multiple sclerosis

Sativex (tetrahydrocannabinol and cannabidiol) and the European experience in medically refractory spasticity in multiple sclerosis

Virginia Thornley, M.D., Neurologist, Epileptologist
March 12, 2018

Introduction

Sativex has been available in Europe since 2010. It is a combination of tetrahydrocannabinol and cannabidiol at a ratio of 1:1 and has been found to be effective in spasticity resistant to medications in patients with multiple sclerosis. Spasticity is the increased tone seen in the muscles due to abnormalities in the central nervous system such as the white matter lesions seen in multiple sclerosis.

Sativex and medically refractory spasticity in multiple sclerosis

Sativex is a THC:CBD (tetrahydrocannabinol:cannabidiol) preparation taken oromucosally which was approved in European countries for the treatment of medically refractory spasticity in patients with multiple sclerosis. Sativex contains a 1:1 ratio of THC to CBD, where THC interacts with CBD receptors to reduce spasticity while CBD ameliorates the side effects often seen with THC. In one large clinical trial of 1615 patients, 42% showed improvement of spasticity in the first 4 weeks, defined as > or = to 20% reduction in spasticity. The responders were double-blinded and grouped under placebo or THC:CBD, a larger proportion of patients had significant response compared to placebo, > or = to 30% reduction of NRS score for spasticity. 47% had adverse effects including fatigue and dizziness. Reported side effects included psychiatric disturbances, 55 had cognitive (attention problems, cognitive worsening and memory problems) and psychiatric issues (confusion, panic attacks, hallucinations, depression and suicidal ideations). Fatigue, drowsiness, dizziness, gastrointestinal symptoms, mouth discomfort and allergic reactions were other reported side effects. There was no evidence of abuse or addiction in the patients. There were significant side effects deemed unrelated to Sativex including, myocardial infarct, hypertensive crisis (2).

In the original MOVE 2 trial in Italy, in the 322 patients studied, the NRS numerical rating scale decreased by -19.1% from baseline time to 3 months of treatment with Sativex. At visit 3 at 3 months, 24.6% were considered relevant responders to the medication with 30% or more reduction in spasticity. Side effects of >1% included somnolence, dizziness, and fatigue. 41 patients reported side effects 3 were serious side effects of which one was not related (3).

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Sativex and studies in Germany, United Kingdom, Switzerland and Spain

Sativex was first approved in Spain and the United Kingdom in 2010 for use in spasticity related to multiple sclerosis. Data were collected to study continued efficacy and safety profiles.  941 patients (761 from the UK, 178 from Germany and 2 from Switzerland) were studied. Data was collected up until January of 2015.  A patient registry was set up as per guidelines before new medications are approved. Patients from the UK were 22% of the patients registered in the UK using that medication since 2010. Continuation rates were 1 year for 68% of patients. Among those who stopped it, 30% cited lack of effectiveness and 25% described side effects. Some significant side effects include suicidality in 2% and depression in 6%. There was no evidence of abuse, addiction or misuse. The fatigue was within the known safety margins of the drug. The patients used on average 5.9 +/- 4.9 sprays per day

In Spain, 204 patients were evaluated. After 6 months, 143 (70.1%) had benefited from using it for spasticity. After 12 months 64.7% derived beneficial effects. The average dose was 6.6 sprays a day. 41 patients had side effects consisting of psychiatric events, falls, reduced the ability to drive and others. Both study groups in the UK, Germany, Switzerland and in Spain both derived benefits justifying continued used of Sativex. Adverse effects were low, and the mean use of sprays was between 5.9-6.6 which was lower than the clinical trial using 8 sprays (4).

Sativex and timeline when it is found to be ineffective

In one large study in Italy involving 30 multiple sclerosis centers, the discontinuation profile was studied. Patient data from 30 MS centers were collected from a period of January 2014 to January 2015. 39.5% of patients disconnected treatment with Sativex. Spasticity was studied using the EDSS or expanded disability status scale and the patient NRS numerical rating scale 0-10 for spasticity. Information was collected at baseline (T0), 4 weeks (T1), 3 months (T2) and 6 months (T3).

Spasticity was noted in 1615 patients. 1597 (39.5%) discontinued treatment. Of those, 24.8% did not reach 20% effectiveness using the NRS scale. Reasons of discontinuing include lack of effectiveness 23%, side effects 16.3% and lack of compliance 0.8%, lost to follow-up 0.4%, patient choice 0.3% and unknown reasons 2%. Analysis showed that an increase in the NRS scale by 1 point at baseline time corresponded to a lower rate of discontinuation. While an increase in the NRS scale at timeline 2 or at 4 weeks corresponded with worsening spasticity and a higher non-responder rate. They concluded that Sativex is a good option for spasticity and by 4-6 weeks, patients can be reliably identified as responders or non-responders to avoid the cost burden on the healthcare system (1).

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Introduction/Disclaimer

About

Reference

  1. Messina, et al, “Sativex in resistant multiple sclerosis spasticity: discontinuation study in a large population of Italian patients (SA.FE. study), Public Library of Science PLoS One, 2017, 12(8) e0180651
  2. Patti, et al, “Efficacy and safety of cannabinoid oromucosal spray for multiple sclerosis spasticity,” Journal of Neurology, Neurosurgery and Psychiatry, 2016, Sep., 87(9):944-951.
  3. Trojano, et al, “Effectiveness and tolerability of THC/CBD oromucosal spray for multiple sclerosis spasticity in Italy: first data from a large observational study,” European Neurology, 2015, 74:178-185,https://doi.org/10.1159/000441819
  4. Fernandez, et al, “THC:CBD in daily practice: available data from UK, Germany and Spain,”European Neurology, 2016, 75 (supp 1);1-3, https://doi.org/10.1159/000444234
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Epilepsy, Glaucoma, pain, Peripheral neuropathy, Tumor

Medical Marijuana: why the huge disconnect between physicians, laws, policies, and patients?

Virginia Thornley, M.D., Neurologist, Epileptologist

March 11, 2018

Introduction

A patient comes to you asking “Doc, my seizures are getting worse, I really hate the side effects of my medications, I really want to go a different route. Have you heard about medical marijuana?” You start sweating profusely, fidgeting in your seat, thinking of every single reason why not to recommend it and come up with  the standard response, “uh, well, I’m not qualified to recommend it and it’s not FDA approved, plus we don’t really know much about it there could be so many side effects.” And then we have the oldie but goodie response, “there’s not enough large randomized control trials to recommend it.” This scene plays 100,000 times over if not a million times over in physician offices across the country. Patients who are disillusioned with adverse effects of medications are looking towards alternative therapy. As surprising as it sounds, patients with chronic pain do not want to get intoxicated by opioids. In fact, some want to be tapered off of them or refuse them all together. Patients with end-stage cancer at the terminal stage of their lives wish to live a comfortable and humane existence without the need for more chemotherapeutic medications or pain medications that consistently make them feel like a zombie. While other patients with epilepsy may be on 4 different anti-epileptic agents and can no longer function or have a good quality of life because of side effects. There are two sides to every coin.

Why you should be educated on cannabidiol and THC use in medical conditions

If patients do not get their answers from their trusted physicians who they trust with their well-being, their health, the temples of their souls, they will go to great lengths in procuring this knowledge. This is via various sites on the internet some of the dubious nature others are from high quality companies that have been in business even before this seeming treatment fad started. Or, the information may be obtained from their brother-in-law’s friend’s hair stylist who is now pain-free after going through a long course of pain medications including ablative treatments, physical therapy, and acupuncture and has a physician who does recommend it. Like it or not, cannabidiol and tetrahydrocannabinol are alternative treatment options and are gaining more and more traction. To ignore it is to be complacent with the changing direction and landscape of medicine. As patients become more and more disillusioned by the limitation of conventional treatments, attention is directed towards alternative regimens. It is not just for the yoga-practicing patient looking for more natural methods, one sees the sweet 83-year-old gentleman who must be someone’s grandfather with the chronic hip pain of 50 years who have failed opioids and is simply looking for pain relief.

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Is there any evidence that it works?

The endocannabinoid pathway is found naturally in the system. It is responsible for the runner’s sense of wellbeing one gets after a 5-mile run and the pleasant mood you get after a 1-hour work-out with Zumba. There are 2 receptors in the system CB1 receptor which has the highest number of brain cells and the CB2 receptor which is found predominantly in the immune system. There are 2 common cannabinoids cannabidiol and tetrahydrocannabinol which exert various medical effects. Cannabidiol (CBD) has a weak affinity for the CB1 receptor and one needs 100 times the amount to get the same euphoria that one gets from tetrahydrocannabinol, the bane of every ER physician. Unfortunately, the side effects of euphoria of THC have preceded its popularity as a medical product. Little do we know it was once used for hundreds of years as a medication before the psychoactive properties were exploited for recreational purposes. In urologic culture cell lines, it is found that cannabinoids may reduce proliferation of cancer cells and reduce the pro-inflammatory microenvironment that is necessary for metastatic conditions (1). Human studies are still needed to determine a reduction in tumor loads. THC receptors are found in retinal cells and may be found to reduce intraocular pressure in glaucoma (5, 6). Cannabidiol is found to bind to the 5HT1 receptor which reduces anxiety. THC has been well-established in the mouse model to promote the inhibitory control of excitatory pathways in the hippocampus, where seizures commonly arise (8). There is an increase in CB1 receptors after prolonged seizures suggesting a compensatory response.  It has been used in combination and found in several randomized control trials to reduce the frequency of seizures by as much as 36% in medically refractory patients (2). It is well-established that cannabinoids reduce pain refractory to conventional medications (3). It has been found in bench research to be an antioxidant and have anti-inflammatory properties (4, 7). Some studies cite side effects of somnolence, nausea, dysphoria, however, it is not clear what was the quality of cannabinoids or dosages were used. At high doses, while THC can reduce pain it may also result in side effects, which is why it is usually used in combination with CBD which ameliorates the side effects of THC.  In addition, cannabidiol by itself has no euphoria and it takes 100 times the amount to achieve intoxication seen with THC use. Synthetic products will have more side effects than products that are organic meaning only of natural materials.

Given the huge amount of evidence in several different medical conditions (3), the results should overwhelmingly be towards a push in using cannabinoids more frequently. However, because of the cynicism of the public, physicians even of patients, who have been exposed more frequently to the harmful psychoactive side effects, the benefits are far overshadowed. More clinical randomized controlled trials are needed. Most literature cites small numbers of patients enrolled in studies or review multiple medical centers where the conditions are not uniform. In addition, some of the patients that would benefit the most are the least in numbers such as those with rare neurological conditions such as Dravet syndrome or Lennox-Gastuat syndrome.

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In conclusion

As it still stands, many states still do not recognize the medicinal value of cannabidiol or tetrahydrocannabinol. In some states, medical physicians are not allowed to recommend it and put themselves at risk for FBI questioning in even suggesting its use. It is not uncommon for patients to move states or order from other states or countries to procure this liquid gold that is supposed to work wonders. Only time will tell if this is a passing fad and if there are long-standing side effects, however, as of current standing, medical marijuana is here to stay. As far as the literature goes, there are beneficial results but it is a cautionary tale as more studies in large human trials are still needed. As with any new preclinical data, the preclinical status may get ahead of itself and human trials do not replicate the desired results. But from the small clinical trials in seizures, pain, nausea, anxiety, and loss of appetite, the results are promising while more research is needed for anti-tumor effects in humans.

As with any medication, there will be clear-cut side effects just as with any other medication which is why more studies are needed to determine the least amount with the least amount of side effects. In some studies,  amounts upwards of 50mg/kg (2) is used the high amounts likely responsible for causing side effects, which is far higher than that cautioned by medical marijuana dispensaries. It will take patients time to wrap their heads around taking guidance from a fresh-faced 20-year-old millennial at the spa-like dispensary which is currently the norm at most dispensaries, who likely knows much more than even most medical professionals. It seems it will take even longer in Congress to understand the potential benefit of cannabinoids from a medical standpoint especially with the present opioid epidemic. Countries in Europe have far surpassed the United States when it comes to cutting-edge treatments. Perhaps, it will take even longer for the medical community to see the medical potential with their exposure to the sinister side of tetrahydrocannabinol seen in patients in the ER for non-medical reasons, which may be one of the most challenging stumbling blocks.

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Introduction/Disclaimer

References:

  1. Ghandhi, et al, “Systemic review of the potential role of cannabinoids as anti-proliferative agents for urological cancer,” Can. Urol. Assoc. J., 2017, May,-April., 11(3-4):E138-E142.
  2. Devinsky, et al, “Cannabidiol in patients with treatment-resistant epilepsy: an open-label interventional trial,” Lancet Neurology, 2016, Mar., 15(3):270-280.
  3. Petzke, et al, “Efficacy, tolerability, and safety of cannabinoids for chronic neuropathic pain: a systemic review of randomized controlled studies,” Schmerz, 2016, Feb., 30(1):62-88.
  4. Rajan. et al, “Gingival stromal cells as an in vitro model: cannabidiol modulates genes linked with amyotrophic lateral sclerosis,” Journal of Cellular Biochemistry, 2017, Apr., 118(4):819-828.
  5. ElSohly, et al, “Cannabinoids in glaucoma II: the effect of different cannabinoids on intraocular pressure on rabbits,”Current Eye Research, 1984, Jun., 3(6):841-50.
  6. Jarvinen, T., “Cannabinoids in the treatment of glaucoma,” Pharmacology and Therapeutics, 2002, Aug., 95(2):203-20.
  7. Carroll, et al, “9-Tetrahydrocannabinol exerts a direct neuroprotective effect in human cell culture model of Parkinson’s disease,” Neuropathology and Applied Neuropharmacology, 2012, Oct., 38(6):3535-547.
  8. Kaplan, et al, “Cannabidiol attenuates seizures and social deficits in a mouse model in Dravet syndrome,” Proceedings of the National Academy of Science, 2017, Oct.
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Epilepsy

Cannabidiol: mechanisms and efficacy in medically refractory epilepsy

Virginia Thornley, M.D., Neurologist, Epileptologist

March 9, 2018

Introduction

One of the most challenging therapeutic goals are to keep patients with epilepsy seizure free. Once a patient is found to be medically refractory, it is not unusual to find patients on 3-4 medications for seizure control. However, oftentimes, the means to the end is often wrought with its own challenges with patients suffering side effects placing their quality of life secondary to the medical control of their condition. More and more patients and their families are turning towards a more naturalistic approach including diet and cannabidiol use which has fewer side effects as a means to control seizures. The literature is fraught with a paucity of scientific data with small clinical trials, animal models, and anecdotal data. Larger clinical randomized control trials are pursued.

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Mechanisms of Cannabidiol and THC

In the brain, there is the natural endocannabinoid system. Endocannabinoids are released after exercise referred to as the runner’s high which contributes towards our sense of well-being. In the endocannabinoid pathway, cannabidiol has a low affinity to the CB1 receptor and modulates THC tetrahydrocannabinol by blocking CB1 receptor. It is thought to modulate THC by blocking the CB1 receptor acting as an inverse CB1 agonist (2). This may be the mechanism behind combining CBD with THC, CBD modulates the side effects of THC making it less available to exert its effects. Delta9THC is found to work at the level of the CB1 receptors which are rich in the brain and CB2 receptor which is more predominant in the immune system. THC can bind to other targets exerting inflammatory properties. CBD has less binding capabilities to CB1 receptors and is thought to exert its effect by working through other mechanisms such as voltage-gated potassium and sodium channels and the GRP55 in controlling seizures. Cannabinoids are lipid binding or lipophilic making it less available within the system making it challenging to deliver (3).

Cannabidiol clinical trials

In one study, 216 patients were enrolled and followed 3 months after administration of the first dose cannabidiol. Initially, the dose was 2mg/kg which was titrated up to 50mg/kg. 76% were enrolled in the safety profile study and 64% were enrolled in the efficacy profile study. In the first group for safety, 20% had Dravet syndrome and 19% had Lennox-Gastaut syndrome. Side effects were noted in 79% of the patients in the safety group. These include somnolence, diarrhea, seizures (11%), fatigue and reduced appetite. Five disenrolled due to adverse effects, 30% had serious side effects including 1 death of consisting sudden death syndrome. 12% had serious side effects including status epilepticus which may have been related to cannabidiol use. The median reduction of seizures was 36.5%. The study concluded that cannabidiol may be an effective strategy for reducing seizures in medically refractory seizures. The flaw with the study is that the doses at the higher end may have been too high for the patients to tolerate, a lower titrated dose may have been equally effective in controlling seizures and minimizing side effects. Nevertheless, the results were promising as it proves to be beneficial in controlling some of the seizures.

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Introduction/Disclaimer

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References

  1. Devinsky, et al, “Cannabidiol in patients with treatment-resistant epilepsy: an open-label interventional trial,” Lancet Neurology, 2016, Mar., 15(3):270-280.
  2. McPartland, et al, “Are cannabidiol and 9 delta tetrahydrocannabivarin negative modulators of the endocannabinoid system? A systematic review,” British Journal of Pharmacology, 2015, Feb., 172(3):737-53.
  3. Gaston, et al, “Pharmacology of cannabinoids in the treatment of epilepsy,” Epilepsy Behavior, 2017, May, 70(Pt B):313-318.

 

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