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Home , Effects of cannabis

THE TRUTH BEHIND THE HEADLINES

Simerdip Kaur takes a look at the latest ophthalmology-related news stories and asks which are based on facts and which are ‘fake news’.

IOP and another with no change [2]. However, synthetic δ9THC, so that both compounds form these effects were short lasting, between three one semifluorinated alkane, comprising a liquid to four hours, and further hindered by the vehicle and a receptor binding development of tolerance. Moreover, a patient to treat neuropathic pain associated would have to smoke up to 3000 joints per with DED [8]. Headline: year at a significant cost of several thousand In the UK, is a class B and pounds, notwithstanding the side-effects of lung banned from recreational use, however, Another plant-based damage from the smoke inhalation but also cannabis-based products for medicinal use remedy for the eye? the detriment to cognitive function and the risk can be prescribed by doctors on the specialist of drug-induced psychosis [3,4]. Nevertheless, register on a named patient basis following a this preliminary publication led to the victory legislative change in 2018 [9]. Subsequently for a patient in Washington several years later the National Institute for and Care against the supreme court to be the first legal Excellence (NICE) has approved , a user of for his glaucoma. The medical synthetic δ9THC for intractable chemotherapy- marijuana movement is believed to have induced nausea and vomiting; Sativex hat do the nicknames Mary Jane, stemmed from here [5]. (Nabiximol), an oral mucosal spray with equal 9 tea, and 420 all have in common? Numerous other studies soon followed, ratios of δ THC to CBD for multiple sclerosis They refer to marijuana of course! exploring various methods of administering related spasticity; and Epidyolex (CBD), an oral WIf, like me, you were oblivious then marijuana to examine its effect on IOP, including solution for children with Lennox-Gastaut and perhaps this article is worth a read. tablets and intravenous routes. Even cannabis Dravet syndrome related epilepsy [10]. These Marijuana is a mixture of the dried flowers, eye drops which would seem the most obvious developments represent a small but significant leaves and tops of the cannabis plant indigenous route of delivery was unsuccessful due to its step towards the acceptance of medical to eastern Asia. For centuries, it’s been used lipophilic nature, rendering it unsuitable for cannabis as a treatment and will likely propel in religious and spiritual ceremonies, for water-based administration. Oil based vehicles more in this area of pharmacotherapy. healing purposes and as a form of psychotropic have been trialled with no success and instead References diversion. Of the many hundred compounds in cause irritation of the ocular surface. Neither 1. Tomida I, Pertwee RG, Azuara-Blanco A. the plant, delta-9- (δ9THC) of these modes of administration produced and glaucoma. Br J Ophthalmol 2004;88:708-13. and (CBD) are the two main - sustainable effects and were inferior compared 2. Hepler RS, Frank IR. Marihuana and intraocular like chemicals known as cannabinoids, i.e. they to the other pharmaceutical agents available at pressure (letter). JAMA 1971;217:1392. are solely composed of carbon, oxygen and the time. Concurrently, research on this topic has 3. Lieberman MF. “Recredicinal” Marijuana. Am J hydrogen molecules [1]. The former is known for Ophthalmol 2017;177:xv-xviii. since dwindled away. 4. Novack GD. Cannabinoids for treatment of glaucoma. its psychoactive, whilst the latter for its relaxant, There is, however, potential for its use in Curr Opin Ophthalmol 2016;27(2):146-50. effects on the nervous system. The human body ocular surface pain and inflammation. In a 5. Graul TA. Marijuana and Glaucoma. Glaucoma Today also produces its own endogenous cannabinoids mouse model of autoimmune uveitis (Xu et al. March/April 2018 [online]. which are lipid derivatives such as 2017), a synthetic CB2R selective was 6. Toguri JT, Caldwell M, Kelly MEM. Turning down the thermostat: modulating the (arachidonoyl ethanolamide) and 2-arachidonoyl delivered systemically and initiated antigen in ocular Inflammation and pain.Front Pharmacol glycerol (2-AG) and 2-arachidonyl glyceryl ether suppression, impaired leucocyte response and 2016;7:304. (noladin) that act as neurotransmitters [1]. Both generation of pro-inflammatory cytokines in. In 7. Thapa D, Cairns EA, Szczesniak A, et al. Cannabinoids 8 endogenous and exogenous cannabinoids act another mouse model, topical application of a δ THC, CBD, and HU-308 Act via distinct receptors to reduce corneal pain and inflammation.Cannabis and on the endocannabinoid receptors consisting of different CB2R agonist decreased intraocular Cannabinoid Research 2018;3(1). cannabinoid 1 (CB1R) and cannabinoid 2 receptor inflammation by more than conventional 8. Steven P, Scherer D, Krösser S, et al. Semifluorinated (CB2R). CB1 is mainly found in the central steroids and non-steroidal anti-inflammatories alkane eye drops for treatment of dry eye disease—a nervous system (CNS) but also in the lung, heart, (NSAIDs) [6]. Additionally, a separate group prospective, multicenter noninterventional study. J Ocul Pharmacol Ther 2015;31(8):498-503. urogenital, gastrointestinal, peripheral δ8 demonstrated application of THC (instead 9. NHS England and NHS Improvement. Cannabis-based 9 and the eye [1]. In the eye, CB1R have been of δ THC as it is more stable) and CBD reduced products for medicinal use. 31 October 2018: https:// isolated from the cornea, ciliary epithelium, the pain score following capsaicin induced www.england.nhs.uk/wp-content/uploads/2018/10/ trabecular meshwork, Schlemm’s canal, ciliary hyperalgesia on mice corneas via modulation letter-guidance-on-cannabis-based-products-for- medicinal-use.pdf (Last accessed April 2020) muscle, ciliary body, blood vessels and in the at CB1R and serotonin 1A receptor (5-HT ) [7]. 1A 10. National Institute for Health and Care Excellence (2019). retina. CB2R on the other hand are involved More promisingly, a potential breakthrough Cannabis-based medicinal product (NICE guideline in modulating cytokine release as part of the for cornea neuropathic pain sufferers comes in NG144): https://www.nice.org.uk/guidance/ng144 (Last immune system and can be found on leucocytes, the form of perfluorohexyloctane (F6H8). It is accessed April 2020) tonsils and the spleen [1]. It is unsurprising then from a family of semifluorinated alkanes (SFAs) that numerous researchers have sought to characterised by their colourless and inert non- investigate the therapeutic effects of cannabis aqueous lipophilic liquid nature, low surface SECTION EDITOR on the human body alongside the parallel illicit and interface tension, is naturally preservative trials by its recreational users. free and a non-blurring wetting agent. Professor In 1971, the use of marijuana for lowering Steven from Cologne, Germany and his team of intraocular pressure (IOP) was first described by researchers trialled the use of F6H8, marketed Simerdip Kaur, Hepler and Frank [2]. They recruited 11 healthy as NovaTears®, in a prospective observational Ophthalmology Specialty young men between the ages of 21 to 43 without study of 25 patients with evaporative dry eye Trainee Year 3, glaucoma and provided each of them with 2g disease (DED) [8]. They reported a satisfactory KSS Deanery, UK. of marijuana containing 0.9% THC through ice- safety profile and improvement in patients with E: simerdip.kaur@hotmail. cooled water pipe and demonstrated a decrease mild to moderate disease. The researchers hope com in IOP between 16% and 45% in nine of them, that the success of F6H8 in DED will result in its with one subject experiencing a 4% increase in use as part of a phase 1 study for – a

Eye News | JUNE/JULY 2020 | VOL 27 NO 1 | www.eyenews.uk.com