The oromucosal spray developed from the major components of marijuana, including tetrahydrocannabinol (THC) and cannabidiol (CBD), in alcohol with a peppermint flavouring, is designed to be administered as a spray under the tongue or on the buccal mucosa to relieve pain in multiple sclerosis. Although the available evidence indicates its efficacy in this respect, some patients develop a sensation of dry mouth5 or a bad taste8 but also – as shown here – stinging and/or mucosal white lesions, probably burns, in a minority. Dry mouth is also a consequence of cannabis and cannabinoids used in other forms.11 Four of eight patients developed oral white lesions which resolved on cessation of spray use, suggesting they were chemical burns. The high alcohol concentration raises concern in relation to chronic oral use and it would therefore be wise to warn against continued spraying on to sore or damaged mucosa, advise that regular oral inspection is mandatory in chronic users and to move to formulation with non-alcohol solutions, despite the lack of evidence implicating alcohol-containing mouthwashes in oral cancer.12
Marijuana in other forms, by comparison with other ‘recreational’ drugs, could be rated to be a relatively safe drug13 but can have adverse effects.14 THC from cannabis enters the bloodstream and exerts its effects on the body via interaction with endogenous receptors. On the CNS, adverse effects can include depression, anxiety and personality disturbances. Marijuana can impair memory and learning, distort perception, cause difficulty in thinking and problem solving and impair coordination, and may trigger psychoses – development of which is often delayed, almost 50% of patients receiving a diagnosis more than a year after seeking treatment for a cannabis-induced psychosis.15Marijuana can also have systemic effects, affecting blood pressure and heart rate and lowering the oxygen-carrying capacity of blood: the risk of myocardial infarction may more than quadruple in the first hour after using it. Babies born to women who used marijuana during pregnancies displayed abnormal responses to visual stimuli, tremulousness and a high-pitched cry.
Smoking marijuana frequently leads to respiratory illnesses such as infections, daily cough and sputum production, and obstructed airways. There have been case reports of upper respiratory tract cancers in young adults who smoke cannabis, but evidence from the few epidemiological cohort studies and case-control studies is inconsistent.16 Patients using marijuana may develop oral leukoplakia,17although tobacco use may contribute to this, and there was concern from some case reports that cannabis use may predispose to oral cancer,18,19 though a large population-based study in USA has essentially discounted this.20 Cannabis smoke may be less carcinogenic than that from tobacco.21
Cannabis abusers also generally have poorer oral health than non-users, have xerostomia, with an increased risk of dental caries and periodontal diseases, and may be prone to oral infections, possibly aggravated by an immunosuppressive effect22,23 (Table 2). Dental treatment of patients using cannabis can result in acute anxiety, dysphoria and paranoiac thoughts, and epinephrine-containing local analgesics may prolong the tachycardia induced by cannabis.24,25
The oromucosal spray developed from marijuana (cannabis) may relieve pain in some chronic diseases, but some patients develop an oral burning sensation, stinging or white lesions, probably burns. Dryness and bad taste have also been recorded. Patients should therefore be sensitised to these effects in relation to chronic oral use. Although the lesions in this study were almost certainly burns due to the alcohol, resolving or improving on discontinuation of use of the medication, the high alcohol concentration used orally raises concern in relation to chronic use, as alcohol may itself have carcinogenic potential, since alcohol may be metabolised by the oral flora to acetaldehyde.26 It is possible that some other constituent such as peppermint (piperitone) might contribute, but the only published report on the oral adverse effects of this was related to orofacial granulomatosis.27
Orofacial lesions are common in people who use psychoactive substances28 and may be seen in topical marijuana use.
2. Gorter R W, Butorac M, Cobian E P, van der Sluis W. Medical use of cannabis in the Netherlands. Neurology 2005; 64: 917-919.
3. Ware M A, Adams H, Guy G W. The medicinal use of cannabis in the UK: results of a nationwide survey. Int J Clin Pract 2005; 59: 291-295.
4. Varma P. Public health issue brief: medical marijuana: year end report-2004. Issue Brief Health Policy Track Serv 2004; 31: 1-9.
5. Rog D J, Nurmikko T J, Friede T, Young C A. Randomized, controlled trial of can nabis-based medicine in central pain in multiple sclerosis. Neurology 2005; 65: 812-819.
6. Blake D R, Robson P, Ho M, Jubb R W, McCabe C S. Preliminary assessment of the efficacy, tolerability and safety of a cannabis-based medicine (Sativex) in the treatment of pain caused by rheumatoid arthritis. Rheumatology (Oxford) 2005; 45: 50-52.
- Wright S, Ware M, Guy G. The use of a cannabis-based medicine (Sativex) in the treatment of pain caused by rheumatoid arthritis. Rheumatology (Oxford) 2006; 45: 781.
- Perras C. Sativex for the management of multiple sclerosis symptoms. Issues Emerg Health Technol 2005; 72: 1-4.
- Perez J. Combined cannabinoid therapy via an oromucosal spray. Drugs Today (Barc) 2006; 42: 495-503.
- Barnes M P. Sativex: clinical efficacy and tolerability in the treatment of symptoms of multiple sclerosis and neuropathic pain. Expert Opin Pharmacother 2006; 7: 607-615.
- Berlach D M, Shir Y, Ware M A. Experience with the synthetic cannabinoid nabilone in chronic noncancer pain. Pain Med 2006; 7: 25-29.
- Cole P, Rodu B, Mathisen A. Alcohol-containing mouthwash and oropharyngeal cancer: a review of the epidemiology. J Am Dent Assoc 2003; 134: 1079-1087.
- Iversen L. Long-term effects of exposure to cannabis. Curr Opin Pharmacol 2005; 5: 69-72.
- Kalant H. Adverse effects of cannabis on health: an update of the literature since 1996. Prog Neuropsychopharmacol Biol Psychiatry 2004; 28: 849-863.
- Arendt M, Rosenberg R, Foldager L, Perto G, Munk-Jorgensen P. Cannabis induced psychosis and subsequent schizophrenia-spectrum disorders: follow-up study of 535 incident cases. Br J Psychiatry 2005; 187: 510-515.
- Hall W, Christie M, Currow D. Cannabinoids and cancer: causation, remediation, and palliation. Lancet Oncol 2005; 6: 35-42.
- Darling M R, Arendorf T M. Review of the effects of cannabis smoking on oral health. Int Dent J 1992; 42: 19-22.
Firth NA. Marijuana use and oral cancer: a review. Oral Oncol 1997;
Rosenblatt K A, Daling J R, Chen C, Sherman K J, Schwartz S M. Marijuana use and risk of oral squamous cell carcinoma. Cancer Res 2004; 64: 4049-4054. Melamede R. Cannabis and tobacco smoke are not equally carcinogenic. Harm Reduct J 2005; 2: 21.
Cho C M, Hirsch R, Johnstone S. General and oral health implications of cannabis use. Aust Dent J 2005; 50: 70-74.
Darling M R, Arendorf T M. Effects of cannabis smoking on oral soft tissues. Community Dent Oral Epidemiol 1993; 21: 78-81.
Gregg J M, Campbell R L, Levin K J, Ghia J, Elliott R A. Cardiovascular effects of cannabinol during oral surgery. Anesth Analg 1976; 55: 203-213.
Horowitz L G, Nersasian R R. A review of marijuana in relation to stress-response mechanisms in the dental patient. J Am Dent Assoc 1978; 96: 983-986. Pikkarainen P H, Baraona E, Jauhonen P, Seitz H K, Lieber C S. Contribution of oropharynx microflora and of lung microsomes to acetaldehyde in expired air after alcohol ingestion. J Lab Clin Med 1981; 97: 631-636.
Patton D W, Ferguson M M, Forsyth A, James J. Oro-facial granulomatosis: a possible allergic basis. Br J Oral Maxillofac Surg 1985; 23: 235-242.
Thavarajah R, Rao A, Raman U, Rajasekaran S T, Joshua E R H, Kannan R. Oral lesions of 500 habitual psychoactive substance users in Chennai, India. Arch Oral Biol 2006; 51: 512-519.
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