b.i.d. (on prescription):Seen on aprescription,b.i.d.means twice (two times) a day. It is an abbreviation for "bis in die" whichinLatin means twice a day. The abbreviation b.i.d. is sometimes written without a period either in lower-case letters as "bid" or in capital letters as "BID". However it is written, 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.
Other examples include:
- q.d. (qd or QD) is once a day;q.d.stands for "quaquedie" (which means, in Latin, once a day).
- t.i.d. (ortidor TID) is three times a day ; t.i.d. stands for "ter in die" (in Latin, 3 times a day).
- q.i.d. (orqidor QID) is four times a day; q.i.d. stands for "quater in die" (in Latin, 4 times a day).
- q_h: If a medicine is to be taken every so-many hours, it is written "q_h"; the "q" standing for "quaque" and the "h" indicating the number of hours. So, for example, "2capsq4h" means "Take 2 capsules every 4 hours."
