Jul 04, 2015
Medical Marijuana &
Epilepsy
Derek J Chong, MD, MScAssistant Professor of Neurology
NYU Comprehensive Epilepsy Center
TerminologyCannabis: is the latin name (derived from the Greek Kánnabis for ‘hemp’). It is the scientific term as of 1700’s. Used by botanists and pharmaceutical companies since.
Marijuana: generally refers to the leaves and female flowers (buds) of the cannabis plant. Name derived in USA, from Mexican immigrants who used the term “Mariguana”. Primarily used in negative advertisements in 1930’s to sound ‘foreign’ and ‘dangerous’, also termed ‘locoweed’.
Hashish: derived from “grass” (Arabic), from glands off the Cannabis stalks - a resin
Hemp: is the Cannabis plant, but refers to one grown for purely industrial purposes and has minimal quantities of psychoactive substances (the bare stalks used primarily - rope)
Cannabinoids: substances that act on the cannabinoid receptor on our cells
US slang: “pot” from potiguaya, “weed,” “grass,” “herb,” “smoke”, “ganja” and “dope”
Mexico: “mota”, “pasto” and “gallo”
Argentina: “chala”, Venezuela: “hierba”
Ecuador “tobareto” and “grifa”
Spain: “Maria”, France: “Marie Jeanne”
Endogenous Cannabinoids aka Endocannabinoids (eCBs)
• We make them in our bodies ourselves
• Discovered much later than plant sources
• Lipid (fat)-based, released by the postsynaptic membranes in response to neuronal activity
• Arachidonic acid derivatives produced by neurons and glia, the main 2 are:• 2-Arachidonoylglycerol (2-AG)• N-arachidonoylethanolamide/Anandamide (AEA)
Wilson and Nicoll 2002, Science
Endocannabinoid System: CB1
DiMarzo, 2004
ExcitatoryGlutamatergic Synapse
InhibitoryGABA-ergic Neuron
Synaptic activity
CB1-Recepetor Gene ExpressionMouse Brain
: Activity-dependent activation ofVGCC (increase [Ca2+]i) or mGluR1
Allen Brain Atlases
Exogenous Cannabinoids
CBD = CannabidiolNot psychoactiveVery slight CB1/CB2 indirect antagonistOpposes some CNS effects of THCAntagonist at GPR55 receptor? CBD receptor
THC =Δ9 Tetrahydrocannabinol
Psychoactive/euphoria
CB1 receptor agonist(activator)
Cannabis Species
Cannabis sativa – oldest known species used by
humans (China)
Cannabis indica: reference in Ancient Vedas text in India, ~ 1700 bce
Sativa vs. IndicaBoth species: • 80 terpeno-phenol compounds, “cannabinoids”
• THC and CBD are the 2 main compounds
• >420 compounds: e.g. Eugenol: acts at GABAAreceptors
•Sativa more psychic and stimulatory, sometimes anxiety producing, due to higher THC:CBD ratio •Indica strains have more sedative properties, ‘mellow high’, heavy feeling•Many hybrids with various mixtures of THC:CBD and the other cannabinoids give various effects
Hemp
• Technically Cannabis Sativa• But looks very different, tall and
thin; minimal THC (<0.3%), but also not that much total CBD
Hemp/Cannabis in History
• Cannabis sativa – ? ~8,000 bce in China - rope
• Cultivated, used for garments, bowstrings, paper and medicine in China
• 2700 bce – cannabis for menstruation, gout, rheumatism, malaria, constipation, and absentmindedness (Abel, 1980)
• 1st Century AD in China > 100 ailments
• Medicinal use in ancient Egypt, India, Africa, Greece, Rome and Arab world
Cannabis in the 1800’s
• US Dispensary (1854): neuralgia, depression, hemorrhage, pain and muscle spasm
• Ohio Medical Society Committee on Cannabis Indica (1860): efficacy for neuralgic pain, dysmenorrhea, hysteria, delirium tremens, mania, palsy, whooping cough, infantile convulsions, asthma, nervous rheumatism, chronic bronchitis, spasms, tetanus, epilepsy and appetite stimulation.
Cannabinoids: Animal Models
Compound Species
Number of discrete
conditions/models/designs
DoseAnti-
convulsantNo
effectPromotesSeizures
THC 6 310.25-200
mg/kg61% 29% 10%*
CBD 2 211-400 mg/kg
81% 19% 0%
Other plant cannabinoids
2 7 N/A 100% 0% 0%
CB1 receptor agonists
2 55 N/A 73% 18%2%
(7% mixed effect)
Whalley, 2014 American Herbal Pharmacopoeia
Animal models:Cannabidiol (CBD)
has anti-seizure effects
Most notably, in these studies and others, CBD acts independently of
CB1 receptors in the CNS (unlike endocannabinoids and THC)
Hill et al 2013, Brit J of Pharm
Human Data: Anecdotal
• Davis & Ramsay (1949) – THC for 5 institutionalized children who failed PB & PHT -1 seizure free, 1 almost seizure free; 3 no change
• Consroe et al (1975) - young man with epilepsy on PB & PHT. Marijuana led to seizure freedom added to AEDs, but not alone
• Case reports of marijuana reducing seizure activity, (Mortati et al, 2007) provoking seizures,(Tilleli, 2006), or withdrawal causing a seizure (Hedge et al, 2012)
Survey: Marijuana for Epilepsy
• Tertiary care center: 136 adult patients• 48% lifetime use
• 21% active users, 15% in last month
(Gross et al, 2004)
Survey: 19 Pediatric Epilepsy Patients on CBD>THC
• 19 children (2-16 years) used a CBD-enriched medical marijuana – group on Facebook
• CBD Dose <0.5 mg/kg/day to 28.6 mg/kg/d
• THC amount reported as 0 to 0.8 mg/kg/d
• Diagnoses: Dravet syndrome (13), Doose syndrome (4), Lennox Gastaut syndrome (1), and idiopathic epilepsy (1).
(Porter & Jacobson, Epilepsy & Behavior, 2013)
Survey: 19 Pediatric Epilepsy Patients on CBD-enriched Cannabis
• 16 (84%) reduction in seizure frequency
• 2 were seizure free
• 8 (42%) >80% reduction in seizures
• 6 had a 25-60% reduction in seizures.
• Extra Benefits: improved alertness, mood, and sleep.
• Side effects: drowsiness and fatigue.
(Porter & Jacobson, Epilepsy & Behavior, 2013)
From GW Pharmaceuticals website
CBD Enriched Marijuana
From GW Pharmaceuticals website
CBD Enriched Marijuana
Surveys biased
• People who do worse will not stay on it, and less likely to report in the survey – skews results to only positive outcomes
• People may actually be doing worse, but have no idea• They actually ‘feel great’?
• Just as investigators who want their study to succeed may be biased, parents scoring of seizure frequency and severity may slightly be altered
Four Clinical CBD Trials in Epilepsy
STUDY INCLUSION CRITERIANotes
PT # DOSETIME
EFFICACY SAFETY
Mechoulam (1978)
TLE/TREGroups not matched; ? AEDs, no stats
N=95 CBD5 PLA
200/d x 3 mos 4 Rx’d: 2 Sz free, 1 better, 1 unchanged5 Placebo: unchanged
No adverse events
Cunha (1980)
TLE/TRE >= 1 TCSz/wkDB?
N=157 CBD8 PLA
200-300 mg/d3-18 wks
4 CBD seizure free; 1 control seizure free
Seizure-free:1 placebo4 CBD
Ames (1985)
Residential/MR/TRE-baseline data
N=12? CBD v PLA
200 mg/d x 4wks
No group differences Mild drowsiness
Trembly (1990)
TRE adultsConflict of 90 paper and 92 chapter
N=12 ?CBD v PLA
PLAC x 6 mos, CBD 300/dy x 6 mos
No group diff on seizures or cognitive-behavior tasks
No data
Epidiolex (98% CBD) Studies
• Open-label study of children and young adults with TRE – Dravet, LGS, Focal epilepsy, CDKL4, etc
• 6 sites each to enroll 25 children/site (NYU, UCSF, Lurie Children’s, MGH, CHOP, Great Ormond St)
• NYU enrolled 25, added another 35
• Orphan drug indication approved by FDA for Dravet and LGS – plans for RCT
Preliminary Results
Total of 151 patients enrolled, from 3 sitesData on 58 patients, completed 12 weeks• Average age = 11• Average AEDs = 3• Dravet = 12• Drop seizures = 12
• 10 patients completed 20 weeks• 40 patients completed 16 weeks
58 patients through 12 weeks40 patients through 16 weeks
Dravet patients = 12
Drop seizures = 12LGS 4
Epidiolex: Safety
Retention: 95% of patient remain in study
Common adverse events (occurring in 10% or more patients and resulting from all causes):
• Somnolence - 19% of patients
• Fatigue - 11% of patients
Epidiolex: Adverse Events
• 2 withdrawals from treatment: adverse events
• 4 withdrawals from treatment: lack of clinical effect
• Serious adverse events: in 26 patients• 2 deaths: one from SUDEP, one from respiratory
failure due to aspiration
Open-label studies
• Potential Bias
• Both the patient/caregiver/seizure counter, and the investigator are invested in the product working
• Subconscious bias
• Highlights the need for placebo controlled studies
Phase 3 RCTs
Charlotte’s Web vs CBD
Low THC strains
CBD to THC ratio
20 to 1
RoC: Over 450 patients
Colorado, California
Florida
High-CBD Oil Legalities
• Alabama• Kentucky• Wisconsin• Mississippi• Tennessee• Georgia• South Carolina• Iowa• Florida• North Carolina• Missouri• New YorkPrimarily passed with restrictions limited to use in studies
http://www.mpp.org/states/
Regulate Marijuana like alcohol
Dependence
• Cannabis = risk of addiction• rate estimated at 10% of users (Wagner&Anthony
2002, Winstock 2010)
• CB1-activity = addiction
• CB1-blockers = reduce dependence?
CBD: preliminary evidence shows ANTI-addiction properties
Wolff V et al. Cannabis use, ischemic stroke, and multifocal intracranial vasoconstriction: a prospective study in 48 consecutive young patients. Stroke. 2011 Jun;42(6):1778-80.
Multifocal intracranial stenosis associated with cannabis use: 21% (10/48)
Renard D, Taieb G, Gras-Combe G, Labauge P.J Stroke Cerebrovasc Dis. 2012 Jan;21(1):82-3
Psychiatric side-effects
Approved Pharmaceuticals
• Cesamet – antinausea
• nabilone
• Marinol – antinausea
• synthetic dronabinol (THC); Schedule III
• Dizziness 50%, hallucination 6%, paranoia 5%
• Sativex (Canada) – cancer pain, spasms/spasticity in multiple sclerosis
• 100 µl = 2.7mg THC, 2.5mg CBD
Pertwee RG ed: Handbook of Cannabis, Oxford University Press, 2014.
Sleep
Pertwee RG ed: Handbook of Cannabis, Oxford University Press, 2014.
Science Summary
• CB1 receptors: in Brain
• CB2 receptors: in Immune system
• THC: activates CB1• May improve or worsen seizures, per evidence
• more psychic and anxiety side-effects
• the net effect on different regions of different brains is unique and not predictable
• CBD: not active at CB1• Evidence exists only for anti-seizure properties
• with less psychic changes, may have anti-addiction properties
High-CBD Summary
• Different strains of cannabis:• different levels and proportions of THC & CBD
• Charlotte’s web – high CBD
• Risks of Cannabis: stroke? heart attack? • Need to be studied more formally in our specific
target population
• Drug-CBD interactions exist
• Problem: most can’t wait for the research
• We will have studies on Epidiolex 98% CBD in the upcoming years
Cannabinoids:Miraculous
Claims; Not all tested… yet
http://idrasilrx.com/doctor-information/human-receptor-information/