Dimethyl fumarate (Tecfidera, Biogen Idec) derives from fumaric acid, promotes anti‑inflammatory activity and can inhibit expression of pro‑inflammatory cytokines and adhesion molecules. Dimethyl fumarate has a UK marketing authorisation for 'the treatment of adult patients with relapsing‑remitting multiple sclerosis'.
The summary of product characteristics lists the following adverse reactions for dimethyl fumarate: 'gastroenteritis, lymphopenia, leukopenia, hypersensitivity, burning sensation, flushing, hot flush, diarrhoea, nausea, abdominal pain upper, abdominal pain, vomiting, dyspepsia, gastritis, gastrointestinal disorder, pruritus, rash, erythema, proteinuria, feeling hot, ketones measured in urine, albumin urine present, aspartate aminotransferase increased, alanine aminotransferase increased and white blood cell count decreased'. For full details of adverse reactions and contraindications, see the summary of product characteristics.
Dimethyl fumarate is taken orally. The recommended dosage is 120 mg twice daily in the first week of treatment and 240 mg twice daily thereafter. The frequency of flushing and gastrointestinal adverse reactions may be managed by temporarily (up to a month) reducing the dosage to 120 mg twice daily. The prices of a pack of 120‑mg tablets (14 tablets per pack) and 240‑mg tablets (56 tablets per pack) are £343 and £1,373 respectively (excluding VAT; manufacturer's submission). The manufacturer of dimethyl fumarate has agreed a patient access scheme with the Department of Health, with a simple discount applied at the point of purchase or invoice. The level of discount is commercial in confidence. The Department of Health considered that this patient access scheme does not constitute an excessive administrative burden on the NHS.