Cannabis; adverse effects from an oromucosal spray

An oromucosal spray has been developed from the major components of marijuana (cannabis), including tetrahydrocannabinol (THC) and cannabidiol (CBD), in alcohol with a peppermint flavouring, 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 oral burning sensation, stinging or white lesions, probably burns.

To investigate the oral side-effects of oromucosal cannabis spray in multiple sclerosis (MS) patients.

A small open observational study.

A series of nine patients with MS who had been using a marijuana oromucosal spray for at least four weeks, were asked to attend for oral examination. Patients were asked whether they had ever experienced symptoms (dryness; bad taste; stinging) associated with use of the spray. A standard oral examination was carried out using a dental light, and the presence of any mucosal lesions recorded. Where mucosal lesions were present, patients were advised to discontinue the spray and re-attend after four weeks for re-examination. For ethical reasons, biopsies were not undertaken at the first visit.

Of nine patients invited to participate, eight attended. All admitted to a stinging sensation on using the oromucosal cannabis spray, and four had visible oral mucosal white lesions in the floor of the mouth.

Although the white lesions observed were almost certainly burns, resolving or improving on discontinuation of use of the medication, the high alcohol concentration of the oromucosal cannabis spray raises concern in relation to chronic oral use.