[gattilorenz]

"Why don't these people use the more universal name cookies and instead refer to them as biscuits?"

In Europe it's paracetamol, in the US is acetaminophen, both represent the same thing and are not ambiguous. Plus, it's literally mentioned in the 1st paragraph, together with the brand name Tylenol.

In the Netherlands it's sometimes informally called "aspirin", even though that's a different chemical altogether. In Italy, the brand name Tachipirina is often used.

[piperswe]

In the US as well, it's not too uncommon for "aspirin" to be used (especially by older folks) as a generic term for OTC painkillers. When someone says to "take an aspirin," they typically mean acetaminophen or ibuprofen, and probably don't know or care about the difference between the three.