There are two methods that are used to calculate a dose. These are the formula
method and the ratio-proportion method. Both use the on hand dose of a med-
ication to determine the desired dose based on the medication prescription.
The formula method and the ratio-proportion method are also used to calcu-
late parenteral medications. Alternatively, parenteral medication can be adminis-
tered through a vein either as a bolus or an infusion. If infusing through an
intravenous line, the nurse must calculate the number of drops per minute the IV
should run to deliver the amount of medication ordered.
We’ll leave the topic of preparing medications and explore medications that
are available in nature in the form of herbs. You’ll learn about herbal therapy in
the next chapter.Quiz
- Prescribed: Duricef 0.4G PO QID. On hand: Duricef 200 mg capsules.
How many capsules do you need?
(a) 1 capsule
(b) 2 capsules
(c) 5 capsules
(d) 20 capsules - Prescribed: Ceclor 150 mg. On hand: Ceclor 300 mg tablets. How many
tablets do you need?
(a) 30 tablets
(b) 5 tablets
(c) 50 tablets
(d) 0.5 tablets - Prescribed: 1000 mL of 0.9% normal saline (NS) intravenously every
8 hours. The intravenous tubing delivers 15 gtts/mL. How many gtts/min
(drops per minute) will be infused?
(a) 31 gtts/min
(b) 44 gtts/min
(c) 25 gtts/min
(d) 28 gtts/min - Prescribed: Diabenese 600 mg. On hand: Diabenese 300 mg tablets. You
need 2 tablets.
(a) True
(b) False
(^122) CHAPTER 7 Dose Calculations