Essential practice updates supported by Pemason Pharmaceuticals Ltd
[FDA Drug Safety Communication, April 24, 2020] – The U.S. Food and Drug Administration (FDA) is aware of reports of serious heart rhythm problems in patients with COVID-19 treated with chloroquine or hydroxychloroquine, often in combination with azithromycin and other QT prolonging medicines. The agency is reminding healthcare professionals and patients that chloroquine and hydroxychloroquine have not been shown to be safe and effective for treating or preventing COVID-19. They are being studied in clinical trials for COVID-19 and have limited use under Emergency Use Authorization (EUA) for treatment of the virus only in hospitalized patients with careful heart monitoring.
Chloroquine and hydroxychloroquine can cause abnormal heart rhythms such as QT interval prolongation and a dangerously rapid heart rate called ventricular tachycardia. These risks may increase when these medicines are combined with other medicines known to prolong the QT interval, including the antibiotic azithromycin, which is also being used in some COVID-19 patients without FDA approval for this condition. Patients who also have other health issues such as heart and kidney disease are likely to be at increased risk of these heart problems when receiving these medicines.
FDA-approved indications for chloroquine and hydroxychloroquine include treatment and prophylaxis of malaria; hydroxychloroquine is also approved for autoimmune conditions such as chronic discoid lupus erythematosus, systemic lupus erythematosus in adults, and rheumatoid arthritis.
Patients who are on chloroquine or hydroxychloroquine for the approved indications are being advised to continue taking their medicine as prescribed. The benefits of these medicines outweigh the risks at the recommended doses for these conditions. Avoid buying medications from unauthorized or unregistered premises.
Healthcare professionals should be aware of adverse effects associated with chloroquine or hydroxychloroquine:
- QT prolongation
- increase the risk of QT prolongation in patients with renal insufficiency or failure
- increase insulin levels and insulin action causing increased risk of severe hypoglycemia
- cause haemolysis in patients with Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency
- interact with other medicines that cause QT prolongation even after discontinuing the medicines due to their long half-lives of approx. 30-60 days
Patients being prescribed chloroquine or hydroxychloroquine should be monitored closely including baseline ECG, electrolytes, renal function and hepatic tests.