I wonder if rapid bacterial cell death would cause someone to be (temporarily) sick from the toxicity of the dead bacteria, in a systemic infection. This can happen with candida die-off from systemic anti-fungal drugs -- I think this was the rationale for FDA non-approval of an antifungal that is used in Europe.
I'm NOT suggesting that Brilacidin wouldn't be approved for this reason, since it would be a transient period of discomfort -- just wondering if this might be a side effect from treatment of a systemic infection, with certain bacteria.