Medical Dosage Calculations (desired dose, IV drip rates, etc.)

Question 1

What is the formula for dosage calculations?

Answer 1

Desired Dose (DD) / On-Hand Dose (OH) × Quantity = Amount to Administer (AA)

Question 2

How do you calculate the amount to administer for a medication?

Answer 2

If the doctor orders 200 mg of a medication, and the available stock is 100 mg per tablet, use the formula to find the number of tablets to administer.

Example: 200 mg / 100 mg/tablet × 1 tablet = 2 tablets

Question 3

What is the formula for IV drip rate?

Answer 3

Volume to Infuse (mL) ÷ Time (min) = Drip Rate (mL/min)

Question 4

How do you calculate the drip rate for IV fluids?

Answer 4

If 500 mL of fluid needs to be administered over 2 hours, use the formula to calculate the drip rate in mL/min.

Example: 500 mL / 120 min = 4.17 mL/min

Question 5

What is the formula for flow rate using drip factor?

Answer 5

Volume to Infuse (mL) ÷ Time (hr) × Drip Factor (gtt/mL) = Flow Rate (gtt/min)

Question 6

How do you calculate the flow rate for IV fluids?

Answer 6

If 1,000 mL of fluid is to be administered over 4 hours with a drip factor of 20 gtt/mL, use the formula to find the flow rate in gtt/min.

Example: 1,000 mL / 4 hr × 20 gtt/mL = 83.33 gtt/min