Chapter 11

1. Chapter 11 Dosage Calculation Using Ratio and Proportion

2. Ratios • A ratio consists of two different numbers or qualities that have a significant relationship to each other.

3. Dosages • 50 mg = 1 tablet • 50 mg = 5 mL • 50 mg = 1 mL

4. 50 mg per tablet • If you have a 50 mg tablet and the physician order says to give 100 mg • 50 mg 1 tablet 100 mg = x tablets You would need to give 2 tablets

5. 50 mg in 5 mL • The physician order is to give 25 mg • The drug comes in a suspension of 50 mg / 5 mL • 50 mg5 mL 25 mg = x mL You would give 2.5 mL of the suspension to equal 25 mg of the drug.

6. 50 mg in 1 mL • The physician order is to give 25 mg of the drug. • 50 mg1 mL 25 mg = x mL You would give 0.5 mL of the drug to equal 25 mg.

7. 1500 mcg per tablet • The physician order states that you are to give 1.5 mg of the medication • How many tablets would you administer? • 1500 mcg = 1.5 mg • You would give one tablet

8. 1500 mcg per tablet • The physician order states to give 0.75 mg • 1500 mcg = 1.5 mg • 1.5 mg1 tablet 0.75 mg = x tablets You would administer ½ tablet to equal the correct dosage.

9. 200 mg in 5 mL • The physician orders 1 grain per year. • The child is 4 years old – you would need to give 4 grains • How may mgs in 4 grains? (60 x 4) = 240 mg • 200 mg5 mL 240 mg = x mL You would give 6 ml of the medication

10. 8 mg / 1 mL • The physician orders 10 mg of the drug. • 8 mg1 mL 10 mg = x mL You would administer 1.25 mL to equal 10 mg

11. 8 mg / 1 mL • The physician orders 6 mg of the drug. • 8mg1 mL 6 mg = x mL You would give 0.75 mL to equal 6 mg of the drug.

12. 25 mg / 1.5 mL • The order is for 20 mg of a drug. • 25 mg1.5 mL 20 mg = x mL You would administer 1.2 mL to equal 20 mg of the drug.

13. 160 mg / 0.8 mL • The physician orders 120 mg of the drug • 160 mg0.8 mL 120 mg = x mL You would give 0.6 mL of the drug to equal 120 mg.