Background Dimethyl fumarate(DMF; Tecfidera) is an oral drug approved in Spain since February 2014 for relapsing remitting multiple sclerosis (RRMS). Oral treatments allow patients a better quality of life than injectable treatments, but are not innocuous.

Purpose To assess the safety profile of DMF in RRMS treatment in adult patients in a tertiary hospital.

Material and methods This was an observational and retrospective study of patients from a tertiary hospital who began treatment with DMF between February 2015 and March 2016. The studied variables were: age, sex, previous treatment, safety profile (adverse reactions (AR), suspension or dose reduction) and alternative treatment in the event of suspension of DMF treatment. The information was obtained from outpatient dispensing programme registration (Farmatools). AR reported by patients after clinical interview were collected in each dispensation.

Results Our study included 40 patients diagnosed with RRMS (9 men/31 women) with a mean age of 37.7 years. 15 were treated with DMF as the firstline treatment, and 25 had previously been treated with: intramuscular interferon-beta-1a (5), subcutaneous interferon-beta-1a (11); subcutaneous interferon-beta-1b (3); subcutaneous glatiramer acetate (6); and oral fingolimod (1). 14 patients did not show AR or these were not mentioned in the interview. 26 patients presented AR in the skin (flushing, itching, eczema) and gastrointestinal symptoms (nausea, vomiting, heartburn, stomach-aches) as well as fatigue and others. 69.23% of patients (18) reported skin disturbances (appearing after taking medication and remitting in 3–4 hours), 69.23% (18) gastrointestinal disorders and 19.23% (5) expressed fatigue, especially at the beginning of treatment. 5 patients suffered other AR: changes in blood glucose levels (2), lymphopenia (1), palpitations (1) and urinary tract infection (1). Several patients presented AR in multiple groups. 50% (13) had both skin and gastrointestinal AR, 15.38% (4) gastrointestinal and fatigue, 7.69% (2) had skin reactions and fatigue and 1 patient suffered three types of AR, which led to discontinuation of treatment. 8 patients required temporary dose reduction, mainly due to digestive AR. 1 patient continues with the reduced dose. The treatment was discontinued in 3 patients because of intolerance and in 1 because of failure.

Conclusion DMF is well tolerated. Patients reported mild AR, being more intense as the dose was increased and disappearing with time. However, in some cases they were limiting and did not allow the full dose to be administered or treatment was discontinued. AR are in line with those described in the data sheet and other studies, although increased monitoring is necessary to assess effectiveness and long term safety.

No conflict of interest