Prevalence of hydroxychloroquine-induced side-effects in dermatology patients: A retrospective survey of 102 patients

Our aim was to assess the prevalence of adverse effects (AEs) pertaining to the use and withdrawal of hydroxychloroquine (HCQ) in dermatological outpatients. We conducted a retrospective study between January 2013 and June 2014 that included consecutive patients currently or previously receiving HCQ seen in our department. AEs were collated using a standardized questionnaire and validated by clinical and laboratory examination. Drug causality was evaluated using the updated French drug reaction causality assessment method. The main evaluation criterion was the prevalence of AEs in which HCQ had an intrinsic imputability score of I>2. We included 102 patients (93 of whom were women, with a median age of 44.5; range: 22-90years). HCQ was given for cutaneous lupus in most cases (n=70). At least one AE was reported for 55 patients. Among the 91 reported AEs, 59 (65%) had an HCQ intrinsic imputability score I>2. AEs were responsible for permanent HCQ discontinuation in 19 cases. Of these, 8 were unrelated to HCQ based on imputability score. The most common AEs associated with HCQ were gastrointestinal and cutaneous signs. Of the 8 patients diagnosed with retinopathy, only 3 were confirmed after reevaluation. AEs associated with HCQ were reported for over 50% of patients and were responsible for permanent HCQ discontinuation in one-third of cases. A more in-depth evaluation of imputability seems necessary, particularly regarding ophthalmological symptoms, since in two thirds of cases the reasons for discontinuation were not related to HCQ.