80 mg = 60 mg
2 ml X ml
80X = 120
X = 1.5 ml
b. Reconstitution of Medications for Injection.
(1) Some medications will become unstable in solution over time. You may
see these medications manufactured as dry powders.
(2) Prior to administration of these medications, an appropriate diluent
(sterile water, normal saline, and so forth) must be added. The term used to describe
the process of adding the diluent to the medication is reconstitution.
(3) Usually the volume of the diluent is expanded somewhat when added to
the dry powder. For example, when 2 ml of diluent are added to a dry vial of 1 gram of
Mefoxin, the resulting withdrawable volume is 2.5 ml.
(4) The directions for reconstitution of a medication may list a number of
different amounts of diluent, each resulting in a different concentration. If that is the
case, choose a concentration, which would provide an appropriate volume for the
injection. When selecting a concentration, keep in mind that no more than 3-4 ml
should be injected into one I.M. site. However, it may be necessary to divide the dose
and inject it into two different sites.
EXAMPLE: The order is to give 300,000 units of Penicillin G Potassium I.M.
A concentration of 200,000 units/ml should be used. The
medication on hand is in a 1,000,000 unit vial. How many ml
will you give? (Directions for reconstitution are listed below.)
1,000,000 unit vial:
Diluent to be Added