I use the American brand names when talking about meds on the internet.
I’ve never taken trade-name Tylenol, Benadryl, Advil (without pseudoephedrine), Xanax, Effexor, Prozac nor Klonopin.
But those are the names I’d use when discussing them to “blend in”. If I start talking about panado or rivotril I may cause confusion. The API names are also just a fucking mouthful.