Background Antimalarials represent the cornerstone of SLE treatment, since its uses control clinical manifestations in many patients, prevents disease flare and permits steroid reduction. The aim of this study is to describe the safety profile and the reasons for discontinuation of antimalarials in patients with SLE and determine which factors act as a predictor of drop-out.

Methods A single centre, retrospective, case control study was performed including patients with SLE according to SLICC 2012 criteria. Clinical and demographical variables were collected. Disease activity was measured with clinical, analytical and disease scores.

Results 66 patients were included, 56 patients (84.8%) were females, the median age was 49.3 years (23.4, 76.2). 95.50% of patients were Caucasian. 11 patients (16.7%) had high blood pressure and 6 (9.1%) diabetes mellitus. The disease duration of SLE had a median of 198 months (5.1, 144.9), and median SLEDAI was 3.4 (2–23). 45 patients (68.2%) were taking steroids and its median dosage was 3,6 (1.2, 2.5) mg. 58 patients received antimalarial treatment during their follow-up with a median exposure time of 354 (6, 867) months. 91.2% took hydroxychloroquine (HCQ), 6.9% chloroquine (CQ), and only one patient mepacrine (1.7%). At least one side effect was reported in 22 patients (33.3%) leading to permanent withdrawal in 13 (19.7%): 7 cases of ocular toxicity, 4 intolerance (6,1%), and 2 cases of inefficacy (3%). 45 patients (68.2%) continued antimalarials after introduction. Retinal alterations were not associated with age, disease length and duration of the antimalarial therapy.

Conclusions We observed a similar frequency of antimalarial suspension as reported in other studies. The main adverse events during the therapy were ocular toxicity, but in a percentage of patients remains the main cause of treatment withdrawal.