Medication sparing after medical cannabis initiation: A case study of a chronic pain patient in Project Twenty21

Abstract

Prescribed cannabinoids are legal in the UK and are increasingly being used for a variety of conditions, with one of the most frequent conditions being chronic pain. Within this cohort, there is developing evidence that cannabis-based medicinal products are associated with opioid and other medication sparing. However, at present, the National Institute for Health and Care Excellence (NICE) does not recommend the prescription of cannabis-based medicinal products to treat chronic pain due to the lack of randomised controlled trial evidence for this condition. Here we present a case study of a 61-year-old woman with idiopathic small fibre neuropathy, who was prescribed the gabapentinoid pregabalin, in combination at different times with various other agents including amitriptyline, duloxetine, lamotrigine, meloxicam and topical capsaicin, over a 17-year period for the associated neuropathic pain. Although her pain was relatively well controlled, the patient reported hearing loss, sleepiness, tinnitus, confusion and worsening anxiety possibly as a result of prolonged pregabalin use. Efforts were made to reduce the pregabalin dose but any attempts to reduce below a total daily dose of 350 mg resulted in unacceptable pain for the patient. In 2021, the patient was enrolled in Project Twenty21, the UK's first medical cannabis registry, and prescribed full plant extract delta-9-tetrahydrocannabinol 10 mg: cannabidiol 15 mg/mL of oil, prescribed at a dose range of 0.1–0.5 mL twice daily. As a result, the patient managed to reduce her pregabalin down to 37.5 mg total daily dose. The patient now feels she has ‘been given a second chance at life’ and her husband describes her as ‘a new woman’. This patient feels that she is in a position to finally stop treatment with pregabalin, as a result of medical cannabis controlling her pain. Highlighting the potential benefits of cannabis-based medicinal products to treat chronic pain, our case study indicates the value of including real-world evidence when assessing the benefits and safety of cannabis-based medicinal products.