Antimalarial drugs touted by the White House as possible COVID-19 treatments looked to be not just ineffective, but downright deadly. I think the quote above i

Antimalarial drugs touted by the White House as possible COVID-19 treatments looked to be not just ineffective, but downright deadly. I think the quote above is what you're referring to. If so, the structure "Not only {small_point}, but {large_point}" is extremely common and used both with negatives and positives.