Re: Covid-19: Lopinavir-ritonavir does not benefit hospitalised patients, UK trial finds
We should not be surprised to see that antiviral drugs have little effect in hospitalised patients.
Antiviral drugs are relatively new (compared to antibiotics); but we have had antivirals for herpes simplex and influenza for many years now. We know that, if they are to be effective, they have to be used early in the course of the disease. Antiviral use in influenza has relatively little effect when given to somebody who is already ill. Given as chemoprophylaxis, however, they are not only given before the onset of symptoms (maximising their efficacy); but they are also effective in reducing the quantity and duration of viral shedding, and thus the infectiousness of cases. This is why they are so valuable when used in care homes, for example.
With Covid-19, we know that the severe forms of disease - the ones responsible for hospitalisation - are triggered by the infection, but are caused by an over-reaction of the immune system; and they occur at a time when most patients are no longer infectious, suggesting that by the time these reactions cause problems, the virus has already been cleared by the immune system.
If this is the case - and the virus, having triggered the immune over-reaction, is no longer present, or important in the ongoing course of the disease - it is hardly surprising that antivirals, at this point in the natural history of the disease, are of little or no value.
Competing interests: No competing interests