tylenol is the one that's hepatotoxic (spanish for harmful to the liver) - ibuprofen is nephrotoxic (italian for harmful to the kidney) maybe you are mixing up your very similar painkillers. in kiddos it's common to go back and forth between them for pain control, thusly attenuating specific insult to liver or kidney. then there's aspirin, don't give that to kids, that's a whole thing