Drug, prescription

A drug requiring a prescription, as opposed to an over-the-counter drug, which can be purchased without one.

The word 'prescription' comes from the Latin 'praescriptus' compounded from 'prae', before + scribere, to write = to write before.

Historically, a prescription was written before the drug was prepared and administered.</P> A prescription has several parts.

There are:</P> > >The superscription (or heading) with the symbol R or Rx which stands for the word Recipe, meaning (in Latin) to take; >The inscription which contains the names and quantities of the ingredients; >The subscription or directions for compounding the drug; and >The signature which is often preceded by the sign s.

Standing for signa, mark, giving the directions to be marked on the container.</LI></UL> Seen on a prescription, b.i.d.

Means twice (two times) a day.

It is an abbreviation for 'bis in die' which in Latin means, not too surprisingly, 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:</P> > >q.d.

(qd or QD) is once a day; q.d.

Stands for 'quaque die' (which means, in Latin, once a day).

>t.i.d.

(or tid or TID) is three times a day ; t.i.d.

Stands for 'ter in die' (in Latin, 3 times a day).

>q.i.d.

(or qid or 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, '2 caps q4h' means 'Take 2 capsules every 4 hours.'</LI></UL>