Dosage Calculation Formulas Flashcards

Study Notes

Dosage Calculation Formulas

Use Formula Method:
Formula: ( \text{Dose Ordered} / \text{Dose On Hand} \times \text{Quantity} = \text{Amount to be Given} )
Denoted as ( D/H \times Q = H )
Use Ratio and Proportion Method:
Formula: ( \text{Dosage on Hand} : \text{Quantity Available} = \text{Dosage Ordered} : X )
Denoted as ( H : Q = D : X )
Use Dimensional Analysis Method:
Formula: ( Q \times C(H) \times D / H \times C(D) \times 1 = X )
Translates units for accurate dose calculation

IV Flow Rate Calculation

Calculate IV flow rate with:
Amount of solution (mL) divided by Hours to infuse equals ( \text{mL/hr} )

IV Administration by Gravity

Formula for drop rate:
( \text{Amount of solution to be given} \times \text{Drop factor} / \text{Total minutes} = gtt/min )

Therapeutic Dose Calculation

Step one: ( \text{Drug dose} \times \text{Patient's weight (kg)} = \text{Patient's dose/day} )
Step two: ( \text{Patient's dose/day} / \text{Number of doses ordered} )

Conversion from mcg/kg/min to mL/hr

Step one: ( \text{Ordered mcg/min} \times \text{Patient's weight (kg)} \times 60 = \text{mcg/hr} )
Step two: ( \text{mcg/hr} / \text{Dose on hand in mcg} \times \text{Quantity} = \text{mL/hr} )

Measurement Conversions

1 kg equals 2.2 lbs
1 gr equals approximately 60 mg/64 mg/65 mg
1 quart equals 1000 mL (1 liter)
1 oz equals 30 mL
1 teaspoon equals 5 mL
1 tablespoon equals 15 mL
1 teaspoon equals 3 tablespoons

Rounding Guidelines

Round capsules and drops to whole numbers; parts of capsules and drops cannot be administered.
Round injectable medications less than 1 mL to hundredths using tuberculin syringe.
Round injectable medications more than 1 mL to tenths using a 3 cc or larger syringe.
Always round at the end of calculations; maintain more decimal places for smaller numbers with a general guideline of hundredths place.

Description

Mastering dosage calculations is essential in healthcare. This set of flashcards covers key formulas used in dosage calculation, including the formula method, ratio and proportion method, and dimensional analysis method. Learn to accurately convert and determine the correct dosages for safe medication administration.