Effects of Chloroquine and Hydroxychloroquine on the Cardiovascular System - Limitations for Use in the Treatment of COVID-19

Abstract Chloroquine (CQ) and Hydroxychloroquine (HCQ) are antimalarial drugs, with anti-inflammatory properties that justify their use in the treatment of systemic lupus erythematosus and rheumatic diseases. A pandemic caused by the new coronavirus led the entire world's scientific community to look for drugs already available on the market, capable of exercising beneficial actions in the fight against the disease. Preliminary studies in patients, as well as in vitro studies, suggested possible therapeutic effects associated with the use of HCQ and CQ in the treatment of COVID-19. Despite controversies over the effects of these drugs in combating the "cytokine storm" associated with COVID and the dismal of results in different clinical trials in Brazil, their use has been encouraged and several ongoing investigative studies are underway. In addition to the possible beneficial effects on the prognosis of patients with SARS-CoV-2, such drugs include varied effects on the cardiovascular system, ranging from positive developments related to their vasodilator properties to potential negative effects, such as cardiotoxicity. This work presents the main effects exerted by these drugs on the cardiovascular system, in order to contribute to a scientific discussion about the repurposing of these drugs in the context of COVID-19.

Primum non nocere - Are chloroquine and hydroxychloroquine safe prophylactic/treatment options for SARS-CoV-2 (covid-19)?

ABSTRACT Chloroquine (CQ) and its analog hydroxychloroquine (HCQ) were recently included in several clinical trials as potential prophylactic and therapeutic options for SARS-COV-2 infection/covid-19. However, drug effectiveness in preventing, treating, or slowing the progression of the disease is still unknown. Despite some initial promising in vitro results, rigorous pre-clinical animal studies and randomized clinical trials have not been performed yet. On the other hand, while the potential effectiveness of CQ/HCQ is, at best, hypothetical, their side effects are factual and most worrisome, particularly when considering vulnerable groups of patients being treated with these drugs. in this comment, we briefly explain the possible mechanisms of action of CQ/HCQ for treating other diseases, possible actions against covid-19, and their potent side effects, in order to reinforce the necessity of evaluating the benefit-risk balance when widely prescribing these drugs for SARS-COV-2 infection/covid-19. We conclude by strongly recommending against their indiscriminate use.

Ultra-high resolution optical coherence tomography analysis of bull's eye maculopathy in chloroquine users / Análise da maculopatia em bull's eye pela tomografia de coerência óptica de alta resolução em usuários de cloroquina

Purpose: Register and compare anatomical changes, structural and quantitative found in optical coherence tomography Stratus and Topcon 3D in chronic users of chloroquine. Methods: Five patients were diagnosed with toxic "bull's eye" maculopathy was submitted to macular optical coherence tomography examination (Stratus and Topcon 3D). Results: Both tools demonstrated an increase reflectivity of choriocapillaris unit just foveal retinal pigment epithelium atrophy. However, Topcon 3D provided to all patients better description of the line corresponding to the transition between inner and outer segments of photoreceptors. Using the possibility of assembling threedimensional images and subtraction selective retinal layers, we found a lesion with a target that reflects the greater thickness of retinal pigment epithelium in central and parafoveal region that is matched to preserve macular photoreceptors. Conclusion: it was observed better resolution and faster image capture by Topcon 3D than Stratus OCT, that provided more detailed analysis of the line corresponding to transition between outer and inner segment of photoreceptors in macular region. With Topcon 3D, it was possible to evaluate soundly the thickness of retinal pigment epithelium in central and parafoveal region that caused an increase reflectivity of choriocapillaris creating a image with a target unpublished before. .

Objetivo: Comparar e registrar as alterações quantitativas e qualitavivas na tomografia de coerência óptica nos pacientes com uso prolongado de cloroquina. Métodos: Avaliaram-se cinco pacientes com diagnóstico de bull’s eye no exame de tomografia de coerência óptica macular com dois modelos de aparelhos: Stratus e Topcon 3D. Resultados: Ambos aparelhos registraram aumento da refletividade coriocapilar foveal provocada pela atrofia do epitélio pigmentar da retina. Somente o Topcon 3D permitiu melhor visibilização da linha de transição entre o segmento interno e externo dos fotorreceptores. Este aparelho também permitiu a formação de imagens tridimensionais e subtração das camadas retinianas, com registro da diminuição da espessura do epitélio pigmentado da retina na região central e parafoveal macular. Conclusão: Foi possível observar a captação mais rápida e com melhor resolução das imagens geradas pelo Topcon 3D. A diminuição da espessura do epitélio pigmentado da retina, provocando o aumento da refletividade coriocapilar, com a formação de uma imagem linear circular cincundando a fóvea, foi mais detalhado pelos cortes realizados no Topcon 3D. .

Varying Arrhythmias during Single Hospital Stay in a Case of Systemic Lupus Erythematosus.

Cardiac involvement is present in more than half of the patients with systemic lupus erythematosus (SLE). However, studies on the prevalence of arrhythmias in this disease and laboratorial correlations predictive of their development do not exist. Possible pathophysiological mechanisms include autoimmune process, atherosclerosis and adverse effects of the drugs especially chloroquine used for treatment of this disorder. We present a unusual case of SLE with varying arrhythmias during a single hospital stay.