Psychomotor performance in relation to acute oral administration of Δ9-tetrahydrocannabinol and standardized cannabis extract in healthy human subjects Cannabinoids in the management of difficult to treat pain FAAH selectively influences placebo effects The Psychotomimetic Effects of Intravenous Delta-9-Tetrahydrocannabinol in Healthy Individuals: Implications for Psychosis Short-Term Effects of Cannabinoids in Patients with HIV-1 Infection Delta-9-tetrahydrocannabinol for nighttime agitation in severe dementia
Abnormalities in psychomotor performance are a consistent finding in schizophrenic patients as well as in chronic cannabis users . The high levels of central cannabinoid ( CB1 ) receptors in the basal ganglia , the cerebral cortex and the cerebellum indicate their implication in the regulation of motor activity . Based on the close relationship between cannabis use , the endogenous cannabinoid system and motor disturbances found in schizophrenia , we expected that administration of cannabinoids may change pattern of psychomotor activity like in schizophrenic patients . This prospect i ve , double-blind , placebo-controlled cross-over study investigated the acute effects of cannabinoids on psychomotor performance in 24 healthy right-h and ed volunteers ( age 27.9 ± 2.9 years , 12 male ) by comparing Δ9-tetrahydrocannabinol ( Δ9-THC ) and st and ardized cannabis extract containing Δ9-THC and cannabidiol .  Psychomotor performance was assessed by using a finger tapping test series . Cannabis extract , but not Δ9-THC , revealed a significant reduction of right-h and tapping frequencies that was also found in schizophrenia . As to the pure Δ9-THC condition , left-h and tapping frequencies were correlated with the plasma concentrations of the Δ9-THC metabolite 11-OH-THC . These effects are thought to be related to cannabinoid actions on CB1 receptors in the basal ganglia , the cerebral cortex and the cerebellum . Our data further demonstrate that acute CB1 receptor activation under the cannabis extract condition may also affect intermanual coordination ( IMC ) as an index of interhemispheric transfer . AIR-Scale scores as a measure of subjective perception of intoxication were dose-dependently related to IMC which was shown by an inverted U-curve . This result may be due to functional changes involving GABAergic and glutamatergic neurotransmission within the corpus callosum This article review s recent research on cannabinoid analgesia via the endocannabinoid system and non-receptor mechanisms , as well as r and omized clinical trials employing cannabinoids in pain treatment .  Tetrahydrocannabinol ( THC , Marinol ® ) and nabilone ( Cesamet ® ) are currently approved in the United States and other countries , but not for pain indications . Other synthetic cannabinoids , such as ajulemic acid , are in development . Crude herbal cannabis remains illegal in most jurisdictions but is also under investigation . Sativex ® , a cannabis derived oromucosal spray containing equal proportions of THC ( partial CB1 receptor agonist ) and cannabidiol ( CBD , a non-euphoriant , anti-inflammatory analgesic with CB1 receptor antagonist and endocannabinoid modulating effects ) was approved in Canada in 2005 for treatment of central neuropathic pain in multiple sclerosis , and in 2007 for intractable cancer pain . Numerous r and omized clinical trials have demonstrated safety and efficacy for Sativex in central and peripheral neuropathic pain , rheumatoid arthritis and cancer pain . An Investigational New Drug application to conduct advanced clinical trials for cancer pain was approved by the US FDA in January 2006 . Cannabinoid analgesics have generally been well tolerated in clinical trials with acceptable adverse event profiles . Their adjunctive addition to the pharmacological armamentarium for treatment of pain shows great promise Endogenous opioid and cannabinoid systems are thought to act synergistically regulating antinociceptive and reward mechanisms . To further underst and the human implication s of the interaction between these two systems , we investigated the role of the common , functional missense variant Pro129Thr of the gene coding fatty acid amide hydrolase ( FAAH ) , the major degrading enzyme of endocannabinoids , on psychophysical and neurotransmitter ( dopaminergic , opioid ) responses to pain and placebo-induced analgesia in humans . FAAH Pro129/Pro129 homozygotes , who constitute nearly half of the population , reported higher placebo analgesia and more positive affective states immediately and 24 h after placebo administration ; no effects on pain report in the absence of placebo were observed . Pro129/Pro129 homozygotes also showed greater placebo-induced μ-opioid , but not D2/3 dopaminergic , enhancements in neurotransmission in regions known involved in placebo effects . These results show that a common genetic variation affecting the function of the cannabinoid system is serving as a probe to demonstrate the involvement of cannabinoid and opioid transmitters on the formation of placebo effects Recent advances in the underst and ing of brain cannabinoid receptor function have renewed interest in the association between cannabinoid compounds and psychosis . In a 3-day , double-blind , r and omized , and counterbalanced study , the behavioral , cognitive , and endocrine effects of 0 , 2.5 , and 5 mg intravenous delta-9-tetrahydrocannabinol ( Δ-9-THC ) were characterized in 22 healthy individuals , who had been exposed to cannabis but had never been diagnosed with a cannabis abuse disorder . Prospect i ve safety data at 1 , 3 , and 6 months post study was also collected . Δ-9-THC ( 1 ) produced schizophrenia-like positive and negative symptoms ; ( 2 ) altered perception ; ( 3 ) increased anxiety ; ( 4 ) produced euphoria ; ( 5 ) disrupted immediate and delayed word recall , sparing recognition recall ; ( 6 ) impaired performance on tests of distractibility , verbal fluency , and working memory ( 7 ) did not impair orientation ; ( 8) increased plasma cortisol . These data indicate that Δ-9-THC produces a broad range of transient symptoms , behaviors , and cognitive deficits in healthy individuals that resemble some aspects of endogenous psychoses . These data warrant further study of whether brain cannabinoid receptor function contributes to the pathophysiology of psychotic disorders Context Because the same systems metabolize cannabinoids and protease inhibitors , cannabinoids might alter viral loads in HIV-infected patients taking protease inhibitors . Contribution In this r and omized trial , 62 HIV-infected patients taking indinavir or nelfinavir  received a marijuana cigarette , dronabinol capsule , or placebo capsule three times daily for 21 days . Half of the patients in all three groups had undetectable viral loads during the study , and average changes in viral load with marijuana and dronabinol , relative to placebo , were small . Caution s The findings of no large harmful effects on viral loads with either smoked or oral cannabinoids need to be confirmed in larger and longer trials . The Editors Marijuana has been smoked for medicinal purpose s for centuries ( 1 ) . Introduced into western medicine in 1842 , marijuana was used to treat various illnesses on the basis of its purported analgesic , anticonvulsant , sedative , hypnotic , and antispasmodic properties . With the passage of the Marihuana Tax Act in 1937 , use of marijuana as a therapeutic agent in the United States waned until the substance was removed from the U.S. Pharmacopoeia in 1942 . The Controlled Substances Act of 1970 placed marijuana in the Schedule I category along with other substances deemed to have no medicinal value and high potential for abuse . In 1986 , the U.S. Food and Drug Administration approved a synthetic , oral form of marijuana 's main psychoactive component , delta-9-tetrahydrocannabinol ( dronabinol , Marinol , Roxane Laboratories , Columbus , Ohio ) , for treating chemotherapy-induced nausea and vomiting ( 2 - 5 ) . A r and omized , controlled trial demonstrated that dronabinol increased self-reported appetite but not weight in patients with AIDS-related wasting syndrome ; these findings led to an expansion of the labeling indication for this use in 1992 ( 6 , 7 ) . Before the advent of highly active antiretroviral therapy in the 1990s , many patients infected with HIV-1 experienced wasting as a preterminal manifestation of the disease ( 8) . Patients with AIDS-related wasting syndrome often reported that they preferred smoked marijuana to dronabinol because it was easier to titrate the dose to achieve the desired effect ; smoked marijuana delivers cannabinoids to the bloodstream much more rapidly than dronabinol ( 9 ) . By the mid-1990s , cannabis buyers ' clubs in the San Francisco Bay area were reportedly selling marijuana to 11 000 patients with HIV infection ( 10 - 12 ) . With the increased availability of protease inhibitorcontaining antiretroviral regimens in the mid-1990s , the incidence of AIDS-related wasting syndrome decreased markedly , as did most of the other late-stage opportunistic manifestations of advanced HIV disease ( 13 - 15 ) . Protease inhibitors , which can inhibit or stimulate the hepatic cytochrome P-450 enzyme system , are subject to many significant drugdrug interactions with other agents used in treating HIV infection and its complications ( 16 , 17 ) . The potential for a drugdrug interaction between protease inhibitors and marijuana is worrisome since many HIV-infected patients continue to smoke marijuana as an appetite stimulant or to decrease nausea associated with their antiretroviral therapy ( 18 , 19 ) . The likelihood of such an interaction is supported by the facts that cannabinoids are metabolized by some of the same cytochrome P-450 enzyme isoforms that metabolize the more widely prescribed protease inhibitors and that tetrahydrocannabinol has been shown to inhibit the metabolism of other drugs ( 20 - 23 ) . Although few recent clinical trials have evaluated the potential therapeutic effects of smoked marijuana , significant progress has been made in underst and ing the pharmacology of cannabinoids in humans . Of the two cannabinoid receptors identified , CB1 ( found mainly in cells of the central nervous system ) is thought to be responsible for the neurologic and behavioral effects of marijuana ( 24 , 25 ) . The identification of a CB2 receptor , found predominantly on B lymphocytes and natural killer cells , suggests that cannabinoids may also affect the immune response . Some studies suggest that marijuana can impair the immune system through B-lymphocyte modulation , tumor necrosis factor inhibition , or changes in the phenotype and function of circulating lymphocytes ( 26 - 29 ) . The hallmark of successful antiretroviral therapy is sustained suppression of HIV RNA levels associated with increasing CD4 + cell counts ( 30 - 32 ) . Considering the potential for both a protease inhibitorcannabinoid interaction and an effect of smoked marijuana on the immune system , we design ed a study to determine the safety or toxicity profile of cannabinoids ( smoked and oral ) in persons with HIV infection . We chose HIV RNA levels as our primary outcome because an intervention that interacted unfavorably with either the antiretroviral agent pharmacokinetics or the immune system directly could cause a perturbation of viral suppression . We report the overall safety results of this r and omized , controlled inpatient clinical trial . Methods Study Group Study participants were recruited by referrals from local physicians and advertisements in newspapers . Volunteers from across the country telephoned to determine whether they might be eligible to participate . Participants were required to be at least 18 years of age , have documented HIV infection , and be receiving a stable antiretroviral treatment regimen of either indinavir ( Crixivan , Merck & Co. , Inc. , North Wales , Pennsylvania ) or nelfinavir ( Viracept , Agouron Pharmaceuticals , Inc. , La Jolla , California ) for at least 8 weeks before enrollment . When enrolled , participants who had been taking the recently recommended dose of nelfinavir  , 1250 mg twice daily , were switched to 750 mg three times daily for consistency of our pharmacokinetic evaluations ( 33 ) . No additional protease inhibitors were allowed for the duration of the study . Participants were also required to have a stable viral load , defined as less than a threefold ( 0.5 log10 ) change in HIV RNA level for the 16 weeks before enrollment . All participants were required to have previous experience smoking marijuana ( defined as six or more times ) to ensure that they knew how to inhale and what neuropsychiatric effects to expect . The institutional review board of the University of California , San Francisco , approved the study , and signed , informed consent was obtained from each participant before enrollment . Exclusion criteria included any active opportunistic infection or malignant condition requiring acute treatment , unintentional loss of 10 % or more of body weight during the previous 6 months , current substance dependence ascertained by completion of a confidential drug screening form and an alcohol screening form , methadone maintenance , use of tobacco or cannabinoids ( smoked or oral ) within 30 days of enrollment , history of serious pulmonary disease , pregnancy , or stage II or higher AIDS dementia complex . Laboratory exclusion criteria were hematocrit less than 0.25 and elevation of hepatic aminotransferase levels to greater than five times the upper limit of normal . Therapeutic exclusions were concurrent use within the past 8 weeks of anabolic hormones , prednisone , interleukin-2 , or other agents known to alter immune system function . Study Medications The National Institute on Drug Abuse provided prerolled marijuana cigarettes , weighing on average 0.9 g and containing 3.95 % delta-9-tetrahydrocannabinol . These cigarettes were kept in a locked and alarmed freezer until they were dispensed to a locked freezer in the General Clinical Research Center at the San Francisco General Hospital , where the inpatient study was conducted . The frozen marijuana cigarettes required rehydration overnight in a humidifier . Participants r and omly assigned to the smoked marijuana group were housed in a room with a fan ventilating to the outside . To maximize st and ardization of inhaled doses , research staff monitored participants while they followed the uniform puff procedure outlined by Foltin and colleagues ( 34 ) . Research staff weighed the marijuana cigarettes immediately before and after they were administered to participants and returned all leftover material to the pharmacy . Study participants smoked up to three complete marijuana cigarettes daily , as tolerated , 1 hour before meals . Study participants were r and omly assigned in a double-blind fashion to the oral regimens , which were given on the same schedule as the smoked marijuana . Research staff observed participants taking all treatments . Research Design and Procedures Study clinicians admitted study participants to the General Clinical Research Center for a 4-day lead-in period to obtain baseline variables . A urine sample obtained on the day of admission ( day 4 ) had to be negative for tetrahydrocannabinol . The second phase of the trial was a 21-day intervention period beginning with r and om assignment of treatments on day 0 . Patients were stratified by protease inhibitor ( indinavir or nelfinavir ) and then allocated with equal probability in blocks of 12 to the study agents ( marijuana , dronabinol , and placebo ) . The statistician generated the r and om allocation sequences , and the pharmacists maintained the sequences in a secure location and distributed the assignments to the study coordinator on day 0 . Study participants were not permitted to have visitors or to leave the General Clinical Research Center unless accompanied by research personnel during the 25-day study . All clinical laboratory tests and study procedures were obtained or performed in the center . Patients were weighed on the same calibrated scale each morning while wearing a hospital gown . Baseline blood specimens were collected on days 4 and 0 to examine within-participant variation in HIV RNA level in the absence of experimental therapies . Follow-up specimens were obtained on days 2 , 5 , 8 , 11 , 14 , 17 , 19 , and 21 . Sample s were stored at 70 C and batch-tested for HIV RNA at the end Rationale Nighttime agitation occurs frequently in patients with dementia and represents the number one burden on caregivers today . Current treatment options are few and limited due to substantial side effects . Objectives The aim of the study was to measure the effect of the cannabinoid dronabinol on nocturnal motor activity . Methods In an open-label pilot study , six consecutive patients in the late stages of dementia and suffering from circadian and behavioral disturbances — five patients with Alzheimer ’s disease and one patient with vascular dementia — were treated with 2.5 mg dronabinol daily for 2 weeks . Motor activity was measured objective ly using actigraphy . Results Compared to baseline , dronabinol led to a reduction in nocturnal motor activity ( P=0.028 ) . These findings were corroborated by improvements in Neuropsychiatric Inventory total score ( P=0.027 ) as well as in subscores for agitation , aberrant motor , and nighttime behaviors ( P<0.05 ) . No side effects were observed . Conclusions The study suggests that dronabinol was able to reduce nocturnal motor activity and agitation in severely demented patients . Thus , it appears that dronabinol may be a safe new treatment option for behavioral and circadian disturbances in dementia
This review finds no evidence that cannabinoids are effective in the improvement of disturbed behaviour in dementia or in the treatment of other symptoms of dementia .
BACKGROUND Following the discovery of an endogenous cannabinoid system and the identification of specific cannabinoid receptors in the central nervous system , much work has been done to investigate the main effects of these compounds .
There is increasing evidence that the cannabinoid system may regulate neurodegenerative processes such as excessive glutamate production , oxidative stress and neuroinflammation .
Neurodegeneration is a feature common to the various types of dementia and this has led to interest in whether cannabinoids may be clinical ly useful in the treatment of people with dementia .
Recent studies have also shown that cannabinoids may have more specific effects in interrupting the pathological process in Alzheimer 's disease .
OBJECTIVES To determine from available research whether cannabinoids are clinical ly effective in the treatment of dementia .