, should be reserved for those who have profound cachexia. An approach to the management of anorexia and weight loss in older persons is given in Fig. 1. Thomas et al have provided a more complex algorithm the management of weight loss in nursing home residents.

Carbon-11 labeled radioligands for imaging brain cannabinoid receptors

Two radioligands, [(11)C] SR149080 and its morpholino analog [(11)C] SR149568, were synthesized by reaction of the respective phenolic precursors with [(11)C] methyl iodide. Both radioligands had appropriate regional brain distribution for cannabinoid receptors in mice with peak target to non-target ratios of 2.2 for [(11)C] SR149080 and 1.6 for [(11)C] SR149568 at 90 and 30 minutes post-injection respectively. The uptake of both tracers was blocked with a 1 mg/kg dose of SR141716A.

Tetrahydrocannabinol and endocannabinoids in feeding and appetite

The physiological control of appetite and satiety, in which numerous neurotransmitters and neuropeptides play a role, is extremely complex. Here we describe the involvement of endocannabinoids in these processes. These endogenous neuromodulators enhance appetite in animals. The same effect is observed in animals and in humans with the psychotropic plant cannabinoid Delta(9)-tetrahydrocannabinol, which is an approved appetite-enhancing drug. The CB(1) cannabinoid receptor antagonist SR141716A blocks the effects on feeding produced by the endocannabinoids. If administered to mice pups, this antagonist blocks suckling. In obese humans, it causes weight reduction. Very little is known about the physiological and biochemical mechanisms involved in the effects of Delta(9)-tetrahydrocannabinol and the cannabinoids in feeding and appetite.

Nutrition in the elderly

It is now well accepted that older persons experience a physiologic anorexia, the anorexia of aging, which is caused by alterations in hedonic qualities of food, fundal compliance, and increased leptin levels. Depression is the most common pathologic cause of weight loss in older persons. Older persons fail to recognize thirst and as such have an increased risk of dehydration. Alterations in brain membrane fatty acids can lead to cognitive impairment in older persons.

Central neurocircuitry associated with emesis

Ingestion of toxin, traumatic events, adverse drug reactions, and motion can all result in nausea and emesis. In addition, cyclic vomiting syndrome is quite prevalent in the pediatric population. Coordination of the various autonomic changes associated with emesis occurs at the level of the medulla oblongata of the hindbrain. Chemosensitive receptors detect emetic agents in the blood and relay this information by means of neurons in the area postrema to the adjacent nucleus tractus solitarius (NTS). Abdominal vagal afferents that detect intestinal luminal contents and gastric tone also terminate in the NTS (gelatinosus, commissural, and medial subnuclei). The NTS is viscerotopically organized into subnuclei that subserve diverse functions related to swallowing (subnucleus centralis), gastric sensation (subnucleus gelatinosus), laryngeal and pharyngeal sensation (intermediate and interstitial NTS), baroreceptor function (medial NTS), and respiration (ventrolateral NTS). Neurons from the NTS project to a central pattern generator (CPG), which coordinates the sequence of behaviors during emesis, as well as directly to diverse populations of neurons in the ventral medulla and hypothalamus. Thus, it is critical to realize that there is not an isolated "vomiting center," but rather groups of loosely organized neurons throughout the medulla that may be activated in sequence by a CPG. The newer antiemetic agents appear to block receptors in the peripheral endings of vagal afferents to reduce "perception" of emetic stimuli and/or act in the dorsal vagal complex. A primary site of action of 5-HT(3)-receptor antagonists is by means of the vagal afferents. Neurokinin-1 receptor (NK(1)R) antagonists are antiemetics, because they act at a site in the dorsal vagal complex. Part of their effectiveness may be the result of inhibition of the NK(1)R on vagal motor neurons to prevent fundic relaxation, which is a prodromal event essential for emesis. Delta(9)-tetrahydrocannabinol (Delta(9)-THC), the major psychoactive component of marijuana, can be therapeutically useful as an antiemetic. The site of action of Delta(9)-THC is on cannabinoid CB1 receptors in the dorsal vagal complex. However, it decreases fundic tone and antral motility. It is not easy to predict the potential antiemetic effects of drugs that alter motility. Although antiemetic drugs are available for management of acute chemotherapeutic-induced emesis, few treatments are effective for delayed emesis or cyclic vomiting syndrome.

Inhibition of small intestinal secretion by cannabinoids is CB1 receptor-mediated in rats

We tested the hypothesis that cannabinoids, acting via a neuronal mechanism of action decrease small intestinal secretion. In vitro electrical stimulation induced ileal secretion in rats, that was attenuated by a cannabinoid receptor agonist, WIN 55212-2, (mesylate(R)-(+)-[2, 3-dihydro-5-methyl-3-[4-morpholino)methyl]pyrrolo-[1,2,3-de]-1, 4-benzoxazin-6-yl](1-naphthyl)methanone) but not its optical isomer WIN 55212-3. The inhibition of secretion induced by WIN 55212-2 was reversed by SR141716A (N-(piperidin-1-yl)-5-(4-chlorophenyl)-1(2, 4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide hydrochloride), a cannabinoid CB1 receptor antagonist. An ileal secretory response stimulated by acetylcholine was unaffected by WIN 55212-2. These findings show that cannabinoids inhibit neurally mediated secretion via cannabinoid CB1 receptors. Thus, cannabinoids may have therapeutic potential for diarrhea unresponsive to available therapies.

Biodistribution of [18F] SR144385 and [18F] SR147963: selective radioligands for positron emission tomographic studies of brain cannabinoid receptors

ABSTRACT. [(18)F] SR144385 and [(18)F] SR147963 were synthesized in a multistep reaction in which fluorine-18 was introduced by nucleophilic halogen displacement on a bromo precursor. The fluorine-18-labeled intermediate was deprotected and coupled with the appropriate alkyl amine to give the final products. Both radioligands had appropriate regional brain distribution for cannabinoid receptors with a target to nontarget ratio of 1.7 for [(18)F] SR147963 and 2.5 for [(18)F] SR144385 at 60 and 90 min postinjection, respectively. The uptake of both tracers was blocked with a 1 mg/kg dose of SR141716A.

Delta9-tetrahydrocannabinol inhibits gastric motility in the rat through cannabinoid CB1 receptors

We investigated involvement of the autonomic nervous system in gastric motor and cardiovascular responses to delta9-tetrahydrocannabinol (delta9-THC) in anesthetized rats. Intravenously administered delta9-THC evoked long-lasting decreases in intragastric pressure and pyloric contractility, bradycardia, and hypotension. The changes in gastric motor function and bradycardia were abolished by vagotomy and ganglionic blockade, whereas spinal cord transection prevented the hypotensive response. Administered intravenously alone, N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-met hyl-1H-pyrazole-3-carboxamide, a putative cannabinoid CB1 receptor antagonist, evoked transient decrease in intragastric pressure, and hypertension that was associated with bradycardia. However, this agent completely blocked the gastric motor and cardiovascular responses to intravenous delta9-THC. Application of delta9-THC to the dorsal surface of the medulla resulted in small and short-lasting decreases in gastric motor and cardiovascular function. We conclude that the decrease in gastric motor function and bradycardia are partially due to an action of delta9-THC in the dorsal medulla and that intact vagal nerves are required. The hypotension was mediated through sympathetic pathways. Both gastric motor and cardiovascular effects of peripherally administered delta9-THC seem to be mediated through cannabinoid CB1 receptors.