That's an odd argument. If we are talking about a organ safe uncombined dosage of Tylenol or Ibuprofen being 0.4 then I think we are talking about the point just above placebo and bias where something barely has a real effect that should be hard to measure without a high power study. That's saying nothing useful with so few significant figures.

If antidepressants cost less than $4/1000 and acted as an antiinflammatory as their only common side effect then sure I'd consider replacing Ibuprofen as my pain placebo of choice.