Hot on the heels of the FDA’s revocation of the emergency use authorization (EUA) of chloroquine phosphate and hydroxychloroquine sulfate for COVID 19, the FDA issued a new release (here) describing the newly discovered drug interaction with Remdesivir and the two drugs that just had their EUA revoked.

According to the release, the Agency is saying, “[B]ased on a recently completed non-clinical laboratory study, the FDA is revising the fact sheet for health care providers that accompanies the drug, 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.”  They do acknowledge that they are not aware of this happening in a clinical setting as this was observed in a laboratory setting, but wanted to alert clinicians.

The Fact Sheet also provides an update on an adverse drug event (potential allergic reaction) involving the use of remdesivir and also advises patients to tell their health care provider if they are taking chloroquine or hydroxychloroquine so that can be factored into an appropriate treatment regimen.  The Fact Sheet can be found here.

New developments on potential COVID 19 treatments and EUAs are coming almost daily.  It’s hard to keep up but we will try to provide the most critical information as it becomes available.