Despite repeated emphasis upon the distinction between
dose and dosage, these two terms continue
to baffle us. As we’ve often been told, dose
refers to a specified amount of medication taken at one time.
In the preferred use of dosage, however, the term
refers to the administering of a specific amount, number,
and frequency of doses over a specified period of time. Dosage
implies duration: a “dosage regimen” is a treatment
plan for administering a drug over a period of time. One way
to absolutely never forget the distinction between dose
and dosage is to focus on the meaning of the suffix
–age in dosage. Dose will then be
understood by default.
The ending –age has a number of meanings. For
instance, place or residence (orphanage, a place
that houses orphans); relationship, connection (parentage);
an action (blockage, curettage); a condition
(peerage) and a few others. But the meaning that’s
relevant here is the one that has to do with a collection,
mass, or overall amount. The suffix is added to a singular
noun, which is semantically specific. For instance, driving
to and from work you travel a certain number of miles a day
in your car. However, the number recorded on the odometer
represents the mileage (also spelled milage), that is the
total number of miles the vehicle has traveled up to the present
time. Dose and doses are comparable to mile
and miles, respectively. Dosage is comparable
to mileage. Terms belonging to the same set as dosage
and mileage convey a cumulative effect, meaning that
implicitly or explicitly a chronological element belongs
to the overall sense of the words.
Similarly, a multi-acre farm is plowed acre by acre; and a
certain number of acres may be plowed in one day.
The plurality of acres can of course be called acres.
But the plural can also be expressed as a collective, that
is, as acreage—as in “corn acreage,”
denoting the total number of corn-producing acres on a farm.
Words belonging to the same subset include cordage
(cords or ropes collectively, as in the rigging of a ship);
foliage (all the leaves on a growing plant; root
Latin folium, leaf); leafage, the native English
equivalent of foliage; footage, meaning
1) the total number of feet in a space, as in the “square
footage” of your office, and 2) a length of film; lineage
[pronounced as 2 syllables], also spelled linage,
meaning the total number of written or printed lines in a
text; plumage (the entire covering of feathers on
a bird; root Latin pluma, down); sewage
(the entire amount of liquid and water-borne wastes from households
and industrial plants); sewerage (the entire sewer
network of pipes, etc. used to treat sewage; sewerage
is also sometimes used to mean ‘sewage’); and
tonnage (the total number of tons of freight that
a ship can carry).
Dosage is comparable to acreage, cordage, foliage,
footage, leafage, lineage (linage), linkage (including
its genetics sense), mileage (milage), plumage, rootage,
sewage, sewerage, and tonnage.