Separate and combined effects of the cannabinoid agonists nabilone and Δ9-THC in humans discriminating Δ9-THC

“Background

Agonist replacement treatment is a promising strategy to manage cannabis-use disorders. The aim of this study was to assess the combined effects of the synthetic cannabinoid agonist nabilone and Δ9-tetrahydrocannabinol (Δ9-THC) using drug-discrimination procedures, which are sensitive to drug interactions. Testing the concurrent administration of nabilone and Δ9-THC was also conducted to provide initial safety and tolerability data, which is important because cannabis users will likely lapse during treatment.”

“Conclusions

These results replicate a previous study demonstrating that nabilone shares agonist effects with the active constituent of cannabis in cannabis users, and contribute further by indicating that nabilone would likely be safe and well tolerated when combined with cannabis. These data support the conduct of future studies to determine if nabilone treatment would produce cross-tolerance to the abuse-related effects of cannabis and reduce cannabis use.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3089804/

Recent advantages in cannabinoid research.

Abstract

“Although the active component of cannabis Delta9-THC was isolated by our group 35 years ago, until recently its mode of action remained obscure. In the last decade it was established that Delta9-THC acts through specific receptors – CB1 and CB2 – and mimics the physiological activity of endogenous cannabinoids of two types, the best known representatives being arachidonoylethanolamide (anandamide) and 2-arachidonoylglycerol (2-AG). THC is officially used against vomiting caused by cancer chemotherapy and for enhancing appetite, particularly in AIDS patients. Illegally, usually by smoking marijuana, it is used for ameliorating the symptoms of multiple sclerosis, against pain, and in a variety of other diseases. A synthetic cannabinoid, HU-211, is in advanced clinical tests against brain damage caused by closed head injury. It may prove to be valuable against stroke and other neurological diseases.”

http://www.ncbi.nlm.nih.gov/pubmed/10575284

Central and peripheral mechanisms contribute to the antiemetic actions of delta-9-tetrahydrocannabinol against 5-hydroxytryptophan-induced emesis.

Abstract

“Delta-9-tetrahydrocannabinol (delta-9-THC) prevents cisplatin-induced emesis via cannabinoid CB(1) receptors. Whether central and/or peripheral cannabinoid CB(1) receptors account for the antiemetic action(s) of delta-9-THC remains to be investigated. The 5-hydroxytryptamine (5-HT=serotonin) precursor, 5-hydroxytryptophan (5-HTP), is an indirect 5-HT agonist and simultaneously produces the head-twitch response (a centrally mediated serotonin 5-HT(2A) receptor-induced behavior) and emesis (a serotonin 5-HT(3) receptor-induced response, mediated by both peripheral and central mechanisms) in the least shrew (Cryptotis parva). The peripheral amino acid decarboxylase inhibitor, carbidopa, prevents the conversion of 5-HTP to 5-HT in the periphery and elevates 5-HTP levels in the central nervous system (CNS). When administered i.p. alone, a 50 mg/kg dose of 5-HTP failed to induce either behaviour while its 100 mg/kg dose produced robust frequencies of both head-twitch response and emesis. Pretreatment with carbidopa (0, 10, 20 and 40 mg/kg) potentiated the ability of both doses of 5-HTP to produce the head-twitch response in a dose-dependent but bell-shaped manner, with maximal potentiation occurring at 20 mg/kg carbidopa. Carbidopa dose-dependently reduced the frequency of 5-HTP (100 mg/kg)-induced emesis, whereas the 10 mg/kg dose potentiated, and the 20 and 40 mg/kg doses suppressed the frequency of vomits produced by the 50 mg/kg dose of 5-HTP. The peripheral and/or central antiemetic action(s) of delta-9-THC (0, 1, 2.5, 5, 10 and 20 mg/kg) against 5-HTP (100 mg/kg)-induced head-twitch response and emesis were investigated in different groups of carbidopa (0, 10 and 20 mg/kg) pretreated shrews. Irrespective of carbidopa treatment, delta-9-THC attenuated the frequency of 5-HTP-induced head-twitch response in a dose-dependent manner with similar ID(50) values. Although delta-9-THC also reduced the frequency of 5-HTP-induced emesis with similar ID(50s), at the 5 mg/kg delta-9-THC dose however, 5-HTP induced significantly less vomits in the 10 and 20 mg/kg carbidopa-treated groups relative to its 0 mg/kg control group. Moreover, increasing doses of carbidopa significantly shifted the inhibitory dose-response effect of delta-9-THC in protecting shrews from 5-HTP-induced emesis to the left. Relatively, a large dose of delta-9-THC (20 mg/kg) was required to significantly reduce the number of vomits produced by direct acting serotonergic 5-HT(3) receptor agonists, serotonin and 2-methylserotonin. Low doses of delta-9-THC (0.1-1 mg/kg) nearly completely prevented 2-methylserotonin-induced, centrally mediated, head-twitch and ear-scratch responses. The results indicate that delta-9-THC probably acts pre- and postsynaptically to attenuate emesis produced by indirect and direct acting 5-HT(3) receptor agonists via both central and peripheral mechanisms. In addition, delta-9-THC prevents 5-HTP-induced head-twitch and emesis via cannabinoid CB(1) receptors since the CB(1) receptor antagonist, SR 141716A [N-piperidino-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methylpyrazole-3-carboxamide], countered the inhibitory actions of an effective dose of delta-9-THC against both behaviours.”

http://www.ncbi.nlm.nih.gov/pubmed/15044052

http://www.thctotalhealthcare.com/category/nauseavomiting/

Delta-9-tetrahydrocannabinol differentially suppresses cisplatin-induced emesis and indices of motor function via cannabinoid CB(1) receptors in the least shrew.

“The present study investigates the cannabinoid receptor mechanisms by which Delta(9)-THC produces its antiemetic effects against cisplatin -induced emesis as well as its cannabimimetic activity profile (motor reduction) in the least shrew.

Intraperitoneal administration of Delta(9)-THC (1, 2.5, 5 and 10 mg/kg) dose-dependently reduced both the percentage of animals vomiting (ID(50)=1.8+/-1.6 mg/kg) and the frequency of vomits (ID(50)=0.36+/-1.18 mg/kg) in a potent manner.

The lowest significantly effective antiemetic dose of Delta(9)-THC for the latter emesis parameters was 2.5 mg/kg. Although Delta(9)-THC reduced the frequency of vomits up to 98%, it failed to completely protect all tested shrews from vomiting (80% protection). The cannabinoid CB(1) antagonist (SR 141716A) and not the CB(2) antagonist (SR 144528), reversed the antiemetic effects of Delta(9)-THC in a dose-dependent fashion. Delta(9)-THC (1, 5, 10 and 20 mg/kg, ip) suppressed locomotor parameters (spontaneous locomotor activity, duration of movement and rearing frequency) in a biphasic manner and only the 20-mg/kg dose simultaneously suppressed the triad of locomotor parameters to a significant degree. Subcutaneous (1-10 mg/kg) and intraperitoneal (0.05-40 mg/kg) injection of some doses of SR 141716A caused significant reductions in one or more components of the triad of locomotor parameters but these reductions were not dose dependent. Subcutaneous injection of SR 141716A (0.2, 1, 5 and 10 mg/kg) reversed the motor suppressant effects of a 20-mg/kg dose of Delta(9)-THC (ip) in a dose-dependent manner. Relative to its motor suppressant effects,

Delta(9)-THC is a more potent antiemetic agent. Both effects are probably mediated via CB(1) receptors in distinct loci.”

http://www.ncbi.nlm.nih.gov/pubmed/11420092

http://www.thctotalhealthcare.com/category/nauseavomiting/

Antiemetic and motor-depressive actions of CP55,940: cannabinoid CB1 receptor characterization, distribution, and G-protein activation.

Abstract

“Dibenzopyran (Delta(9)-tetrahydrocannabinol) and aminoalkylindole [R(+)-[2,3-dihydro-5-methyl-3-[(morpholinyl)methyl]pyrolol[1,2,3-de]-1,4-benzoxazin-yl]-(1-naphthalenyl) methanone mesylate; (WIN55,212-2)] cannabinoids suppress vomiting produced by cisplatin via cannabinoid CB(1) receptors. This study investigates the antiemetic potential of the “nonclassical” cannabinoid CP55,940 [1alpha,2beta-(R)-5alpha]-(-)-5-(1,1-dimethyl)-2-[5-hydroxy-2-(3-hydroxypropyl) cyclohexyl-phenol] against cisplatin-induced vomiting and assesses the presence and functionality of cannabinoid CB(1) receptors in the least shrew (Cryptotis parva) brain. CP55,940 (0.025-0.3 mg/kg) reduced both the frequency of cisplatin-induced emesis (ID(50)=0.025 mg/kg) and the percentage of shrews vomiting (ID(50)=0.09 mg/kg). CP55,940 also suppressed shrew motor behaviors (ID(50)=0.06- 0.21 mg/kg) at such doses. The antiemetic and motor-suppressant actions of CP55,940 were countered by SR141716A [N-piperidino-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methylpyrazole-3-carboxamide], indicating both effects are cannabinoid CB(1) receptor-mediated. Autoradiographic studies with [3H]-SR141716A and [35S]-GTPgammaS binding revealed that the distribution of the cannabinoid CB(1) receptor and its activation pattern are similar to rodent brain and significant levels are present in brain loci (e.g., nucleus tractus solitarius (NTS)) that control emesis. The affinity rank order of structurally diverse cannabinoid ligands for cannabinoid CB(1) receptor in shrew brain is similar to rodent brain: HU-210=CP55,940=SR141716A>/=WIN55,212-2>/=delta-9-tetrahydrocannabinol>methanandamide=HU-211=cannabidiol=2-arachidonoylglycerol. This affinity order is also similar and is highly correlated to the cannabinoid EC(50) potency rank order for GTPgammaS stimulation except WIN55,212-2 and delta-9-tetrahydrocannabinol potency order were reversed. The affinity and the potency rank order of tested cannabinoids were significantly correlated with their antiemetic ID(50) potency order against cisplatin-induced vomiting (CP55,940>WIN55,212-2=delta-9-tetrahydrocannabinol) as well as emesis produced by 2-arachidonoylglycerol or SR141716A (CP55,940>WIN55,212-2>delta-9-tetrahydrocannabinol).”

http://www.ncbi.nlm.nih.gov/pubmed/12505537

Antiemetic efficacy of levonantradol compared to delta-9-tetrahydrocannabinol for chemotherapy-induced nausea and vomiting.

Abstract

“The antiemetic efficacy of im levonantradol, a synthetic cannabinoid, given at a dose of 1 mg every 4 hours, was compared to oral delta-9-tetrahydrocannabinol (THC) given at a dose of 15 mg every 4 hours in a double-blind crossover study. Twenty-six patients receiving emetogenic cancer chemotherapy were evaluated. For each drug, 28% of treated patients had no nausea. The median number of emetic episodes with levonantradol was 2.0 versus 3.0 for THC (P = 0.06). Side effects occurred in 91.7% and 97.3% of levonantradol and THC patients, respectively, with drowsiness and dizziness most commonly seen. Side effects were generally well-tolerated, with only 13.9% of levonantradol and 21.6% of THC patients discontinuing treatment because of side effects. Levonantradol appears to be at least as effective an antiemetic as THC and is the only cannabinoid available for parenteral use.”

http://www.ncbi.nlm.nih.gov/pubmed/2981616

Delta-9-tetrahydrocannabinol in cancer chemotherapy: research problems and issues.

Abstract

“A critical review of the literature assessing the antiemetic efficacy of delta-9-tetrahydrocannabinol (THC) in patients receiving cancer chemotherapy showed considerable inconsistency in results. The equivocal nature of these results partly reflects the difficulty of doing research on antiemetic therapies, but also can be attributed to differences in the adequacy and nature of the research designs, procedures, and assessment instruments that have been used. Several factors were also identified that are seldom studied but may be important in determining whether THC will be effective: patient variables, such as chemotherapy regimen and age; pharmacologic variables, such as drug tolerance, dose, schedule, toxicity, route of administration, and drug interactions; and environmental variables associated with administration setting. The need to differentiate pharmacologically induced from conditioned nausea and vomiting was also pointed out. We believe that THC does have antiemetic efficacy, but the lack of controlled research does not allow precise knowledge of its true effectiveness and toxicity. Well-controlled trials are needed to help answer some of these questions.”

http://www.ncbi.nlm.nih.gov/pubmed/6305249

Amelioration of cancer chemotherapy-induced nausea and vomiting by delta-9-tetrahydrocannabinol.

Abstract

“The antinausea and antivomiting effects of delta-9-tetrahydrocannabinol (THC) in children receiving cancer chemotherapy were compared with those of metoclopramide syrup and prochlorperazine tablets in two double-blind studies. THC was found to be a significantly better antinausea and antivomiting agent… In some patients, THC enhanced appetite during a course of chemotherapy. In two patients, a “high” associated with THC administrationwas reported. Drowsiness was reported significantly more frequently with THC.”

http://www.ncbi.nlm.nih.gov/pubmed/231736

Preliminary efficacy and safety of an oromucosal standardized cannabis extract in chemotherapy-induced nausea and vomiting

  “Despite progress in anti-emetic treatment, many patients still suffer from chemotherapy-induced nausea and vomiting (CINV). This is a pilot, randomized, double-blind, placebo-controlled phase II clinical trial designed to evaluate the tolerability, preliminary efficacy, and pharmacokinetics of an acute dose titration of a whole-plant cannabis-based medicine (CBM) containing delta-9-tetrahydrocannabinol and cannabidiol, taken in conjunction with standard therapies in the control of CINV.”

“Compared with placebo, CBM added to standard antiemetic therapy was well tolerated and provided better protection against delayed CINV. These results should be confirmed in a phase III clinical trial.”

“A systematic review of 30 clinical trials involving orally administered synthetic cannabinoids (nabilone and dronabinol) showed that they were superior to dopamine receptor antagonists in preventing CINV. Both are approved by the US Food and Drug Administration for use in CINV refractory to conventional anti-emetic therapy, but some authors have questioned the appropriateness of orally administered cannabinoids due to the variability in their gastrointestinal absorption, low bioavailability, long half-lives and the difficulties for an adequate self titration of the dose.”

“Animal studies suggest that the combined administration of different cannabinoids may enhance some of the therapeutic effects of delta-9-tetrahydrocannabinol (THC). This might explain why some patients preferred marihuana to synthetic cannabinoids in clinical trials.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2997305/

Efficacy of Crude Marijuana and Synthetic Delta-9-Tetrahydrocannabinol as Treatment for Chemotherapy-Induced Nausea and Vomiting: A Systematic Literature Review.

Abstract

“Purpose/Objectives: To synthesize the research to determine whether oral delta-9-tetrahydrocannabinol (THC) and smoked marijuana are effective treatments for chemotherapy-induced nausea and vomiting (CINV) and to evaluate side effects and patient preference of these treatments.Data Sources: Original research, review articles, and other published articles in CINAHL(R), MEDLINE(R), and Cochrane Library databases.Data Synthesis: Cannabinoids are effective in controlling CINV, and oral THC and smoked marijuana have similar efficacy. However, smoked marijuana may not be accessible or safe for all patients with cancer. Also, these drugs have a unique side-effect profile that may include alterations in motor control, dizziness, dysphoria, and decreased concentration.Conclusions: This synthesis shows that cannabinoids are more effective than placebo and comparable to antiemetics such as prochlorperazine and ondansetron for CINV.Implications for Nursing: Nurses should feel supported by the literature to recommend oral synthetic THC as a treatment for CINV to their patients and physician colleagues. Nurses should be cognizant of the side-effect profile for this medication and provide appropriate patient education.”

http://www.ncbi.nlm.nih.gov/pubmed/19596652