Long-term evaluation of antimalarials in a Dutch SLE cohort: intolerance and other reasons for non-use

Antimalarials (AMs) have been demonstrated to reduce disease activity and prevent damage accrual in SLE. Recent guidelines advise prescribing AMs in all patients with SLE. We present data from the Amsterdam Lupus Cohort on use, reasons for non-use, and dosage related intolerance of AMs, as well as disease related variables associated with non-use.

AM use was assessed in all our SLE patients included in a longitudinal cohort study. Demographic and disease characteristics were compared between users and non-users of AMs. Daily dosages of hydroxychloroquine (HCQ) according to lean body weight were calculated.

Out of 190 SLE patients in the cohort, 139 (73.2%) were using AMs during 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. According to lean body weight, 119/136 (87.5%) had daily dosages of HCQ above the recommended 6.5 mg/kg. 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. Non-use of AMs was associated with a longer disease duration, higher damage accrual and a history of lupus nephritis.

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, but are generally well-tolerated.