Thank you for your post.
Yours is a very interesting question- one without very good clinical science, hence what I'll say is based on our clinical practice.
It's reassuring that your patient has three different PIs with "maximal response". In such cases, I'll tend to choose the medication with the lowest fold change (FC) below the lower clinical cut off. Based on this theorem, IDV/r could be more potent for the virus than LPV/r; however, the relative differences in FC, in my opinion, are relatively small and are negated by the large differences in the tolerability of the two PI options. Hence, I'd probably pick the LPV/r option.
What a significant difference is not entirely clear, but if one drug was at normal (~1.0) or hypersusceptible (FC ~0.25) ranges, it's my hunch that this would be superior to a drug with a FC or 5.0 or 7.0. Hence, it's multiple factors, drug tolerability, the absolute FC and the relative differences between the absolute FC and the lower cut off that influence the choice in medications.
I hope that you find this discussion helpful,
BY
