President Donald Trump has received a combination of powerful drugs to battle his Covid-19 infection that may never have been prescribed together to an individual patient: the antiviral remdesivir, a coronavirus antibody cocktail and the steroid dexamethasone.
The decision to administer such a drastic combination of treatments might be a sign that Mr Trump is more seriously ill than his personal physician Sean Conley and the White House medical team have admitted. Alternatively, Mr Trump may have demanded to receive as many drugs as possible to speed his recovery. Either way, the use of the experimental treatments will have required a careful weighing of the risks, given the possible side-effects and the chance of adverse interactions between the different chemicals.
On Friday Mr Trump started a five-day course of intravenous injections of remdesivir, an antiviral drug produced by the US biotech company Gilead Sciences. It works by blocking an enzyme that some viruses need to replicate.
Remdesivir was originally developed to treat the Ebola virus but clinical trials have shown some effectiveness in Covid-19 patients who are moderately ill, speeding up their recovery.