Do doctors prescribe brands in America? Here they’ll prescribe you with the working substance, and unless it’s still patented (which most of them aren’t) then you’ll just get offered the cheapest brand at the pharmacy by default.
I guess commercials would still work if you branded yourself hard enough, but our culture is more like the Velcro thing, where when people ask for a “panodil” or a “pinex” they don’t really care if it’s actually a panodil or a pinex as long as it’s a headache pill with that the same sort or working chemical.