1- 41. VOLUME: APOTHECARY SYSTEM
a. Volume will almost always be expressed in the apothecary system when the
common systems are used. The units of volume in the apothecary system are the fluid
dram (f ), fluid ounce (f ), pint (pt), quart (qt), and gallon (gal). Know the following
relationships between apothecary units:
1 gal =
4 qt
1 gal =
128 f
1 qt
=
2 pt
1 qt
=
32 f
1 pt
= 16 f
b. To convert from the apothecary system to the metric system, you must know
the following factors:
1 gal =
3785 ml
1 qt =
946
ml
1 pt =
473
ml
=
30
ml (29.57)
1 f
1 f
=
5
ml
NOTE: (1)
When the sign appears in the signa of a prescription, it means a
teaspoonful or 5 ml: i = 1 tsp = 5 ml (See the prescription below).
(2)
When the doctor writes for
iv of a liquid preparation, it is taken to
mean fluid iv.
(3)
To fill this prescription, dispense four fluid ounces (120 ml) of
phenobarbital elixir and type: "Take one (1) teaspoonful two (2) times daily" as the
directions to the patient.
MD0802
1-59