Drug Calculations

 

1.                      How many milligrams of active ingredient are there in 0.3 ml of a 5% solution of metaproterenol (Alupent)?

 

50 mg /1 ml = x/0.3 ml

x = 50(0.3)

x = 15 mg

 

2.                      How many milliliters are needed to deliver 5.6 mg of a 2.25% solution of racemic epinephrine (Micro-Nefrin)?

 

22.5 mg /1 ml = 5.6 mg / x

22.5x = 5.6

x = 5.6 / 22.5

x = 0.25 ml

 

3.                      How many milligrams of active ingredient are there in 0.5 mL of a 1:200 (0.5%) solution of isoproterenol (Isuprel)?

 

5 mg / 1 ml = x / 0.5 ml

x = 5(0.5)

x = 2.5 mg

 

4.                      How many milliliters are needed to deliver 5 mg of a 1% solution of isoetharine (Bronkosol)?

 

10 mg / 1 ml = 5 mg / x

10x = 5

x = 5 / 10

x = 0.5 ml

 

5.                      How many milliliters are needed to deliver 2.5 mg of a 0.5% solution of albuterol (Proventil)?

               

5 mg / 1 ml = 2.5 mg / x

5x = 2.5

x = 0.5 ml

 

 

 

 

Answers to Practice Problems

 

1.                      How many milligrams of active ingredient are there in 0.3 ml of a 5% solution of metaproterenol (Alupent)?

 

                                                             i.      50 mg /1 ml = x/0.3 ml

                                                           ii.      x = 50(0.3)

                                                         iii.      x = 15 mg

 

2.                      How many milliliters are needed to deliver 5.6 mg of a 2.25% solution of racemic epinephrine (Micro-Nefrin)?

 

                                                             i.      22.5 mg /1 ml = 5.6 mg / x

                                                           ii.      22.5x = 5.6

                                                         iii.      x = 5.6 / 22.5

                                                        iv.      x = 0.25 ml

 

3.                      How many milligrams of active ingredient are there in 0.5 mL of a 1:200 (0.5%) solution of isoproterenol (Isuprel)?

 

                                                             i.      5 mg / 1 ml = x / 0.5 ml

                                                           ii.      x = 5(0.5)

                                                         iii.      x = 2.5 mg

 

4.                      How many milliliters are needed to deliver 5 mg of a 1% solution of isoetharine (Bronkosol)?

 

                                                             i.      10 mg / 1 ml = 5 mg / x

                                                           ii.      10x = 5

                                                         iii.      x = 5 / 10

                                                        iv.      x = 0.5 ml

 

5.                      How many milliliters are needed to deliver 2.5 mg of a 0.5% solution of albuterol (Proventil)?

 

                                                             i.      5 mg / 1 ml = 2.5 mg / x

                                                           ii.      5x = 2.5

                                                         iii.      x = 0.5 ml