Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0030193 (pain)
 261,466 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cannabinoid CB(2) receptors have been implicated in antinociception in animal models of both acute and chronic pain. We evaluated the role both cannabinoid CB(1) and CB(2) receptors in mechanonociception in non-arthritic and arthritic rats. The antinociceptive effect of Delta(9)-tetrahydrocannabinol (Delta(9)THC) was determined in rats following administration of the cannabinoid CB(1) receptor-selective antagonist, SR141716A, the cannabinoid CB(2) receptor-selective antagonist, SR144528, or vehicle. Male Sprague-Dawley rats were rendered arthritic using Freund's complete adjuvant and tested for mechanical hyperalgesia in the paw-pressure test. Arthritic rats had a baseline paw-pressure of 83 +/- 3.6 g versus a paw-pressure of 177 +/- 6.42 g in non-arthritic rats. SR144528 or SR141716A (various doses mg/kg; i.p.) or 1:1:18 (ethanol:emulphor:saline) vehicle were injected 1 h prior to Delta(9)THC (4 mg/kg; i.p) or 1:1:18 vehicle and antinociception determined 30min post Delta(9)THC. AD(50)'s for both antagonists were calculated with 95% confidence limits. In addition, midbrain and spinal cord were removed for determination of cannabinoid CB(1) and CB(2) receptor protein density in the rats. SR144528 significantly attenuated the antinociceptive effect of Delta(9)THC in the arthritic rats [AD(50) = 3.3 (2.7-4) mg/kg], but not in the non-arthritic rats at a dose of 10/mg/kg. SR141716A significantly attenuated Delta(9)THC-induced antinociception in both the non-arthritic [AD(50) = 1.4 (0.8-2) mg/kg] and arthritic rat [AD(50) = 2.6 (1.8-3.1) mg/kg]. SR141716A or SR144528 alone did not result in a hyperalgesic effect as compared to vehicle. Our results indicate that the cannabinoid CB(2) receptor plays a critical role in cannabinoid-mediated antinociception, particularly in models of chronic inflammatory pain.
 ...
PMID:The antinociceptive effect of Delta9-tetrahydrocannabinol in the arthritic rat involves the CB(2) cannabinoid receptor. 1758 60

The objective of this study was to review demographic characteristics and drugs detected in carbon monoxide (CO)-related deaths from cases received by the Office of the Cuyahoga County Coroner in Cleveland, Ohio, from 2000-2003. Postmortem reports were reviewed, and decedents for which CO was listed as the cause of death were included. The data were compiled into 3 groups according to the official coroner's verdict as to the manner of death: accident, suicide, and homicide. Included in this study were 122 cases: 84 (69%) accidental, 31 (25%) suicide, and 7 (6%) homicide. Accident decedents were typically white males, aged 40-59 years, residing in Cleveland. Suicide decedents were also middle-aged, white males but residing in the suburbs. Homicide decedents under the age of 6 were characteristically black (N=2), while decedents over the age of 39 were predominately white (N=3). Carboxyhemoglobin (COHb) levels in suicide cases were higher than concentrations measured in accidental deaths. The highest percentage of suicide decedents (36%) had a COHb level>70% saturation, accident decedents (36%) between 50% and 69% saturation, and homicide decedents (71%) below 50% saturation. Ethanol (N=34) was detected in 28% of deaths, and therapeutic and/or abused drugs (N=50) were detected in 41% of deaths. Illicit drugs were detected in 11% of cases (cocaine/metabolites; THC/metabolites), other drug positives were therapeutic medications. The most common drugs detected were antidepressants and antihistamines in suicides and pain medications and antihistamines in accidents.
 ...
PMID:The prevalence of drugs in carbon monoxide-related deaths: a retrospective study, 2000-2003. 1772 Nov 77

Cannabinoids are known to have analgesic properties. We evaluated the effect of oro-mucosal sativex, (THC: CBD), an endocannabinoid system modulator, on pain and allodynia, in 125 patients with neuropathic pain of peripheral origin in a five-week, randomised, double-blind, placebo-controlled, parallel design trial. Patients remained on their existing stable analgesia. A self-titrating regimen was used to optimise drug administration. Sixty-three patients were randomised to receive sativex and 62 placebo. The mean reduction in pain intensity scores (primary outcome measure) was greater in patients receiving sativex than placebo (mean adjusted scores -1.48 points vs. -0.52 points on a 0-10 Numerical Rating Scale (p=0.004; 95% CI: -1.59, -0.32). Improvements in Neuropathic Pain Scale composite score (p=0.007), sleep NRS (p=0.001), dynamic allodynia (p=0.042), punctate allodynia (p=0.021), Pain Disability Index (p=0.003) and Patient's Global Impression of Change (p<0.001) were similarly greater on sativex vs. placebo. Sedative and gastrointestinal side effects were reported more commonly by patients on active medication. Of all participants, 18% on sativex and 3% on placebo withdrew during the study. An open-label extension study showed that the initial pain relief was maintained without dose escalation or toxicity for 52 weeks.
Pain 2007 Dec 15
PMID:Sativex successfully treats neuropathic pain characterised by allodynia: a randomised, double-blind, placebo-controlled clinical trial. 1799 24

We have previously demonstrated synergy between morphine and Delta(9)-tetrahydrocannabinol (Delta(9)-THC) in the expression of antinociception in acute pain models and in arthritic models of chronic pain. Our data has been extended to include acute pain in both diabetic mice and rats. In diabetic mice, Delta(9)-THC p.o. was more active in the tail-flick test in the diabetic mouse than in the non-diabetic mouse. Morphine (s.c.) was less potent in diabetic than in non-diabetic mice [6.1 (5.1-7.2) versus 3.2 (2.4-4.1) mg/kg, respectively], an effect previously extensively documented in pre-clinical and clinical testing. In addition, the combination of Delta(9)-THC with morphine produced a greater-than-additive relief of acute pain in mice. In the rat, the induction of the diabetic state decreased the antinociceptive effect of morphine, an effect temporally related to a decreased release of specific endogenous opioids. Conversely, Delta(9)-THC retained the ability to release endogenous opioids in diabetic rats and maintained significant antinociception. Extrapolation of such studies to the clinical setting may indicate the potential for use of Delta(9)-THC-like drugs in the treatment of diabetic neuropathic pain, alone or in combination with very low doses of opioids.
 ...
PMID:Decreased basal endogenous opioid levels in diabetic rodents: effects on morphine and delta-9-tetrahydrocannabinoid-induced antinociception. 1831 63

During the 1990s, transmembranal proteins in the central nervous system (CNS) that recognize the principal compound of marijuana, the delta-9-tetrahydrocannabinol (Delta9-THC) were described. The receptors were classified as central or peripheral, CB1 and CB2, respectively. To this date, it has been documented the presence in the CNS of specific lipids that bind naturally to the CB1/CB2 receptors. The family of endogenous cannabinoids or endocannabinoids comprises oleamide, arachidonoylethanolamine, 2-arachidonylglycerol, virodhamine, noladin ether and N-arachidonyldopamine. Pharmacological experiments have shown that those compounds induce cannabimimetic effects. Endocannabinoids are fatty acid derivates that have a variety of biological actions, most notably via activation of the cannabinoid receptors. The endocannabinoids have an active role modulating diverse neurobiological functions, such as learning and memory, feeding, pain perception and sleep generation. Experimental evidence shows that the administration of Delta9-THC promotes sleep. The activation of the CB1 receptor leads to an induction of sleep, this effect is blocked via the selective antagonist. Since the system of the endogenous cannabinoids is present in several species, including humans, this leads to the speculation of the neurobiological role of the endocannabinoid system on diverse functions such as sleep modulation. This review discusses the evidence of the system of the endocannabinoids as well as their physiological role in diverse behaviours, including the modulation of sleep.
 ...
PMID:The role of the CB1 receptor in the regulation of sleep. 1851 75

Advances in cannabis research have paralleled developments in opioid pharmacology whereby a psychoactive plant extract has elucidated novel endogenous signalling systems with therapeutic significance. Cannabinoids (CBs) are chemical compounds derived from cannabis. The major psychotropic CB delta-9-tetrahydrocannabinol (Delta(9)-THC) was isolated in 1964 and the first CB receptor (CB(1)R) was cloned in 1990. CB signalling occurs via G-protein-coupled receptors distributed throughout the body. Endocannabinoids are derivatives of arachidonic acid that function in diverse physiological systems. Neuronal CB(1)Rs modulate synaptic transmission and mediate psychoactivity. Immune-cell CB(2) receptors (CB(2)R) may down-regulate neuroinflammation and influence cyclooxygenase-dependent pathways. Animal models demonstrate that CBRs play a fundamental role in peripheral, spinal, and supraspinal nociception and that CBs are effective analgesics. Clinical trials of CBs in multiple sclerosis have suggested a benefit in neuropathic pain. However, human studies of CB-mediated analgesia have been limited by study size, heterogeneous patient populations, and subjective outcome measures. Furthermore, CBs have variable pharmacokinetics and can manifest psychotropism. They are currently licensed as antiemetics in chemotherapy and can be prescribed on a named-patient basis for neuropathic pain. Future selective peripheral CB(1)R and CB(2)R agonists will minimize central psychoactivity and may synergize opioid anti-nociception. This review discusses the basic science and clinical aspects of CB pharmacology with a focus on pain medicine.
 ...
PMID:Therapeutic potential of cannabis in pain medicine. 1851 70

This article reviews recent research on cannabinoid analgesia via the endocannabinoid system and non-receptor mechanisms, as well as randomized clinical trials employing cannabinoids in pain treatment. Tetrahydrocannabinol (THC, Marinol((R))) and nabilone (Cesamet((R))) 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((R)), a cannabis derived oromucosal spray containing equal proportions of THC (partial CB(1) receptor agonist ) and cannabidiol (CBD, a non-euphoriant, anti-inflammatory analgesic with CB(1) 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 randomized 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.
 ...
PMID:Cannabinoids in the management of difficult to treat pain. 1872 14

Cannabinoids have been used for pain relief for centuries and recent studies have investigated their analgesic and anti-inflammatory mechanisms, as well as clinical efficacy, in treating chronic pain. We report an open-label study addressed to evaluate the effect and adverse events of orally administered Delta-9-tetrahydrocannabinol (Delta-9-THC) in 13 patients with chronic nonmalignant pain (CNMP) unresponsive to conventional pharmacotherapy. The effect of the treatment was assessed on an eight-item HRQoL questionnaire. Five out of 13 patients reported adequate response to the treatment while eight patients reported inadequate or no response. Seven patients did not experience any adverse events (AEs), six patients reported AEs, two of which discontinued the treatment. We conclude that oral THC may be a valuable therapeutic option for selected patients with CNMP that are unresponsive to previous treatments, though further research is warranted to characterize those patients.
J Pain Palliat Care Pharmacother 2008
PMID:Open-label, add-on study of tetrahydrocannabinol for chronic nonmalignant pain. 1904 51

Considerable preclinical research has demonstrated the efficacy of Delta(9)-tetrahydrocannabinol (Delta(9)-THC), the primary psychoactive constituent of Cannabis sativa, in a wide variety of animal models of pain, but few studies have examined other phytocannabinoids. Indeed, other plant-derived cannabinoids, including cannabidiol (CBD), cannabinol (CBN), and cannabichromene (CBC) elicit antinociceptive effects in some assays. In contrast, tetrahydrocannabivarin (THCV), another component of cannabis, antagonizes the pharmacological effects of Delta(9)-THC. These results suggest that various constituents of this plant may interact in a complex manner to modulate pain. The primary purpose of the present study was to assess the antinociceptive effects of these other prevalent phytocannabinoids in the acetic acid stretching test, a rodent visceral pain model. Of the cannabinoid compounds tested, Delta(9)-THC and CBN bound to the CB(1) receptor and produced antinociceptive effects. The CB(1) receptor antagonist, rimonabant, but not the CB(2) receptor antagonist, SR144528, blocked the antinociceptive effects of both compounds. Although THCV bound to the CB(1) receptor with similar affinity as Delta(9)-THC, it had no effects when administered alone, but antagonized the antinociceptive effects of Delta(9)-THC when both drugs were given in combination. Importantly, the antinociceptive effects of Delta(9)-THC and CBN occurred at lower doses than those necessary to produce locomotor suppression, suggesting motor dysfunction did not account for the decreases in acetic acid-induced abdominal stretching. These data raise the intriguing possibility that other constituents of cannabis can be used to modify the pharmacological effects of Delta(9)-THC by either eliciting antinociceptive effects (i.e., CBN) or antagonizing (i.e., THCV) the actions of Delta(9)-THC.
 ...
PMID:Evaluation of prevalent phytocannabinoids in the acetic acid model of visceral nociception. 1967 11

Neuropathic pain is a debilitating form of chronic pain resulting from nerve injury, disease states, or toxic insults. Neuropathic pain is often refractory to conventional pharmacotherapies, necessitating validation of novel analgesics. Cannabinoids, drugs that share the same target as Delta(9)-tetrahydrocannabinol (Delta(9)-THC), the psychoactive ingredient in cannabis, have the potential to address this unmet need. Here, we review studies evaluating cannabinoids for neuropathic pain management in the clinical and preclinical literature. Neuropathic pain associated with nerve injury, diabetes, chemotherapeutic treatment, human immunodeficiency virus, multiple sclerosis, and herpes zoster infection is considered. In animals, cannabinoids attenuate neuropathic nociception produced by traumatic nerve injury, disease, and toxic insults. Effects of mixed cannabinoid CB(1)/CB(2) agonists, CB(2) selective agonists, and modulators of the endocannabinoid system (i.e., inhibitors of transport or degradation) are compared. Effects of genetic disruption of cannabinoid receptors or enzymes controlling endocannabinoid degradation on neuropathic nociception are described. Specific forms of allodynia and hyperalgesia modulated by cannabinoids are also considered. In humans, effects of smoked marijuana, synthetic Delta(9)-THC analogs (e.g., Marinol, Cesamet) and medicinal cannabis preparations containing both Delta(9)-THC and cannabidiol (e.g., Sativex, Cannador) in neuropathic pain states are reviewed. Clinical studies largely affirm that neuropathic pain patients derive benefits from cannabinoid treatment. Subjective (i.e., rating scales) and objective (i.e., stimulus-evoked) measures of pain and quality of life are considered. Finally, limitations of cannabinoid pharmacotherapies are discussed together with directions for future research.
 ...
PMID:Cannabinoids as pharmacotherapies for neuropathic pain: from the bench to the bedside. 1978 75


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>