Antiemetic effect of intramuscular levonantradol in patients receiving anticancer chemotherapy

Cannabinoids for symptom management in children with cancer: A systematic review and meta-analysis

BACKGROUND

Despite the widespread use of medical cannabis, little is known regarding the safety, efficacy, and dosing of cannabis products in children with cancer. The objective of this study was to systematically appraise the existing published literature for the use of cannabis products in children with cancer.

METHODS

This systematic review, registered with the International Prospective Register of Systematic Reviews (CRD42020187433), searched four databases: MEDLINE, Embase, PsycINFO, and the Cochrane Library. Abstracts and full texts were screened in duplicate. Data on types of cannabis products, doses, formulations, frequencies, routes of administration, indications, and clinical and demographic details as well as reported efficacy outcomes were extracted. Data on cannabinoid-related adverse events were also summarized.

RESULTS

Out of 34,611 identified citations, 19 unique studies with a total of 1927 participants with cancer were included: eight retrospective chart reviews, seven randomized controlled trials, two open-label studies, and two case reports. The included studies reported the use of various cannabis products for the management of symptoms. Cannabinoids were commonly used for the management of chemotherapy-induced nausea and vomiting (11 of 19 [58%]). In controlled studies, somnolence, dizziness, dry mouth, and withdrawal due to adverse events were more commonly associated with the use of cannabinoids. Across all included studies, no serious cannabis-related adverse events were reported.

CONCLUSIONS

Although there is evidence to support the use of cannabis for symptom management, in children with cancer, there is a lack of rigorous evidence to inform the dosing, safety, and efficacy of cannabinoids. Because of the increasing interest in using cannabis, there is an urgent need for more research on medical cannabis in children with cancer.

The Spicy Story of Cannabimimetic Indoles

The Sterling Research Group identified pravadoline as an aminoalkylindole (AAI) non-steroidal anti-inflammatory pain reliever. As drug design progressed, the ability of AAI analogs to block prostaglandin synthesis diminished, and antinociceptive activity was found to result from action at the CB1 cannabinoid receptor, a G-protein-coupled receptor (GPCR) abundant in the brain. Several laboratories applied computational chemistry methods to ultimately conclude that AAI and cannabinoid ligands could overlap within a common binding pocket but that WIN55212-2 primarily utilized steric interactions via aromatic stacking, whereas cannabinoid ligands required some electrostatic interactions, particularly involving the CB1 helix-3 lysine. The Huffman laboratory identified strategies to establish CB2 receptor selectivity among cannabimimetic indoles to avoid their CB1-related adverse effects, thereby stimulating preclinical studies to explore their use as anti-hyperalgesic and anti-allodynic pharmacotherapies. Some AAI analogs activate novel GPCRs referred to as "Alkyl Indole" receptors, and some AAI analogs act at the colchicine-binding site on microtubules. The AAI compounds having the greatest potency to interact with the CB1 receptor have found their way into the market as "Spice" or "K2". The sale of these alleged "herbal products" evades FDA consumer protections for proper labeling and safety as a medicine, as well as DEA scheduling as compounds having no currently accepted medical use and a high potential for abuse. The distribution to the public of potent alkyl indole synthetic cannabimimetic chemicals without regard for consumer safety contrasts with the adherence to regulatory requirements for demonstration of safety that are routinely observed by ethical pharmaceutical companies that market medicines.

Cannabinoid Analgesia as a Potential New Therapeutic Option in the Treatment of Chronic Pain

Objective:

To review the literature concerning the physiology of the endocannabinoid system, current drug development of cannabinoid agonists, and current clinical research on the use of cannabinoid agonists for analgesia.

Data Sources:

Articles were identified through a search of MEDLINE (1966–August 2005) using the key words cannabis, cannabinoid, cannabi*, cannabidiol, nabilone, THC, pain, and analgesia. No search limits were included. Additional references were located through review of the bibliographies of the articles identified.

Study Selection and Data Extraction:

Studies of cannabinoid agonists for treatment of pain were selected and were not limited by pain type or etiology. Studies or reviews using animal models of pain were also included. Articles that related to the physiology and pharmacology of the endocannabinoid system were evaluated.

Data Synthesis:

The discovery of cannabinoid receptors and endogenous ligands for these receptors has led to increased drug development of cannabinoid agonists. New cannabimimetic agents have been associated with fewer systemic adverse effects than delta-9-tetrahydrocannabinol, including recent development of cannabis medicinal extracts for sublingual use (approved in Canada), and have had promising results for analgesia in initial human trials. Several synthetic cannabinoids have also been studied in humans, including 2 cannabinoid agonists available on the international market.

Conclusions:

Cannabinoids provide a potential approach to pain management with a novel therapeutic target and mechanism. Chronic pain often requires a polypharmaceutical approach to management, and cannabinoids are a potential addition to the arsenal of treatment options.

Cannabinoids for nausea and vomiting in adults with cancer receiving chemotherapy

BACKGROUND

Cannabis has a long history of medicinal use. Cannabis-based medications (cannabinoids) are based on its active element, delta-9-tetrahydrocannabinol (THC), and have been approved for medical purposes. Cannabinoids may be a useful therapeutic option for people with chemotherapy-induced nausea and vomiting that respond poorly to commonly used anti-emetic agents (anti-sickness drugs). However, unpleasant adverse effects may limit their widespread use.

OBJECTIVES

To evaluate the effectiveness and tolerability of cannabis-based medications for chemotherapy-induced nausea and vomiting in adults with cancer.

SEARCH METHODS

We identified studies by searching the following electronic databases: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsycINFO and LILACS from inception to January 2015. We also searched reference lists of reviews and included studies. We did not restrict the search by language of publication.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared a cannabis-based medication with either placebo or with a conventional anti-emetic in adults receiving chemotherapy.

DATA COLLECTION AND ANALYSIS

At least two review authors independently conducted eligibility and risk of bias assessment, and extracted data. We grouped studies based on control groups for meta-analyses conducted using random effects. We expressed efficacy and tolerability outcomes as risk ratio (RR) with 95% confidence intervals (CI).

MAIN RESULTS

We included 23 RCTs. Most were of cross-over design, on adults undergoing a variety of chemotherapeutic regimens ranging from moderate to high emetic potential for a variety of cancers. The majority of the studies were at risk of bias due to either lack of allocation concealment or attrition. Trials were conducted between 1975 and 1991. No trials involved comparison with newer anti-emetic drugs such as ondansetron. Comparison with placebo People had more chance of reporting complete absence of vomiting (3 trials; 168 participants; RR 5.7; 95% CI 2.6 to 12.6; low quality evidence) and complete absence of nausea and vomiting (3 trials; 288 participants; RR 2.9; 95% CI 1.8 to 4.7; moderate quality evidence) when they received cannabinoids compared with placebo. The percentage of variability in effect estimates that was due to heterogeneity rather than chance was not important (I(2) = 0% in both analyses).People had more chance of withdrawing due to an adverse event (2 trials; 276 participants; RR 6.9; 95% CI 1.96 to 24; I(2) = 0%; very low quality evidence) and less chance of withdrawing due to lack of efficacy when they received cannabinoids, compared with placebo (1 trial; 228 participants; RR 0.05; 95% CI 0.0 to 0.89; low quality evidence). In addition, people had more chance of 'feeling high' when they received cannabinoids compared with placebo (3 trials; 137 participants; RR 31; 95% CI 6.4 to 152; I(2) = 0%).People reported a preference for cannabinoids rather than placebo (2 trials; 256 participants; RR 4.8; 95% CI 1.7 to 13; low quality evidence). Comparison with other anti-emetics There was no evidence of a difference between cannabinoids and prochlorperazine in the proportion of participants reporting no nausea (5 trials; 258 participants; RR 1.5; 95% CI 0.67 to 3.2; I(2) = 63%; low quality evidence), no vomiting (4 trials; 209 participants; RR 1.11; 95% CI 0.86 to 1.44; I(2) = 0%; moderate quality evidence), or complete absence of nausea and vomiting (4 trials; 414 participants; RR 2.0; 95% CI 0.74 to 5.4; I(2) = 60%; low quality evidence). Sensitivity analysis where the two parallel group trials were pooled after removal of the five cross-over trials showed no difference (RR 1.1; 95% CI 0.70 to 1.7) with no heterogeneity (I(2) = 0%).People had more chance of withdrawing due to an adverse event (5 trials; 664 participants; RR 3.9; 95% CI 1.3 to 12; I(2) = 17%; low quality evidence), due to lack of efficacy (1 trial; 42 participants; RR 3.5; 95% CI 1.4 to 8.9; very low quality evidence) and for any reason (1 trial; 42 participants; RR 3.5; 95% CI 1.4 to 8.9; low quality evidence) when they received cannabinoids compared with prochlorperazine.People had more chance of reporting dizziness (7 trials; 675 participants; RR 2.4; 95% CI 1.8 to 3.1; I(2) = 12%), dysphoria (3 trials; 192 participants; RR 7.2; 95% CI 1.3 to 39; I(2) = 0%), euphoria (2 trials; 280 participants; RR 18; 95% CI 2.4 to 133; I(2) = 0%), 'feeling high' (4 trials; 389 participants; RR 6.2; 95% CI 3.5 to 11; I(2) = 0%) and sedation (8 trials; 947 participants; RR 1.4; 95% CI 1.2 to 1.8; I(2) = 31%), with significantly more participants reporting the incidence of these adverse events with cannabinoids compared with prochlorperazine.People reported a preference for cannabinoids rather than prochlorperazine (7 trials; 695 participants; RR 3.3; 95% CI 2.2 to 4.8; I(2) = 51%; low quality evidence).In comparisons with metoclopramide, domperidone and chlorpromazine, there was weaker evidence, based on fewer trials and participants, for higher incidence of dizziness with cannabinoids.Two trials with 141 participants compared an anti-emetic drug alone with a cannabinoid added to the anti-emetic drug. There was no evidence of differences between groups; however, the majority of the analyses were based on one small trial with few events. Quality of the evidence The trials were generally at low to moderate risk of bias in terms of how they were designed and do not reflect current chemotherapy and anti-emetic treatment regimens. Furthermore, the quality of evidence arising from meta-analyses was graded as low for the majority of the outcomes analysed, indicating that we are not very confident in our ability to say how well the medications worked. Further research is likely to have an important impact on the results.

AUTHORS' CONCLUSIONS

Cannabis-based medications may be useful for treating refractory chemotherapy-induced nausea and vomiting. However, methodological limitations of the trials limit our conclusions and further research reflecting current chemotherapy regimens and newer anti-emetic drugs is likely to modify these conclusions.

Gone to Pot - A Review of the Association between Cannabis and Psychosis

Cannabis is the most commonly used illicit drug worldwide, with ~5 million daily users worldwide. Emerging evidence supports a number of associations between cannabis and psychosis/psychotic disorders, including schizophrenia. These associations-based on case-studies, surveys, epidemiological studies, and experimental studies indicate that cannabinoids can produce acute, transient effects; acute, persistent effects; and delayed, persistent effects that recapitulate the psychopathology and psychophysiology seen in schizophrenia. Acute exposure to both cannabis and synthetic cannabinoids (Spice/K2) can produce a full range of transient psychotomimetic symptoms, cognitive deficits, and psychophysiological abnormalities that bear a striking resemblance to symptoms of schizophrenia. In individuals with an established psychotic disorder, cannabinoids can exacerbate symptoms, trigger relapse, and have negative consequences on the course of the illness. Several factors appear to moderate these associations, including family history, genetic factors, history of childhood abuse, and the age at onset of cannabis use. Exposure to cannabinoids in adolescence confers a higher risk for psychosis outcomes in later life and the risk is dose-related. Individuals with polymorphisms of COMT and AKT1 genes may be at increased risk for psychotic disorders in association with cannabinoids, as are individuals with a family history of psychotic disorders or a history of childhood trauma. The relationship between cannabis and schizophrenia fulfills many but not all of the standard criteria for causality, including temporality, biological gradient, biological plausibility, experimental evidence, consistency, and coherence. At the present time, the evidence indicates that cannabis may be a component cause in the emergence of psychosis, and this warrants serious consideration from the point of view of public health policy.

Medicinal Chemistry Endeavors around the Phytocannabinoids

Over the past 50 years, a considerable research in medicinal chemistry has been carried out around the natural constituents of Cannabis sativa L. Following the identification of Delta9-tetrahydrocannabinol (Delta9-THC) in 1964, critical chemical modifications, e.g., variation of the side chain at C3 and the opening of the tricyclic scaffold, have led to the characterization of potent and cannabinoid receptor subtype-selective ligands. Those ligands that demonstrate high affinity for the cannabinoid receptors and good biological efficacy are still used as powerful pharmacological tools. This review summarizes past as well as recent developments in the structure-activity relationships of phytocannabinoids.

Cannabinoids and Psychosis

Recent epidemiological studies and advances in understanding of brain cannabinoid function have renewed interest in the long-recognized association between cannabinoids and psychosis. This chapter presents evidence supporting and refuting the association between cannabinoids and psychosis. Cannabinoids can induce acute transient psychotic symptoms or an acute psychosis in some individuals. What makes some individuals vulnerable to cannabinoid-related psychosis is unclear. Also clear is that cannabinoids can also exacerbate psychosis in individuals with an established psychotic disorder, and these exacerbations may last beyond the period of intoxication. Less clear is whether cannabis causes a persistent de novo psychosis. The available evidence meets many but not all the criteria for causality, including dose-response, temporality, direction, specificity, and biological plausibility. On the other hand, the large majority of individuals exposed to cannabinoids do not experience psychosis or develop schizophrenia and the rates of schizophrenia have not increased commensurate with the increase in rates of cannabis use. Similar to smoking and lung cancer, it is more likely that cannabis exposure is a component cause that interacts with other factors, for example, genetic risk, to "cause" schizophrenia. Nevertheless, in the absence of known causes of schizophrenia, the role of component causes such as cannabis exposure (exogenous hypothesis) is important and warrants further study. There is also tantalizing evidence from postmortem, neurochemical, and genetic studies suggesting CB1 receptor dysfunction (endogenous hypothesis) in schizophrenia that warrants further investigation. Further work is necessary to identify those factors that place individuals at higher risk for cannabinoid-related psychosis, to identify the biological mechanisms underlying the risks and to further study whether CB1 receptor dysfunction contributes to the pathophysiology of psychotic disorders.

Attenuation of cyclophosphamide-induced taste aversions in mice by prochlorperazine, delta 9-tetrahydrocannabinol, nabilone and levonantradol

A series of experiments were performed with adult CD-1 male mice to evaluate the antiemetic effects of several compounds using the conditioned taste aversion procedure. The antiemetics were administered IP immediately prior to a 30-min conditioning trial in which a novel tasting solution (0.3% saccharin) was presented to the subjects. The emetics, apomorphine and the cancer chemotherapeutic drug cyclophosphamide, were given IP immediately after the conditioning trial at doses that induced taste aversions. Three days later the mice received a two bottle preference test (saccharin vs. water) and the percent saccharin consumed of the total fluid intake was calculated. Doses of the phenothiazine antiemetic prochlorperazine (1 and 3 mg/kg) attenuated the aversions produced by 0.3 and 1.0 mg/kg apomorphine. Doses of drugs currently approved or under clinical investigation as antiemetics in conjunction with cancer chemotherapy, i.e., prochlorperazine (1.0 mg/kg), delta 9-tetrahydrocannabinol (0.3 and 1.0 mg/kg) and nabilone (0.01 and 0.03 mg/kg), significantly attenuated the taste aversions induced by cyclophosphamide. Levonantradol at doses of 0.03 and 0.06 mg/kg, however, did not attenuate cyclophosphamide-induced taste aversions. Conditioned taste aversions produced by emetic drugs warrants investigation as a model for evaluating potential antiemetics.

Dose ranging evaluation of the antiemetic efficacy and toxicity of intramuscular levonantradol in cancer subjects with chemotherapy-induced emesis

A phase II double-blind placebo-controlled, randomized dose-ranging trial was undertaken to determine the antiemetic efficacy and toxicity of the synthetic cannabinoid levonantradol at doses of 0.5, 1.0, 1.5, and 2.0 mg. Intramuscular levonantradol was prophylactically administered in random dosing to 20 subjects with a documented history of refractory emesis due to chemotherapy in advanced cancer. The selected dose was administered prior to the chemotherapy and was serially repeated over 12 hours, and efficacy and toxicity data were evaluated for 24 hours. Significant (P less than 0.01) antiemetic activity over placebo was observed with all doses of levonantradol administered, and a dose-effect response was not observed. Doses up to 2.0 mg were well tolerated, and observed toxicity increased with increased doses and with repeated dosing. Psychomimetic effects were mild and tolerable, and the limiting side effects were somnolence and hypotension.

Randomized crossover study of the antiemetic activity of levonantradol and metoclopramide in cancer patients receiving chemotherapy

In a randomized crossover study 57 cancer patients receiving chemotherapy with high emetic potential were treated with low-dose levonantradol or standard-dose metoclopramide and crossed over to the other antiemetic drug in the next identical chemotherapy cycle. In the 45 patients evaluable for treatment response the antiemetic efficacy of levonantradol was significantly better: 62% had less nausea and 58% less vomiting, as against 11% and 16%, respectively, with metoclopramide. Patient preference for antiemetic treatment was levonantradol in 49% and metoclopramide in 22% of cases. Levonantradol treatment was accompanied by a relatively high incidence of side-effects (71%) compared with metoclopramide (29%). The antiemetic efficacy of each single drug was incomplete in most cases of this trial, and antiemetic combination therapy is recommended for further trials.

[New aspects in the antiemetic therapy of cytostatic drug-induced vomiting]

The present intensification of cancer chemotherapy has resulted in increased toxicity. Nausea and vomiting are often severe and prolonged, rendering a patient unfit for further treatment. This review summarizes the current understanding of the physiology of vomiting and the pharmacology and efficacy of the antiemetics in clinical use. It also discusses new approaches with agents, such as cannobinoids, high-dosage metoclopramide, and high-dosage corticosteroids. The new agents are superior to standard antiemetic drugs as demonstrated in a number of trials.

Double-blind multiple-dose crossover study of the antiemetic effect of intramuscular levonantradol compared to prochlorperazine

Twenty cancer patients who received chemotherapy were entered into a double-blind crossover design antiemetic study comparing 1 mg levonantradol, an investigational synthetic cannabinoid, to 10 mg prochlorperazine. Sixteen patients completed the crossover. For each antiemetic course, four doses of each study medication were given intramuscularly 2 hours before chemotherapy and then 2, 6, and 10 hours after chemotherapy administration. There were no statistical differences in patients' responses to levonantradol and prochlorperazine. The frequency of side effects was greater with levonantradol than with prochlorperazine. The most common side effect of levonantradol were somnolence, dry mouth, dizziness, tachycardia, postural hypotension, and blurred vision, while those for prochlorperazine were somnolence, dry mouth, and tachycardia.

Levonantradol for chemotherapy-induced emesis: phase I-II oral administration

Thirty five patients were enrolled into a Phase I-II study of oral levonantradol being tested as an antiemetic for chemotherapy patients who were refractory to the aggressive use of standard antiemetic agents. Sixty-nine total courses were given. Dysphoric reactions (fear, anxiety, hallucinations) were the most serious side effects, and were most prevalent at the highest dose tested (2.0 mg q4h). Somnolence, a "high" feeling, hypotension were also noted. Antiemetic responses were seen at 0.5, 1.0, 1.5 and 2.0 mg dose levels: the two intermediate doses gave responses comparable to those previously reported for oral THC. It is suggested that a combination of oral and parenteral levonantradol may prove to be a very effective program to relieve the otherwise disabling problems of persistent nausea and vomiting.

Levonantradol: a role for central prostanoid mechanisms?

Although delta 9-tetrahydrocannabinol (THC) possesses many pharmacologic activities, attempts to define sites of biochemical action for the natural cannabinoids have been hampered by their low solubility, their low potency, and their relative lack of biologic selectivity. We have recently described a potent, cannabinoid-related analgetic, levonantradol, which acts stereospecifically in animals to produce analgesia qualitatively similar to morphine but at 1/9 to 1/34 the dose. While levonantradol does not act at or through the opiate receptor, the finding of one-way cross tolerance in animals suggests that morphine and levonantradol influence common nociceptive pathways. This report describes a striking structural homology between PGE1 and levonantradol as elucidated by x-ray and conformational studies. This observation is consistent with the generally recognized involvement of prostaglandins in pain and emesis and may have relevance to the site of levonantradol's analgetic actions. More importantly, it provides an ongoing, heuristic basis for exploring, in depth, the role of prostaglandins in the action of levonantradol and cannabinoids.

The effects of levonantradol hydrochloride on tumor growth and therapy

The effects of levonantradol on tumor growth, both directly and in combination with the cytotoxic agent cyclophosphamide, were determined. Levonantradol hydrochloride administered alone had no effect on the progression of either murine sarcoma 180J or leukemia L-1210. Likewise, the increased survival obtained in both tumor systems with cyclophosphamide was not altered by concurrent administration of levonantradol hydrochloride. Levonantradol did not affect the incidence or extent of artificial melanotic lung metastases, nor did it modify lymphoreticular cell stimulation. These data support the use of levonantradol in conjunction with chemotherapy in cancer patients.