Category Archives: Chronic Inflammatory and Neuropathic Pain

Ventilatory-depressant effects of opioids alone and in combination with cannabinoids in rhesus monkeys.

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“Pain is a serious health problem that is commonly treated with opioids, although the doses of opioids needed to treat pain are often similar to those that decrease respiration. Combining opioids with drugs that relieve pain through non-opioid mechanisms can decrease the doses of opioids needed for analgesia, resulting in an improved therapeutic window, but only if the doses of opioids that decrease respiration are not similarly decreased. Using small doses of opioids to treat pain has the potential to reduce the number of overdoses and deaths.

This study investigated whether the cannabinoid receptor agonists Δ9-tetrahydrocannabinol (Δ9-THC) and CP 55,940 modify the ventilatory-depressant effects of morphine and fentanyl in three monkeys.

In summary, cannabinoid receptor agonists, which increase the potency of opioids to produce antinociception, did not increase their potency to depress ventilation. Thus, the therapeutic window is greater for opioids when they are combined with cannabinoid receptor agonists, indicating a possible advantage for these drug mixtures in treating pain.”

https://www.ncbi.nlm.nih.gov/pubmed/29807027

https://www.sciencedirect.com/science/article/pii/S0014299918303108

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

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“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.

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.”

 https://www.ncbi.nlm.nih.gov/pubmed/29797104
https://thejournalofheadacheandpain.springeropen.com/articles/10.1186/s10194-018-0862-2

Self-initiated use of topical cannabidiol oil for epidermolysis bullosa.

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“Epidermolysis bullosa is a rare blistering skin disorder that is challenging to manage because skin fragility and repeated wound healing cause itching, pain, limited mobility, and recurrent infections.

Cannabidiol, an active cannabinoid found in cannabis, is postulated to have antiinflammatory and analgesic effects.

We report 3 cases of self-initiated topical cannabidiol use in patients with epidermolysis bullosa in an observational study.

One patient was weaned completely off oral opioid analgesics. All 3 reported faster wound healing, less blistering, and amelioration of pain with cannabidiol use.

Although these results demonstrate promise, further randomized, double-blind clinical trials are necessary to provide scientific evidence of our observed benefits of cannabidiol for the treatment of epidermolysis bullosa.”

https://www.ncbi.nlm.nih.gov/pubmed/29786144

https://onlinelibrary.wiley.com/doi/abs/10.1111/pde.13545

Overcoming the Bell-Shaped Dose-Response of Cannabidiol by Using Cannabis Extract Enriched in Cannabidiol

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“Cannabidiol (CBD), a major constituent of Cannabis, has been shown to be a powerful anti-inflammatory and anti-anxiety drug, without exerting a psychotropic effect. However, when given either intraperitoneally or orally as a purified product, a bell-shaped dose-response was observed, which limits its clinical use.
In the present study, we have studied in mice the anti-inflammatory and anti-nociceptive activities of standardized plant extracts derived from the Cannabis sativa L., clone 202, which is highly enriched in CBD and hardly contains any psychoactive ingredients.
In stark contrast to purified CBD, the clone 202 extract, when given either intraperitoneally or orally, provided a clear correlation between the anti-inflammatory and anti-nociceptive responses and the dose, with increasing responses upon increasing doses, which makes this plant medicine ideal for clinical uses.
The clone 202 extract reduced zymosan-induced paw swelling and pain in mice, and prevented TNFα production in vivo. It is likely that other components in the extract synergize with CBD to achieve the desired anti-inflammatory action that may contribute to overcoming the bell-shaped dose-response of purified CBD.
We therefore propose that Cannabis clone 202 (Avidekel) extract is superior over CBD for the treatment of inflammatory conditions.”  https://www.scirp.org/journal/PaperInformation.aspx?paperID=53912
“In conclusion, we recommend standardized plant extract of the Cannabis clone 202 for treatment of various inflammatory conditions.” https://file.scirp.org/Html/5-2500582_53912.htm

Cannabinoid 1 receptors are expressed in nociceptive primary sensory neurons.

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“Expression of cannabinoid 1 (CB1) and vanilloid 1 (VR1) receptor proteins was studied in adult, cultured rat dorsal root ganglion neurons. Immunostaining of CB1 receptors alone produced labelling in 57+/-2% of the cultured dorsal root ganglion neurons (n=3 cultures). The area of the labelled cells was between 200 and 800 microm(2) with an average of 527+/-68 microm(2). VR1 immunolabelling revealed immunopositivity in 42+/-6% of the total population of dorsal root ganglion neurons. Cells showing VR1-like immunopositivity had an area between 200 and 600 microm(2). The mean area of the VR1-like immunopositive neurons was 376+/-61 microm(2). Double immunostaining with antisera raised against the CB1 and VR1 receptor proteins, showed a high degree of co-expression between CB1 and VR1 receptors. An average of 82+/-3% of the CB1-like immunopositive cells also showed VR1-like immunoreactivity (n=3 cultures) while 98+/-2% of the VR1-like immunolabelled neurons showed CB1 receptor-like immunostaining (n=3 cultures). Our data suggests that nociceptive primary sensory neurons co-express CB1 and VR1 receptors to a very high degree. We propose that this may provide an anatomical basis for a powerful combination of VR1 mediated excitation and CB1-mediated inhibition of nociceptive responses at central and peripheral terminals of nociceptive primary afferents.”

https://www.ncbi.nlm.nih.gov/pubmed/11036202

https://www.sciencedirect.com/science/article/abs/pii/S0306452200003894

Possible mechanisms of cannabinoid-induced antinociception in the spinal cord.

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European Journal of Pharmacology

“Anandamide is an endogenous ligand at both the inhibitory cannabinoid CB(1) receptor and the excitatory vanilloid receptor 1 (VR1). The CB(1) receptor and vanilloid VR1 receptor are expressed in about 50% and 40% of dorsal root ganglion neurons, respectively. While all vanilloid VR1 receptor-expressing cells belong to the calcitonin gene-related peptide-containing and isolectin B4-binding sub-populations of nociceptive primary sensory neurons, about 80% of the cannabinoid CB(1) receptor-expressing cells belong to those sub-populations. Furthermore, all vanilloid VR1 receptor-expressing cells co-express the cannabinoid CB(1) receptor.

In agreement with these findings, neonatal capsaicin treatment that induces degeneration of capsaicin-sensitive, vanilloid VR1 receptor-expressing, thin, unmyelinated, nociceptive primary afferent fibres significantly reduced the cannabinoid CB(1) receptor immunostaining in the superficial spinal dorsal horn.

Synthetic cannabinoid CB(1) receptor agonists, which do not have affinity at the vanilloid VR1 receptor, and low concentrations of anandamide both reduce the frequency of miniature excitatory postsynaptic currents and electrical stimulation-evoked or capsaicin-induced excitatory postsynaptic currents in substantia gelatinosa cells in the spinal cord without any effect on their amplitude. These effects are blocked by selective cannabinoid CB(1) receptor antagonists. Furthermore, the paired-pulse ratio is increased while the postsynaptic response of substantia gelatinosa neurons induced by alpha-amino-3-hydroxy-5-methylisoxasole-propionic acid (AMPA) in the presence of tetrodotoxin is unchanged following cannabinoid CB(1) receptor activation.

These results strongly suggest that the cannabinoid CB(1) receptor is expressed presynaptically and that the activation of these receptors by synthetic cannabinoid CB(1) receptor agonists or low concentration of anandamide results in inhibition of transmitter release from nociceptive primary sensory neurons. High concentrations of anandamide, on the other hand, increase the frequency of miniature excitatory postsynaptic currents recorded from substantia gelatinosa neurons. This increase is blocked by ruthenium red, suggesting that this effect is mediated through the vanilloid VR1 receptor.

Thus, anandamide at high concentrations can activate the VR1 and produce an opposite, excitatory effect to its inhibitory action produced at low concentrations through cannabinoid CB(1) receptor activation. This “dual”, concentration-dependent effect of anandamide could be an important presynaptic modulatory mechanism in the spinal nociceptive system.”

https://www.ncbi.nlm.nih.gov/pubmed/11698030

https://www.sciencedirect.com/science/article/pii/S0014299901013097?via%3Dihub

The nonpsychotropic cannabinoid cannabidiol modulates and directly activates alpha-1 and alpha-1-Beta glycine receptor function.

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“Loss of inhibitory synaptic transmission within the dorsal horn of the spinal cord plays a key role in the development of chronic pain following inflammation or nerve injury. Inhibitory postsynaptic transmission in the adult spinal cord involves mainly glycine.

Cannabidiol is a nonpsychotropic plant constituent of Cannabis sativa.

As we hypothesized that non-CB receptor mechanisms of cannabidiol might contribute to its anti-inflammatory and neuroprotective effects, we investigated the interaction of cannabidiol with strychnine-sensitive alpha(1 )and alpha(1)beta glycine receptors by using the whole-cell patch clamp technique.

Cannabidiol showed a positive allosteric modulating effect in a low micromolar concentration range (EC(50) values: alpha(1) = 12.3 +/- 3.8 micromol/l and alpha(1)beta = 18.1 +/- 6.2 micromol/l). Direct activation of glycine receptors was observed at higher concentrations above 100 micromol/l (EC(50) values: alpha(1) = 132.4 +/- 12.3 micromol/l and alpha(1)beta = 144.3 +/- 22.7 micromol/l).

These in vitro results suggest that strychnine-sensitive glycine receptors may be a target for cannabidiol mediating some of its anti-inflammatory and neuroprotective properties.”

https://www.ncbi.nlm.nih.gov/pubmed/19204413

https://www.karger.com/Article/Abstract/201556

Effects of cannabinoid type 2 receptor agonist AM1241 on morphine-induced antinociception, acute and chronic tolerance, and dependence in mice.

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“Morphine is a potent opioid analgesic used to alleviate moderate or severe pain but the development of drug tolerance and dependence limits its use in pain management.

Previous studies showed that cannabinoid type 2 (CB2) receptor ligands may modulate opioid effects. However, there is no report of the effect of CB2 receptor agonist on acute morphine tolerance and physical dependence. We therefore investigated the effect of a CB2 receptor agonist (AM1241) on morphine-induced morphine tolerance and physical dependence in mice.

Our findings suggest that coadministration of the CB2 receptor agonist and morphine could increase morphine antinociception and reduce morphine tolerance and physical dependence in mice.

PERSPECTIVE:

Combination of a CB2 agonist and morphine may provide a new strategy for better treatment of acute and chronic pain, and prevention of opioid tolerance and dependence. This may also provide a clue for the treatment of opioid tolerance and dependence in clinic.”

https://www.ncbi.nlm.nih.gov/pubmed/29729431

https://www.sciencedirect.com/science/article/pii/S1526590018301597

“Antinociceptive Synergy between 9 -Tetrahydrocannabinol and Opioids after Oral Administration” http://jpet.aspetjournals.org/content/jpet/304/3/1010.full.pdf

Cannabinoid-Opioid Interaction in Chronic Pain

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“Cannabis inhalation with a vaporizer may enhance the analgesia of opioids.

In addition, previous research suggest that Cannabis may be useful in attenuating the development of opioid tolerance and dependence.

This is the first human study to show that inhaled cannabis safely potentiates the analgesia of opioids.

HUMAN STUDY SHOWS INHALED CANNABIS POTENTIATES ANALGESIA OF OPIOIDS.”

https://www.naturalmedicinejournal.com/journal/2012-06/cannabinoid-opioid-interaction-chronic-pain

Antinociceptive Synergy between 9 -Tetrahydrocannabinol and Opioids after Oral Administration

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“Cannabinoids and opioids have been shown to possess several similar pharmacological effects, including analgesia

The analgesic effects of opioids, such as morphine and codeine, in mice are enhanced by oral administration of the cannabinoid 9 -tetrahydrocannabinol (9 -THC).

These findings suggest that the use of a low-dose combination of analgesics is a valid and effective approach for the treatment of pain and necessitates further study.

In summary, we have observed that 9 -THC enhances the antinociceptive effects of morphine and codeine in a synergistic fashion. This is the first report of a true synergistic interaction between oral 9 -THC and morphine or codeine, since previous studies have only examined one-dose combinations.

Much more work needs to be done to elucidate the mechanisms by which cannabinoids and opioids interact to produce analgesia. However, the implication that a combination of drugs may be more effective than either drug alone, and at the same time possibly reduce the occurrence of side effects, should provoke further study on analgesic drug interactions.”

http://jpet.aspetjournals.org/content/jpet/304/3/1010.full.pdf

http://healthdocbox.com/Substance_Abuse/71109245-Antinociceptive-synergy-between-9-tetrahydrocannabinol-and-opioids-after-oral-administration.html