COMPLEMENTARY THERAPY: Herbal Medicines Cannabis and other herbal medicines Flashcards
what are the three types of cannabinoids?
– Endocannabinoids • Anandamide (AEA) • 2-arachidonoylglyerol (2-AG) – Phytocannabinoids • From plants – Synthetic cannabinoids • E.g. spice, nabilone, K2, dronabinol
what does endocannabinoid system regulate?
– sleep – mood – appetite – memory – reproduction and fertility
what are the two neurotransmittera?
• 2-arachidonoylglyerol (2-AG)
– Present at relatively high levels within the central nervous system
– Responsible for basal endocannabinoid signalling
– Is a much more potent agonist (activator) of CB1 receptors
• Anandamide (AEA)
– Present at very low levels and has a very short half-life
– Formation is induced by stress
– Is much less effective at activating CB1 receptors and can sometimes anatgonise (block) the effects of 2-AG
what are the main ingredients in phytocannabinoids?
tetrahydrocannabindol (THC) and Cannabidiol (CBD)
what is THC?
• Tetrahydrocannabinol – Lipid soluble • Mechanism of action – Partial agonist at cannabinoid receptors • CB1 – CNS CB2 – Immune system • Leads to decreased levels of cAMP – Mild antioxidant
what are the uses of THC/
– Licensed in US weight loss in patients with AIDS
– nausea and vomiting in people receiving chemotherapy
what is CBD?
• Cannabidiol (CBD) – Lipid soluble • Mechanism of action: – alters the shape of CB1 recepto which prevents activation by endocannabinoids. – It does not have any psychoactive effects • Availability – Health food shops • not regulated as a medicine
what are the uses of cbd?
– licensed in US for two rare and severe forms of childhood epilepsy
what are the pharmacokinetics of cannaniboids?
Absorption – Inhalation • Rapid onset and good bioavailability – Oral • Slow onset and poor bioavailability Distribution – Lipid soluble • Rapid accumulation in fatty tissues Metabolism – THC metabolites are active
what are the prescribing laws for cannabis in the UK?
• Prescribing is restricted to those on the GMC specialist register and within their speciality.
– Must have clear published evidence or UK guidelines to support treatment
– Only when clinical need cannot be met by a licensed medicine; and when established treatment options have been exhausted.
– Also need
• authorisation from the medical director
• agreement from the multidisciplinary team, using existing protocols on controlled drugs.
who is authorised to procure unlicensed CBPMs in the UK?
• a) Doctor on the GMC Specialist Register
• b) Specialist Importer with a Home Office import and Domestic licence and MHRA licence
• c) Registered pharmacies or retail pharmacy businesses (with Home Office Domestic licences, where appropriate)
– Some pharmacies will NOT need a domestic licence – as pharmacies and retail pharmacy business are able to produce / supply in accordance with their practice. However, if they are wholesale dealing the policy is that they do need a licence.
• d) Licensed wholesale dealers for supply
what is sativex?
- Patented by GW pharmaceuticals
- Licensed in the UK for moderate to severe spasticity in adult patients with MS
- A natural cannabis product which contains a 1:1 ratio of THC and CBD, and many other cannibinoids
- NICE does not recommend that patients are prescribed Sativex
- The only natural cannabis product licensed for use in the UK
how much does a vial of sativex cost the NHS?
£120 per 10 mL vial
what is dronabinol?
- Synthetic product which is identical to THC
- Produced in UK
- Unlicensed in the UK
- Assigned to schedule 2, prescribed on a named patient basis
- Can be prescribed for nausea and vomiting due to chemotherapy which is unresponsive to conventional antiemetics
what is nabilone?
- Synthetic product structurally similar to THC
- Produced in UK Licensed in the UK
- Assigned to schedule 2,no restrictions on prescribing, GPs can continue prescriptions
- Can be prescribed for nausea and vomiting due to chemotherapy which is unresponsive to conventional antiemetics