Evidence review for chronic pain: Cannabis-based medicinal products: Evidence review B

Chronic pain has recently been defined by the ICD-11 as pain that persists or recurs for longer than 3 months. Chronic primary pain is defined as pain in one or more anatomical regions that persists or recurs for longer than 3 months and is associated with significant emotional distress or functional disability. Chronic secondary pain syndromes are linked to other diseases as the underlying cause, where pain becomes a problem in its own right. In practice, the division between acute and chronic pain can be difficult to establish. This is particularly true in children and young people, and the committee felt that the looser (non-temporal) term ‘persistent pain’ is more commonly used in this group. According to the British Medical Association briefing paper chronic pain: supporting safer prescribing of analgesics, chronic pain affects about 13% of adults in the UK, and about 8% of children experience severe pain. NICE has published a summary on the evidence base on medicines optimisation in chronic pain. A NICE guideline on chronic pain: assessment and management is in development. This guideline is intended to be used alongside existing NICE guidance for specific conditions that cause pain, including headaches, low back pain and sciatica, rheumatoid arthritis, osteoarthritis, spondyloarthritis, endometriosis and irritable bowel syndrome. The aim of this review was to find out how effective cannabis-based medicinal products are in managing chronic pain, particularly when conventional treatment options have failed or not been tolerated. The review looked into the safety profile (including complications and contraindications) and examined what individual patient requirements, treatment durations, reviewing and stopping criteria need to be considered when prescribing cannabis-based medicinal products. Chronic pain is common in the UK general population but has a heterogeneous aetiology. A recent epidemiological study found that roughly 43.5%, 28 million people in the UK general population were expected to have “severe and chronic pain that is unresponsive to treatment”. Treatment options vary widely depending on the cause of the pain but their effectiveness and side effects vary widely and there is very significant unmet clinical need in the population group whose pain is not adequately controlled by these conventional options. Some chronic pain patients self treat with cannabis based products purchased as health food supplements or online and there is widespread interest in whether Cannabis Based Medicinal Products (CBMPs) should be prescribed on the NHS. However, it is currently very rare for patients with chronic pain to be treated with CBMPs on the NHS. The CBMPs that are currently on the market could cost several thousand pounds per patient per year, based on publicly available sources for price. This, along with the considerations above meant that the potential resource impact of a positive recommendation in this area could be extremely high. The committee therefore prioritised this question for de novo economic modelling as any positive recommendation would need to be underpinned by robust health economic evaluation.