More about chloroquine and hydroxychloroquine, CEBM (updated 30th August 2020)

VERDICT The hypothesis that the 4-aminoquinolines chloroquine and hydroxychloroquine may be beneficial in the treatment of COVID-19 is a weak one, based on poor mechanistic reasoning and inconsistent results of studies in vitro, in laboratory animals, and in humans. It is likely that even if chloroquine and hydroxychloroquine are effective in COVID-19, the beneficial effects will be small. The risks of adverse reactions to these drugs may be increased in patients who are acutely ill with severe COVID-19, in many of whom high doses are being used. Macrolide antibacterial drugs, such as azithromycin, clarithromycin, erythromycin, and telithromycin, interact adversely with the 4-aminoquinolines, since both types of drug prolong the electrocardiographic QT interval. The combination increases the risk of the serious ventricular tachycardia called torsades de pointes, which is often fatal. Macrolide antibacterial drugs should be avoided in patients taking chloroquine or hydroxychloroquine. Other drugs that prolong the QT interval should also be avoided or used with care.
Source: Current Awareness Service for Health (CASH) - Category: Consumer Health News Source Type: news