Hydroxychloroquine and Cardiotoxicity

Hydroxychloroquine Induced Cardiotoxicity: A Case Series

Hydroxychloroquine (HCQ) induced cardiotoxicity is a rare diagnosis and is often associated with chronic use of the medication. It has been shown that chronic HCQ use is associated with a drug-induced cardiomyopathy mainly driven by acquired lysosomal storage defects leading to hypertrophy and conduction abnormalities. As the only proven treatment is the discontinuation of the offending agent, prompt recognition is required to avoid further exposure to the drug and potential progression of disease. History, physical examination and advanced imaging modalities are useful diagnostic tools, but more invasive testing with an endomyocardial biopsy is required for definitive diagnosis. We present a descriptive case series of ten patients that were diagnosed with biopsy proven HCQ cardiotoxicity.

Advancements on the impact of hydroxychloroquine in systemic lupus erythematosus

Hydroxychloroquine (HCQ) has gained significant attention as a therapeutic option for systemic lupus erythematosus (SLE) because of its multifaceted mechanism of action. It is a lipophilic, lysosomotropic drug, that easily traverses cell membranes and accumulates in lysosomes. Once accumulated, HCQ alkalizes lysosomes within the cytoplasm, thereby disrupting their function and interfering with processes like antigen presentation. Additionally, HCQ has shown potential in modulating T-cell responses, inhibiting cytokine production, and influencing Toll-like receptor signaling. Its immunomodulatory effects have generated interest in its application for autoimmune disorders. Despite its established efficacy, uncertainties persist regarding the optimal therapeutic concentrations and their correlation with adverse effects such as retinal toxicity. Therefore, standardized dosing and monitoring guidelines are crucial. In this study, we provide a comprehensive review of the mechanisms, efficacy, dosing variations, and retinal toxicity profiles of HCQ, which are essential to optimize SLE treatment protocols and ensure patient safety.