Hydroxychloroquine and azithromycin tolerance in haemodialysis patients during COVID-19 infection

Haemodialysis patients are at risk of developing severe forms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection: coronavirus disease 2019 (COVID-19). In March 2020, hydroxychloroquine (HCQ) and azithromycin (AZI) were proposed as potential treatments of COVID-19, but with warnings concerning their possible toxicity. No data are available regarding the toxicity of this treatment in haemodialysis patients.

We report the use of HCQ and AZI in a cohort of COVID-19 haemodialysis patients with focus on safety concerns.

Twenty-one patients received 200 mg HCQ thrice daily during 10 days, and AZI 500 mg on Day 1, and 250 mg on the four following days. HCQ plasma concentrations were within the recommended range (0.1-1.0 µg/mL) in all patients except one, in which maximum concentration was 1.1 µg/mL. HCQ concentration raised until the third day and remained stable thereafter. No cardiac event occurred in spite of progressive lengthening of corrected QT interval (QTc) during the treatment. One patient experienced a long QTc syndrome (QTc >500 ms) without any arrhythmia episode, although HCQ concentration was in the target range. Five (23.8%) patients experienced hypoglycaemia, a well-known HCQ side-effect. SARS-CoV-2 RNA remained detectable in nasopharyngeal swabs for a long time in haemodialysis patients (mean time 21 days).

HCQ and AZI are safe in haemodialysis patients at these doses but can lead to long QTc syndrome and hypoglycaemia. HCQ concentrations were not correlated with side effects. We recommend monitoring of the QTc length throughout treatment, as well as glycaemia. SARS-CoV-2 could persist for longer in haemodialysis patients than in the general population.