What does qd on a prescription mean?
QD is Latin for "quaque die" which means once a day. For
example, if your prescription says PO QD it means you are suppose
to take your medications by mouth once a day. There is another
abbreviation that can be confused with QD, which is QID. QID is
Latin and stands for "quater in die" which means four time a day.
For example, if your prescription says PO QID it means you are
suppose to take your medications by mouth four times a day.