Background Antimalarials (AMs) have been demonstrated to reduce disease activity and prevent damage accrual in SLE. Recent guidelines advice to prescribe AMs in all patients with SLE. However, AM related retinopathy is a severe complication of AM use with a reported prevalence of about 1% after 5 years of use.
Objectives To investigate the use and reasons for non-use of AMs in the Amsterdam Lupus Cohort, as well as disease related variables associated with non-use. Secondly, to assess the occurrence of severe side-effects due to AM use.
Methods Patients were asked for AM-use at their last visit in our longitudinal cohort study. Reasons for non-use were recorded. Demographic and disease characteristics were compared between users and non-users of AMs. Damage was assessed by SLICC damage index (SDI). Daily dosages of hydroxychloroquine (HCQ) according to lean body weight were calculated. Patient records were checked for the presence of ophthalmologic screening for AM-related retinopathy.
Results Out of 190 SLE patients in our cohort, 139 (73.2%) were using AMs at their last visit, predominantly HCQ (136/139, 97.8%), while 92.1% (175/190) had ever used AMs. Daily dosage of HCQ was 400 mg in 115/136 (84.6%) patients. Patients did not use AMs (n=51) for the following reasons: intolerance (n=16), discontinued without a documented reason (n=11), never initiated (n=9), quiescent disease (n=7), contraindication (n=2), other (n=6). Only one patient discontinued HCQ due to AM-related retinopathy. Another patient discontinued HCQ due to cardiomyopathy, possibly related to HCQ. Compared to AM users, non-users of AMs had a longer disease duration (median (range) 13 (2-35) vs 10 (2-37) years; p=0.004), higher SDI (mean SDI 2.4 ± 2.5 vs 1.2 ± 1.8; p<0.001) and a history of lupus nephritis (47% vs 29.5%; p=0.002). Logistic regression showed that SDI and lupus nephritis, but not disease duration, were independently associated with non-AM use. Ophthalmologic screening was performed in 84.9% (118/139) of patients, of whom 78.4% (109/139) in the past 2 years. According to lean body weight, 119/136 (87.5%) had daily dosages of HCQ above the recommended 6.5 mg/kg body weight.
Conclusions Despite increased awareness of the importance of AM treatment in SLE, there is still room for improvement, especially in patients with lupus nephritis and/or long-standing disease. Daily dosages of hydroxychloroquine often exceeded recommendations from guidelines. However, the occurrence of severe side effects is limited.
Disclosure of Interest None Declared