Dosage Calculation

MAT110
MATH FOR NURSING

Math for Pharmacology

It doesn't have to be so hard!

It is important that you bring forward your knowledge of conversion factors from last quarter, including both metric and apothecary units of measurement.

Remember - you won't have access to the ladder, so you'll need to memorize it and 'brain dump' it before the test (same with your new formulas you'll be learning today!).

Draw

Convert the following. Draw your stair steps and write the # you calculate.

1.74 kg -> g

(Round to the nearest hundredth.)

Draw

Convert the following. Draw your stair steps and write the # you calculate.

1,745 mcg -> mg

(Round to the nearest hundredth.)

Draw

Convert the following. Draw your stair steps and write the # you calculate.

1.4789 g -> mg

(Round to the nearest hundredth.)

Hotspot

A nurse needs to convert 50kg to lbs.

Which conversion factor will she use?

We teach the formula method, but there are many other types! Your ATI modules explain all the other types... pick the one that works best for you!

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Math Formulas

Dose/Have Formula

A patient is prescribed amoxicillin at a dosage of 500 milligrams every 8 hours for a course of 7 days. The pharmacy dispenses amoxicillin in 250-milligram tablets. How many tablets should the patient take per dose?

Math Response

Your patient has ordered 100mg tablets of amoxicillin PO Q8H.

On hand is 50mg tablets of amoxicillin.

How many tablets of amoxicillin will you give?

Type answer here

Correct Answer: 2

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Math Response

A patient is prescribed a medication at a dosage of 15 milligrams per dose. How many milliliters of the medication should the patient receive if the concentration of the medication solution is 5 milligrams per milliliter?

Type answer here

Correct Answer: 3

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Math Response

A patient is prescribed a medication at a dosage of 750 milligrams per dose. The medication is available in a powdered form, and the pharmacist needs to prepare a solution with a concentration of 1.5g per 1,000mL. How many milliliters of the solution should the pharmacist prepare for a single dose?

Type answer here

Correct Answer: 500

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IV formula: Flow Rate

A patient requires an IV infusion of 1000 milliliters of saline solution over 8 hours.

Math Response

A patient needs to receive 500 milliliters of medication over a period of 4 hours using an infusion pump. The administration set has a drop factor of 20 drops per milliliter. What should the infusion rate be in milliliters per hour to administer the medication at the prescribed rate?

Type answer here

Correct Answer: 125

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Math Response

A patient needs to receive 1000 milliliters of intravenous fluid over 6 hours. The administration set has a drop factor of 15 drops per milliliter. What should the flow rate be in milliliters per hour to administer the fluid at the prescribed rate?

Round your answer to the nearest hundredth.

Type answer here

Correct Answer: 166.67

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Math Response

Some questions require multiple conversions within the question....

A patient needs to receive 100 mg of IV dextrose over the next hour. The IV dextrose is available as 1,000mg in 100mL. How should the nurse set the flow rate on the IV pump?

Type answer here

Correct Answer: 10

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IV formula: Gtt/min

A patient needs to receive 1000 milliliters of intravenous fluid over 6 hours. The administration set has a drop factor of 15 drops per milliliter. What will the drips/min be?

ALWAYS A WHOLE NUMBER!

Math Response

A patient requires an IV infusion of 1500 milliliters of antibiotics over a period of 12 hours. The administration set has a drop factor of 60 drops per milliliter. What should the drip rate be in drops per minute to deliver the antibiotics at the prescribed rate?

Type answer here

Correct Answer: 125

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Math Response

A patient requires an IV infusion of 1000 milliliters of saline solution over 6 hours. The administration set has a drip factor of 15 drops per milliliter. What should the drip rate be in drops per minute to deliver the saline solution at the prescribed rate?

Type answer here

Correct Answer: 42

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Math Response

A patient needs to receive 750 milliliters of medication over a period of 8 hours using an infusion pump. The administration set has a drip factor of 20 drops per milliliter. What should the drip rate be in drops per minute to deliver the solution at the prescribed rate?

Type answer here

Correct Answer: 31

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Rad