When should I use throughout the years and over the years? This is my sentence: "Use of migraine drugs remained constant throughout the years" What I want to say is that the use of migraine drugs is actually the same year to year.
It's always seemed to me that "throughout the years" implied persistence or a sense of static: "Throughout the years, he kept searching but never found her."
"Over the years" seems to me to imply a slow change: "Over the years, he grew pessimistic about finding her and eventually gave up the search."
I think you answer your own question. Neither of the options you are querying says what you seem to want to say (according to your final sentence) -
"The use of migraine drugs has remained constant since (the date they were introduced)"