Sunday, October 14, 2007
q.d. (on prescription)
qd can be seen on a prescription. This can also be written with periods, as q.d. This means "once a day" (from the Latin quaque die). The abbreviation is sometimes written without a period in capital letters as "QD". It is one of a number of hallowed abbreviations of Latin terms that have been traditionally used in prescriptions to specify the frequency with which medicines should be taken.