President Biden’s physician stopped the commander-in-chief’s use of heart medications Thursday after he began to take Paxlovid to treat COVID-19, White House officials said — despite the fact that doing so elevates the risk of dangerous blood clots. Dr. Ashish Jha, the White House coronavirus coordinator, said at a press briefing that it’s “very standard” to discontinue the medications during a five-day regimen of the antiviral Paxlovid.