covid news, page-32

Just doing a bit of reading and far, very very far from understanding or comprehending the science behind this (my general stocks are mining), but looks like Merck is toast ( or at least much less affective) and Pfizer drug must be taken with Ritonavir which seems to be the drug that made lopinavir drug fail as it was boosted with Ritonavir which has a major drug to drug interaction with a lot of other drugs, which seems to have a greater side affect on the older population.(possibly as they require more other drugs?)
For somebody with some more understanding/knowledge than me, am i correct in this understanding? And why would this new combination be any different, as issue seemed to be Ritonavir? Do we know if BIT's has to be teamed with another drug?
If this has been answered before apologies, and hope you can direct me to post.
Cheers