Scribd
Upload
75 views3 pages

Nursing Drug Calculation Guide

The document provides examples for calculating various drug dosages and intravenous (IV) infusion rates. It outlines formulas for [1] calculating tablet dosages based on desired dosage and stock strength, [2] calculating mixtures and solutions by dividing desired dosage by stock strength and multiplying by stock volume, [3] calculating IV rates in mL per hour or minute by dividing total IV volume by time, [4] calculating IV rates in drops per minute by multiplying total volume divided by time by drop factor, and [5] calculating remaining IV infusion time in minutes by multiplying volume remaining divided by drops per minute by drop factor. The document aims to review drug calculation formulas and examples to correctly determine drug dosages and IV infusion rates.

Uploaded by

Renie Serrano
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as DOCX, PDF, TXT or read online on Scribd
75 views3 pages

Nursing Drug Calculation Guide

The document provides examples for calculating various drug dosages and intravenous (IV) infusion rates. It outlines formulas for [1] calculating tablet dosages based on desired dosage and stock strength, [2] calculating mixtures and solutions by dividing desired dosage by stock strength and multiplying by stock volume, [3] calculating IV rates in mL per hour or minute by dividing total IV volume by time, [4] calculating IV rates in drops per minute by multiplying total volume divided by time by drop factor, and [5] calculating remaining IV infusion time in minutes by multiplying volume remaining divided by drops per minute by drop factor. The document aims to review drug calculation formulas and examples to correctly determine drug dosages and IV infusion rates.

Uploaded by

Renie Serrano
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as DOCX, PDF, TXT or read online on Scribd
You are on page 1/ 3

Ateneo De Naga University

Naga City
College of Nursing

Review on Drug Calculations (SDL)


Renie Serrano

Formulas

a. Calculating tablet dosages.

Example:

The patient is ordered to have 2 g of potassium chloride. The drug is available in 500 mg tablets.
How many tablets should be given?

Convert 2 g to mg = 2 x 1,000 = 2,000 mg

Desired dosage ÷ stock strength = number of tablets

2,000 mg ÷ 500 mg = 4 tablets

b. Calculating mixtures and solutions

- Desired dosage ÷ stock strength x stock volume = amount of solution to be given

Example:

The physician orders 375 mg of cefuroxime for the patient. The drug is available in 750 mg vial.
You plan to dilute it in 10 mL of sterile water. How much should you give to your patient?

[Desired dosage ÷ stock strength] x stock volume = amount of solution to be given

[375 mg ÷ 750 mg] x 10 mL = amount of solution to be given

0.5 mg x 10 mL = 5 mL

c. Calculating IV rate -ml/per and minute

- Total IV volume ÷ time (hour or minute) = mL per hour or minute

Example:
Ateneo De Naga University
Naga City
College of Nursing

Review on Drug Calculations (SDL)


Renie Serrano

You are going to start IV infusion with Plain Lactated Ringer’s Solution 1 L. By regulating it for 11
hours, how much fluid are you going to infuse per minute?

Total IV volume ÷ time (hour or minute) = mL per minute

1 L ÷ 11 hours = mL per minute

[1 L x 1,000] ÷ [11 hours x 60] = mL per minute

1,000 mL÷ [11 hours x 60] = mL per minute

1,000 mL ÷ 660 = 1.5 mL per minute

d. Calculating IV rate- drops per minute

- [Total IV volume ÷ time (minute)] x drop factor = drops per minute

Example:

You are going to regulate D5 0.9 NaCl 500 mL solution for 7 hours. The macrodrip used has 15-
drop factor. You should regulate the IV fluid for how many drops per minute?

[Total IV volume ÷ time (minute) ] x drop factor = drops per minute

[500 mL ÷ 7 hours] x 15 = drops per minute

[500 mL ÷ {7 hours x 60}] x 15 = drops per minute

[500 ÷ 420] x 15 = drops per minute

1.19 x 15 = 17 to 18 drops per minute

e. Calculating IV rate-remaining time of infusion

- [Volume remaining (in mL) ÷ drops per minute] x drop factor = minutes remaining

Example:

A patient has 350 mL of Plain 0.9 NaCl solution as IV infusion regulated at 20 drops per minute.
Drop factor 10 was used for the patient’s macrodrip set. Considering the IV fluid level of the
patient, for how many minutes will it run?
Ateneo De Naga University
Naga City
College of Nursing

Review on Drug Calculations (SDL)


Renie Serrano

[Volume remaining (in mL) ÷ drops per minute] x drop factor = minutes remaining

[350 mL ÷ 20] x 10 = minutes remaining

17.5 x 10 = 175 minutes or 3 hours

You might also like