Drug bill
Table of contents
Units................................................................................................................................................................. 1
Rules to remember...........................................................................................................................................2
Conversions......................................................................................................................................................3
Concepts...........................................................................................................................................................4
Solid dosage forms...........................................................................................................................................5
Task examples of solid drugs............................................................................................................................6
Liquid dosage forms.........................................................................................................................................9
Task examples – liquid medicines...................................................................................................................10
Dilutions.........................................................................................................................................................12
Weight/volume percentage............................................................................................................................13
Infusions.........................................................................................................................................................16
REMEMBER TO READ THE UNIT (it must be converted to another unit before you can calculate
further)
Pharmacology = The study of drugs
Weight:
1 g = 100 mg = 1,000,000 micrograms
Volume:
1 L = 1000 ml = 1,000,000 microliters
Number:
1 mole = 1,000 mmol = 1,000,000 micromole
Units
• g = grams
• mg = milligram
Page 1of20
, • mikg = microgram
• mole = mole (e.g. sodium: there are 6x10 23 molecules. It is a very large number, which is
why the term mole is used)
• mmol = millimole
• l = liter
• ml = milliliter
• IU = International Units, and is a unit of measurement for the amount of a substance. IU
indicates the biological activity or effect of a substance and is internationally determined.
The unit is used to quantify e.g. vitamins, hormones, medicines and vaccines
Rules to remember
When converting from a larger unit to a smaller unit, e.g. from mg to mikg, you can choose the
following:
• Multiply by 1000 (i.e. the number becomes larger)
• Add 3 zeros
• Move the decimal point 3 places to the right
When converting from a smaller unit to a larger unit, e.g. mikg to mg, you can choose the following:
• Divide by 1000 (i.e. the number becomes smaller)
• Remove 3 zeros
• Move the decimal point 3 places to the left
Page 2of20
, Conversions
Conversion from g to mg
1g = 1000mg
2.5g = 2500mg
If you need to convert a number given in ig to mg, you must multiply the number by 1000.
Conversion from mg to g
1000 mg = 1 g
2340 mg = 2.34 g
If you need to convert a number given in mg to g, you must divide by 1000.
Conversion from mg to mikg
1 mg = 1000 micrograms
If you need to convert a number given in mg to mikg, you must multiply by 1000.
Conversion from mikg to mg:
15.689 micrograms = 15.689 mg
1 microgram = 0.001 mg
If you need to convert a number given in mikg to mg, you must divide by 1000.
Conversion from liters to ml:
1 L = 1000 ml
If you need to convert a number given in liters to ml, you must multiply by 1000.
Conversion from ml to liters:
1200 ml = 1.2 liters
500 ml = 0.5 liters
If you need to convert a number given in ml to liters, you must divide by 1000.
Page 3of20
Table of contents
Units................................................................................................................................................................. 1
Rules to remember...........................................................................................................................................2
Conversions......................................................................................................................................................3
Concepts...........................................................................................................................................................4
Solid dosage forms...........................................................................................................................................5
Task examples of solid drugs............................................................................................................................6
Liquid dosage forms.........................................................................................................................................9
Task examples – liquid medicines...................................................................................................................10
Dilutions.........................................................................................................................................................12
Weight/volume percentage............................................................................................................................13
Infusions.........................................................................................................................................................16
REMEMBER TO READ THE UNIT (it must be converted to another unit before you can calculate
further)
Pharmacology = The study of drugs
Weight:
1 g = 100 mg = 1,000,000 micrograms
Volume:
1 L = 1000 ml = 1,000,000 microliters
Number:
1 mole = 1,000 mmol = 1,000,000 micromole
Units
• g = grams
• mg = milligram
Page 1of20
, • mikg = microgram
• mole = mole (e.g. sodium: there are 6x10 23 molecules. It is a very large number, which is
why the term mole is used)
• mmol = millimole
• l = liter
• ml = milliliter
• IU = International Units, and is a unit of measurement for the amount of a substance. IU
indicates the biological activity or effect of a substance and is internationally determined.
The unit is used to quantify e.g. vitamins, hormones, medicines and vaccines
Rules to remember
When converting from a larger unit to a smaller unit, e.g. from mg to mikg, you can choose the
following:
• Multiply by 1000 (i.e. the number becomes larger)
• Add 3 zeros
• Move the decimal point 3 places to the right
When converting from a smaller unit to a larger unit, e.g. mikg to mg, you can choose the following:
• Divide by 1000 (i.e. the number becomes smaller)
• Remove 3 zeros
• Move the decimal point 3 places to the left
Page 2of20
, Conversions
Conversion from g to mg
1g = 1000mg
2.5g = 2500mg
If you need to convert a number given in ig to mg, you must multiply the number by 1000.
Conversion from mg to g
1000 mg = 1 g
2340 mg = 2.34 g
If you need to convert a number given in mg to g, you must divide by 1000.
Conversion from mg to mikg
1 mg = 1000 micrograms
If you need to convert a number given in mg to mikg, you must multiply by 1000.
Conversion from mikg to mg:
15.689 micrograms = 15.689 mg
1 microgram = 0.001 mg
If you need to convert a number given in mikg to mg, you must divide by 1000.
Conversion from liters to ml:
1 L = 1000 ml
If you need to convert a number given in liters to ml, you must multiply by 1000.
Conversion from ml to liters:
1200 ml = 1.2 liters
500 ml = 0.5 liters
If you need to convert a number given in ml to liters, you must divide by 1000.
Page 3of20
