Hydroxychloroquine safety when used to treat rheumatic diseases

The Canadian Rheumatology Association has updated its position statement on the safety of hydroxychloroquine in the treatment of rheumatic diseases. Hydroxychloroquine, an antimalarial drug, is a particularly important medication for managing systemic lupus erythematosus (SLE), where it has been shown to improve survival and prevent disease flares. In SLE, it also reduces organ damage, lowers cholesterol, improves glucose metabolism, decreases thromboembolic and cardiovascular events, and improves pregnancy outcomes for the mother and fetus. Hydroxychloroquine is also one of the more commonly prescribed disease-modifying drugs in rheumatoid arthritis. Hydroxychloroquine safety monitoringRetinal toxicity is an important potential side effect of hydroxychloroquine. Major risk factors include duration of use, renal disease and concomitant use of tamoxifen. Retinopathy is irreversible; therefore, early recognition through regular monitoring is important to prevent permanent vision loss. The American Academy of Ophthalmology recommends fundus screening with visual fields plus spectral-domain optical coherence tomography at baseline and after five years of treatment. A baseline fundus examination should be performed to rule out pre-existing maculopathy and annual screening should begin after five years of use in patients without major risk factors. Other uncommon side effects of hydroxychloroquine include skin hyperpigmentation and myopathy, including cardiomyopathy. However, in spite of these potential adverse effects, hydroxychloroquine is considered one of the safest drugs used in rheumatology. Cardiac safety Cardiac toxicity was reported with the use of antimalarial drugs during the COVID-19 pandemic. Concerns were raised about the occurrence of QT prolongation leading to serious arrhythmias (e.g., torsade de pointes) and cardiac arrest. However, during the pandemic, hydroxychloroquine was often prescribed at doses much higher than those used to treat rheumatic diseases. It was frequently used in combination with azithromycin, which can also prolong the QT interval. COVID-19 infection itself can cause arrhythmias and cardiomyopathy, and patients with COVID-19 often have hypokalemia, hypomagnesemia and fever, which can potentiate QT prolongation. With conventional dosing and use in rheumatology practice, cardiac toxicity with antimalarials is rare, with QT interval prolongation occurring in only 0.7% of patients with SLE. The prevalence of conduction abnormalities in patients with SLE taking hydroxychloroquine is similar to that seen in a healthy population. Possible risk factors for cardiotoxicity in patients receiving hydroxychloroquine include older age, pre-existing cardiac disease and renal insufficiency. Drug interactions Therapeutic doses of hydroxychloroquine for rheumatic diseases generally do not result in clinically relevant drug interactions. However, hydroxychloroquine has been associated with prolongation of the QT interval when used in combination with certain medications; therefore, it is important to recognize significant drug interactions. Most antidepressants (bupropion, citalopram, escitalopram, duloxetine, fluoxetine, mirtazapine, paroxetine, sertraline, trazodone, venlafaxine) seem to only mildly prolong the QT interval (within normal ranges) when used concurrently with hydroxychloroquine and, therefore, are likely safe. SummaryThe Canadian Rheumatology Association concludes that the use of hydroxychloroquine to treat rheumatic diseases is generally safe when prescribed appropriately and when patients are monitored by a rheumatologist. The significant benefits of hydroxychloroquine, particularly in SLE, definitely outweigh its risks.Reference:Canadian Rheumatology Association. Position statement on the safety of hydroxychloroquine in the treatment of rheumatic diseases. Version: 2.0 December 3, 2024. Published online March 2025. (accessed April 22, 2025).

Hydroxychloroquine safety when used to treat rheumatic diseases

Register for free access or login.

Related Topics

Business Topic