2 Medication Dosage Calculations Free Online FlashCards

What does a medication dosage calculation determine?

It converts a prescribed dose into the amount available to administer, such as tablets or milliliters.

What should you identify before calculating a medication amount?

Identify the medication, prescribed dose, route, and available strength or concentration.

What additional details should you check for an injectable product?

Check the vial strength, route, diluent and reconstitution directions, final concentration, and relevant storage instructions.

How many milligrams are in $1\,\text{g}$?

$1\,\text{g}=1{,}000\,\text{mg}$. Convert units when the order and product label use different dose units.

How does dimensional analysis help calculate an administration amount?

Arrange the dose and conversion factors so matching unwanted units cancel, leaving only the desired administration unit.

What is a repeatable sequence for a dosage calculation?

State the amount and unit needed, write the ordered dose and labeled strength, arrange factors so units cancel, calculate, and check the result. Round only as directed.

The order is $500\,\text{mg}$; tablets contain $250\,\text{mg}$ each. How many tablets?

$500\,\text{mg}\times\frac{1\,\text{tablet}}{250\,\text{mg}}=2\,\text{tablets}$ per dose.

The order is $250\,\text{mg}$; liquid contains $125\,\text{mg}$ per $5\,\text{mL}$. What volume is needed?

$250\,\text{mg}\times\frac{5\,\text{mL}}{125\,\text{mg}}=10\,\text{mL}$ per dose.

What should you use to measure an oral liquid medication?

Use a metric dosing device; household spoons can cause measurement errors.

An injection is labeled $100\,\text{mg/mL}$; the order is $75\,\text{mg}$. What volume is needed?

$75\,\text{mg}\times\frac{1\,\text{mL}}{100\,\text{mg}}=0.75\,\text{mL}$.

Which concentration should you use after reconstituting a medication?

Use the resulting concentration stated for the prepared product, not merely the volume of diluent added.

A prepared solution contains $250\,\text{mg/mL}$; the order is $375\,\text{mg}$. What volume is needed?

$375\,\text{mg}\times\frac{1\,\text{mL}}{250\,\text{mg}}=1.5\,\text{mL}$.