You can--and absolutely should--ask the doc or the pharmacist; they will
be happy to give you the info. Also, you
can simply type the name of the med into a google search box, and tons of info will come up.
But first--you have to know the NAME of the drug in question.
And as for what your 'friend may have heard," is this person a doctor or nurse? If not, why are you even listening to him or her?