Why lupus patients discontinue antimalarials in real life: A 50 years-experience from a reference centre

Because of the efficacy and good safety profile of antimalarials in systemic lupus erythematosus (SLE), hydroxychloroquine (HCQ) is currently recommended in all SLE patients. However, patients' compliance was reported as suboptimal. This study aims to elucidate the reasons for discontinuing antimalarials in a large series of SLE patients followed in a single centre during the last 50 years.

Among all patients diagnosed between 1968 and 2017 at our reference centre, retrospective data were obtained from electronic medical records of SLE patients consecutively visited during 2015-2017 and controlled for at least 1 year. Demographic, clinical, laboratory and therapeutic data at disease onset and during the follow-up in the whole cohort and differences between SLE patients discontinuing and continuing on antimalarials were analysed.

Five-hundred thirty-nine patients followed during a median of 19 years were analysed. Median age at disease diagnosis was 29 years and 91.8% were women. Antimalarials were initiated by 521 (96.7%) patients and 18 (3.3%) cases did not start them mainly because of a quiescent or life-threatening SLE disease. In the 129 (24.7%) patients starting antimalarials with subsequent discontinuation, median treatment duration was 8.4 years. The main reason leading to treatment cessation was drug toxicity in 97 (18.6%) patients, of which macular toxicity was the most frequent adverse effect (n = 80; 15.3%). Treatment was stopped because of patient's preference in 13 (2.5%) cases. The factors independently associated with antimalarial discontinuation were age at the end of follow-up (OR 1.130, 95% CI 1.005-1.269, p = 0.040), duration on antimalarials (OR 0.872, 95% CI 0.841-0.903, p < 0.001), presence of hepatitis C virus infection (HCV) (OR 13.948, 95% CI 1.321-147.324, p = 0.028) and anti-β2-glycoprotein 1 antibodies (OR 2.275, 95% CI 1.146-4.517, p = 0.019).

In our 50 years-experience, almost all SLE patients underwent antimalarials. These drugs are usually stopped because of adverse effects, particularly macular toxicity. After a long-term follow-up, patients' compliance to antimalarials was considerably high in our SLE patients.