New potential interaction with emergency COVID-19 medicine remdesivir

    Healthcare providers should be aware of a newly discovered potential drug interaction relating to remdesivir, an investigational antiviral granted approval for emergency use during the COVID-19 pandemic.

    The US FDA recently issued a warning about this potential drug interaction with remdesivir, which was granted an emergency use authorisation (EUA) last month for the treatment of hospitalised patients with severe COVID-19 disease.

    Based on data from a recently completed, non-clinical laboratory study, the FDA is revising the fact sheet for healthcare providers that accompanies remdesivir to state that "co-administration of remdesivir and chloroquine phosphate or hydroxychloroquine sulfate is not recommended as it may result in reduced antiviral activity of remdesivir", said the agency.

    The FDA added that it had revised the above-mentioned fact sheet "to clarify dosing and administration recommendations and to provide additional safety data and supporting data from clinical trials conducted by both the National Institutes of Health and the drug sponsor, Gilead Sciences Inc".

    Additional information about possible allergic reactions Footnote 1 has also been added to the fact sheet for patients and caregivers, as well as advice to patients to tell their healthcare providers if they are taking either chloroquine phosphate (also called chloroquine diphosphate) or hydroxychloroquine. The EUA requires that fact sheets regarding use of remdesivir in the treatment of COVID-19 should be made available to healthcare providers plus patients and caregivers − which should include information about potential side effects.

    The agency highlighted that "the safety and efficacy of remdesivir for the treatment of COVID-19 continue to be evaluated, and preliminary clinical trial results have shown that on average, patients treated with remdesivir had more rapid time to recovery".


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      including low BP, increased/decreased heart rate, shortness of breath, wheezing, angioedema, difficulty swallowing, rash, nausea, vomiting, sweating, shivering and respiratory distress.


    1. US Food and Drug Administration. Coronavirus (COVID-19) Update: FDA Warns of Newly Discovered Potential Drug Interaction That May Reduce Effectiveness of a COVID-19 Treatment Authorized for Emergency Use. Internet Document : 15 Jun 2020. Available from: URL:

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    New potential interaction with emergency COVID-19 medicine remdesivir. Reactions Weekly 1810, 3 (2020).

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